CA2042497A1 - Safety interlock system for fastener driving tool - Google Patents
Safety interlock system for fastener driving toolInfo
- Publication number
- CA2042497A1 CA2042497A1 CA 2042497 CA2042497A CA2042497A1 CA 2042497 A1 CA2042497 A1 CA 2042497A1 CA 2042497 CA2042497 CA 2042497 CA 2042497 A CA2042497 A CA 2042497A CA 2042497 A1 CA2042497 A1 CA 2042497A1
- Authority
- CA
- Canada
- Prior art keywords
- trigger
- safety
- safety member
- relief
- recited
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25C—HAND-HELD NAILING OR STAPLING TOOLS; MANUALLY OPERATED PORTABLE STAPLING TOOLS
- B25C1/00—Hand-held nailing tools; Nail feeding devices
- B25C1/008—Safety devices
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Portable Nailing Machines And Staplers (AREA)
Abstract
Abstract of the Disclosure A fastener driving tool having a power mecha-nism operable during a fastener driving stroke to drive a fastener into a workpiece when an operator depresses a manually operable trigger and a safety member is in an actuated position. A safety mechanism for the fastener driving tool includes an interlock mechanism associated with the trigger and the safety member that assures that (1) the trigger will not be depressed from its standby position to its actuated position unless the safety mem-ber is moved to its actuated position; (2) the safety member will be locked into its standby position if the trigger is depressed prior to the safety member being depressed against the workpiece; (3) the trigger will be permitted to return toward its standby position even though the safety member is not fully engaged against the workpiece so that the fastener driving tool is reset to a static condition; (4) the trigger is permitted to return to its rest position only when the safety member is in its actuating position; and (5) the safety member will be prevented from returning from its actuated position to its standby position while the trigger is still in its firing position. In order to accomplish these safety interlock functions, the trigger has a trigger rod and the safety member has a series of reliefs into which the trigger rod may become lodged depending on the relative positions of the trigger and the safety member.
Description
2 ~ 7 SAFETY INTERLOCK SYSTEM FOR FASTENER DRIVING TOOL
CROSS REFERENCE TO R~LATED APPLICATION
This application is a continuation-in-part application of United States patent application Serial No. 07/523,704 filed on May 15, 1990 and is as~igned to the same assignee as the assignee of this application.
BACKGROUND OF THE_INVBNTION ..
the Inventio~ -.
The~present invention relates generally to a sa~ety mechanism for a fastener driving tool and more paxticularly, to a new and improved~safety mechanism ~ that insures that the ~astener driving tool will be ; actuated in~response to the actuation of a manually- ~;
operated trigger only after a sc~fety member of the fastener drivlng tool has been properly positioned 15 against a workpiece. ~;
2- ~ b~Y~ b~n~
Portable astenex driving tools are used . .
extensively in light manufacturing sectors. In its normal mode o~ operation, a ~astener driving tool is 20 actuated by air pressure so that a fastener, such as a nail, staple or the like, is ejected from a nosepiece of the ~astener driving tool into a workpiece during a driving stroke of the tool. The exceedingly high air pre~sures used (on the order o~ 100 pounds per square u 25 inch) results in the fastener being ejected from the tool with a great amount o~ Porce and at a high velocity.
' ".
2 ~ 9 7 Due to the force with which the fastener is ejected from the fastener driving tool, improper opera-tion of such a fastener driving tool can be hazardous.
A number of different safety mechanisms have been devised ~or such fastener driving tools in an attempt to eliminate accidental or inadvertent firing or actuation of the tool and injuries caused by the improper use of the tools. However, it has been found that those safety mechanisms do not insure that the ~astener driving tool will not be used in an improper ~ashion, especially i~
th~ safety mechanisms are compromised.
A number of safety mechanisms for such fastener driving tools include a workpiece contact engaging member which, if not depressed against the workpiece prior to the trigger of the fastener driving tool being depressed, prevents the fastener driving tool from being fired or actuated~ on the other hand, some safety mechanisms for fasten~r driving tool~ permit the operator of the tool to continue driving fasteners with ~:
successive bump~ of the workpiece contact engaging mem-ber by simply maintaining the trigger depressed. How-ever, operation of the fastener driving tool in this manner may be dangerous. - , Safety mechanisms for fastener driving tools .:
are disclosed in United States Patent No. 3,784,077 issued on ~anuary 8, 1974 and in United States Patent ~ .
No. 4,260,092 issued on April 7, 1981. The safety mech~
anis~s disclosed in those patents tend to prevent the disclo~ed ~astener driving tool from being act~ated to drive a ~astener if a workpiece engaging portion associ~
ated with the nosepiece of the ~astener driving tool is : .
not first depressed against a workpiece or if the work-piece engaging portion is not maintained depressed ayainst the workpiece. However, the trigger in these 35 d~vices may be pivoted or depressed without the work- .
piece engaging portion being depressed, thereby creating the possibility of accidental Piring, particularly i~
''''~ ' .,:
~ 20~2~97 ~
the safety mechanism is compromised through wear or mis-handling.
United States ~atent Nos. 3,464,614 and ::
CROSS REFERENCE TO R~LATED APPLICATION
This application is a continuation-in-part application of United States patent application Serial No. 07/523,704 filed on May 15, 1990 and is as~igned to the same assignee as the assignee of this application.
BACKGROUND OF THE_INVBNTION ..
the Inventio~ -.
The~present invention relates generally to a sa~ety mechanism for a fastener driving tool and more paxticularly, to a new and improved~safety mechanism ~ that insures that the ~astener driving tool will be ; actuated in~response to the actuation of a manually- ~;
operated trigger only after a sc~fety member of the fastener drivlng tool has been properly positioned 15 against a workpiece. ~;
2- ~ b~Y~ b~n~
Portable astenex driving tools are used . .
extensively in light manufacturing sectors. In its normal mode o~ operation, a ~astener driving tool is 20 actuated by air pressure so that a fastener, such as a nail, staple or the like, is ejected from a nosepiece of the ~astener driving tool into a workpiece during a driving stroke of the tool. The exceedingly high air pre~sures used (on the order o~ 100 pounds per square u 25 inch) results in the fastener being ejected from the tool with a great amount o~ Porce and at a high velocity.
' ".
2 ~ 9 7 Due to the force with which the fastener is ejected from the fastener driving tool, improper opera-tion of such a fastener driving tool can be hazardous.
A number of different safety mechanisms have been devised ~or such fastener driving tools in an attempt to eliminate accidental or inadvertent firing or actuation of the tool and injuries caused by the improper use of the tools. However, it has been found that those safety mechanisms do not insure that the ~astener driving tool will not be used in an improper ~ashion, especially i~
th~ safety mechanisms are compromised.
A number of safety mechanisms for such fastener driving tools include a workpiece contact engaging member which, if not depressed against the workpiece prior to the trigger of the fastener driving tool being depressed, prevents the fastener driving tool from being fired or actuated~ on the other hand, some safety mechanisms for fasten~r driving tool~ permit the operator of the tool to continue driving fasteners with ~:
successive bump~ of the workpiece contact engaging mem-ber by simply maintaining the trigger depressed. How-ever, operation of the fastener driving tool in this manner may be dangerous. - , Safety mechanisms for fastener driving tools .:
are disclosed in United States Patent No. 3,784,077 issued on ~anuary 8, 1974 and in United States Patent ~ .
No. 4,260,092 issued on April 7, 1981. The safety mech~
anis~s disclosed in those patents tend to prevent the disclo~ed ~astener driving tool from being act~ated to drive a ~astener if a workpiece engaging portion associ~
ated with the nosepiece of the ~astener driving tool is : .
not first depressed against a workpiece or if the work-piece engaging portion is not maintained depressed ayainst the workpiece. However, the trigger in these 35 d~vices may be pivoted or depressed without the work- .
piece engaging portion being depressed, thereby creating the possibility of accidental Piring, particularly i~
''''~ ' .,:
~ 20~2~97 ~
the safety mechanism is compromised through wear or mis-handling.
United States ~atent Nos. 3,464,614 and ::
3,519,186 also disclose safety mechanisms for a fastener driving tool. The safety mechanism disclosed in each of ~hose patents includes a blocking lever that will pre-vent the trigger of the fastener driving tocl from being depressed to actuate a driving stroke to drive a fas- :
tener unless a workpiece engaging portion is properly maintained against a workpiece. However, the trigger may be moved somewhat prior to the workpiece engaging por*ion being positioned against a workpiece. Moreover, the fastener driving tool is not permitted to return to its standby condition unless the trigger is released completely.
Some existing tools allow for c~ntinued actua- :
tion of the tool even though the workpiece engaging portion of the nosepiece partially returns toward its inoperative position, as for example, when the tool recoils after being actuated. This creates the possi-bility that a fastener inadvertently will be driven, perhaps on top of a previously d~eiven f~stener. ~:
Consequently, a need exists for a safety mech- ::
anism that prevents the trigger :Erom bPing depressed to actuate a ~riviny stroke of a fastener driving tool when th~ safety mechanism is not prop~rly placed against a workpiece, locks the safety mechanism into a non~
actuating mode when the trigger is even partially `
depressed prior to the safety member being positioned against a workpiece, but permits the resetting o~ the ~astener driving tool even if the safety member moveæ
slightly away from the workpiece, as for example, during recoil of the fastener driving tool.
SUMMAI~ a_____ENTION :
Accordingly, it is an object of the present ~nvention to provide a safety mechanism for a fastener 2 ~ 9 7 --4~
driving tool which overcomes de~iciencies in existing safety mechani ms for fastener driving tools.
Another object o~ ~he present invention is to provide a safety mechanism for a ~astener driving tool that only allows the trigger to be ~ully depressed to actuate a driving stroke of the fastener driving tool when a safety member is fully engaged with a workpiece.
Still another object of the present invention i~ to provide a safety mechanis~ for a fastener driving tool that prevents the tool from operating if a safety member is not first engaged with a workpiece. This is accompli~hed by a trigger lock-out mechanism whereby the trigger cannot be depressed ts initiate a ~astener driving stroke unless the tool is first engaged against a workpi~ce. An advantage of thi~ feature is the requirement imposed on the operator to first engage the safety member against the workpiece before depressing the trigger to eject a fastener.
A further object of the present invention is to provide a safety mechanism ~or a fastener driving tool that actually locks a safety member in an inopera~
tive po ition when the trigger of the fastener driving tool is depressed before the safety member is engaged against a workpiece. ~: :
Yet another object of the present invention is to prevent a fastener driving tool from being actuated - ~.
after ejection of a fastener if the safety member is not fully depressed against the workpiece, but nevertheless ~-permits the fastener driviny tool to be reset for actua- -30 tion of another driving stroke even if the safety member ~. .
i8 not completely depres~ed against the workpiece. This is accomplished by allowing the trigger to xeturn to a ~ :
transition position even if the tool raises slightly .~ :
~rom the-workpiece due to recoil but prohibits the trig- .
35 yer from again being depressed to actuate another driv- ::
iny ~troke until after the safety member again is fully :
engaged with the workpiece. : .
.
~2~97 ,~
In a~cordance with these and many otherobjects o the present invention, a fastener driving tool e~bodying the present invention includes a power mechanism operable during a fastener driving stroke to drive a fastener from a nosepiece of the tool into a workpiece. The fastener driving stroke is initiated by an operator depressing a manually operable trigger that is movable between a rest or inoperative position and a firing or operative positionO A workpiece engageable safety member is movably affixed on the nosepiece and is movable be~ween a standby or inoperative positlon and an actuated or operative position.
A afety mechanism for the fastener driving tool includes an interlock mechanism associated with both the trigger and the safety member. The interlock mechanism assures that (1) the trigger will not be :
depressed from its standby position to it~ actuated position unless the safety member is moved to its fully actuated or operative position by pressing the sa f ety member against a workpiece; (2) the safety member will be locked into its standby posit:ion as long as the trig- :
ger is being depressed toward it:s actuated position prior to the sa~ty member bein5~ depressed against the workpiece; (3) the trigger will be permitted to return toward its standby position everl though the safety mem-ber i~ not fully engaged against the workpiece such that ;
the fastener driving tool will be reset and ready for the initiation o~ another driving stroke as soon as the safety member again is fully d~pressed against the work- :
piece; (4) the trigger is permitted to return from its firing position to its full rest position only when the sa~ety member is in its full actuating position; and (5) the safe~y member will be prevented from returning rom its actuated position to its standby position while the trigger is still in its firing position. In order to ~ccomplish these safety interlock functions, the trigger has a trigger interlock portion including a trigger rod , -.
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~6-and the safety member has a sa~ety member interlock por-tion including a series of three relie~s. The trigger rod interacts with the safety member interlock portion and may b2come lodged in a particular one o~ the reliefs depending on the relative positions of the trigger and the sa~ety member.
BRIEF DESCRIPTION OF ~E DRAWINGS
Many other object~ and advantages oP the pre-~ent invention will become apparent from considering the ~ollowing detailed description o~ the embodiment of ths invention illustrated in the drawings, wherein:
FIG. 1 is a partially cut away side view of a portiQn of a fastener driving tool having a safety mech-anism em~)odying the present invention with the safety :
I5 member being fully extended to its standby, inoperative : position and the trigger being in its rest or inopera- .
tive position such that the ~ast~ner driving tool is in ~ .
a static mode: :
FIG. 2 is a partially cut-away front view of :-20 FIGo 1 taken along line 2-2 o~ FIG. 1;
FIG. 3 is a side view similar to FIG. 1 with the safety member being fully depressed to its actuated :.
position and the trigger 5 . ill in its inoperative posi~
tion; :~:
FIG. 4 is a side view similar to FIG. 1 with the safety member being f~lly depressed to its actuated ;~:
po~ition and the trigger also being ~ully depressed so that a driving stroke o~ the fastener driving tool is lnitlated; .
FIG. 5 is a side view similar to FIG. 1 with the ~afety member being displaced slightly from its ~ully depressed, actuated position and the trigger being : -moved slightly away ~rom its ~ully depressed position .;
a~ter a driving stroke of the ~astener driving ~QOl has been completed;
FIG. 6 is a side view similar to FIG. 1 with the safety member being partially depressed toward its 2~2~7 actuated pnsition and the trigger having been returnPd to a transition position so that the fastener driving tool i~ reset to a ~tatic mode;
FIG. 7 is a side v~ew similar to FIG. 1 with the safety member being locked in its ~ully extended, inoperative position due to the ~act that the trigger has b~en depressed somewhat from in its rest or inopera-tive positlon prior to the engagement of the sa~ety ~ember against a workpiece: and FIG. 8 i~ enlarged view of a portion of the fastenPr driving tool shown in FIG. 5 and in particular the ball valve used in the fa~tener driving toel and the mechanism by which the ball ~alve is actuated. -DETAXT~ED DESCRIPTION O~ THE PREFERRED EMBODIMEyT
Re~erring now ~ore specifically to FIG. 1 of ::.
the drawings, therein i~ disclosed a fastener driving tool 10 having a trigger and safety mechanism generally designated by the re~erence numeral 12 and embodying the pre ent invention. The fastener driving tool 10 may be :
one of several diPferent types of tools known in the art. One such tool i disclosed in United States Patent No. 3,fi83,746, the assignee of which is the assignee of record of the present application. The disclosure of . :
U.S. Patent No. 3,~683,746 is incorporated by reference herein. The fastener driving tool 10 is operable to drive ~asteners [not ~hown) into a workpiece (also not ::
shown) by ejecting fasteners from a nosepiece or nose : ~portion 14 of the fa~tener driving tool 10 when the nos2piece 14 is placed against the workpiece. ~ -In order for a fastener to be driven into the .
workpiece by the fastener driving tool 10, a driving stroke is initiated by depressing a trigger 16 so that the trigger 16 moves from an inoperative or rest posi-tion a~ illustrated in FIGS. 1 2 to an operative or ~iring position illustrated in FIG. 4. A manually operable safety membe.r 18 ~orming a portion of the trigger and safety mechanism 12 i8 movably mounted on "
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- .
~ 2~2~7 the nosepiece 14 of the fastener driving tool 10. The safety member 18 moves from an inoperative or standby position as illustrated in FIGS. 1-2 to an operative or actuating position as illustrated in FIGS. 3-4 when a workpiece engaging portion 20 of the safety member 18 is pushed and properly maintained against a workpiece.
Portions of the trigger 16 and the safety me~ber 18 for~ an safety interlock ~echanism generally referred to in the drawing~ by the reference numeral 22.
The sa~ety interlock mechanism 22 insures that (1~ the trlgger 16 will not be depressed Prom its standby po~ition to its actuated position unles the safety member 18 is moved to its fully actuated or operative ~:
position by pressing the safety member 18 against a 15 workpiece; (2) ~he safety member 18 will be locked into ~-it~ standby positio~ as long as the trigger 16 is being ~-.
depressed toward its actua~ed position prior to the :~
sa~ety member 18 being depressed against the workpiece;
(3) the trig~er 16 will be permitted to return toward its standby position even though the safety member 18 is : not fully engaged against the workpiece such that the -:
fastener driving tool 10 may be reset and ready for the initiation of another driving stroke as soon as the ~afety member 18 again is fully depressed against the : -25 workpiece; (~) the trigger 16 is permitted to return ~ -Prom its ~iring position to its full rest position only when the safety member 18 is in its full actuating posi~
tion; and (5) the safety member 18 will be prevented from returning from its actuating position to its standby position while the trigger 16 is still in its ~iring position.
As a result, the safety interlock mechanism 22 provides the fastPner driving tool 10 with various safety or interlock functions. In this regard, the trigger 16 cannot be depressed to actuate a driving stroke of the fastener driving tool 10 unless ~he safety member 18 is placed in its full, actuating position as , .,, , ,, ~ !, ...... , ' , . , , . , ~
- 2 ~ 9 7 g illustrated in FIG. 3 of the drawings by depressing the workpiece engaging portion 20 against the workpiece into which a ~astener is to be drivenO Moreover, the safety member 18 is per~itted to move from it~ actuating posi-tion to its standby position only when the trigg~r 16 isat its rest position. If the trigger 16 is depressed prior to the safety member 18 being moved towards its operative position illustrated in FIG. 3, the safety interlock mechanis~ 22 lock~ the safety member 18 in its -inoperative position until the trigger 16 is ~ully released Ssee PI~. 71. Another interlock mode is pro- . :
vided to prevent the recycling o~ the fastener driving tool 10 unless the safety ~ember 18 is in its fully actuated position. In this interlock mode, the trigger 15 16 is prevented ~rom returning to its ~irin~ position :
unless the safety member 18 is at it~ ~ully actuated ~:
positio~.
As previously indicated, a driving stroke of the ~astener driving tool 10 is initiated by the manual 20 depression of the trigger 16 by an operator. The trig- -ger 16 includes a trigger actuat:ing portion 24 extending from a pivotable portion 26. The pivotable portion 26 is pivotally mounted to the fast:ener driving tool 10 by a pin or rod 28. When a ~inger of an operator depresses or actuates the trigger actuating portion 24 and if the ~a~ety member 1~ i~ in its fully actuated or operative .
position shown in FIG. 3, the trigger 16 is permitted to rotat~ about th~ pin 28 in a generally counterclockwise dir~ction as the trigger 16 is viewed in FIGS. 1 and 3 of the drawings. As the trigger 16 is so rotated, pins 30 and 31 associated with a trigger valve 32 are dis-placed as shown in FIG. 4 and a driving stroke of the ~astaner driving tool 10 is initiated. More specifi-cally and as also is shown in FIG. 8 of the drawings, the pin 30 extends between an upper surface 34 of the trigger actuating portion 24 and a spring 36 that is dispo~ed about the pin 31. The pin 30 is hollow so that -: ' ' - ' ' , ' .:' ' ' i: ' ~ ' ., ,' , , ,, . . ~: : '. . . .
~ 2~2~7 the lower end of the pin 31 can extend into the pin 30.
A biasing spring 38 normally maintains the trigger 16 in ::
its inoperative position. As the trigger 16 is pivoted -~
about the pin 28 against the force o~ the biasing spring 5 38, the pin 30 will mova up as it i viewed in the : -drawing~ and as described in more detail below, th~ pin - :
31 also will be moved upward. As a result, the trigger valve 32 i5 closed and ~s will be described hereinafter a driving stroke oP th~ ~astener driving tool 10 is ~ ~
10 ini iated. :;:. .
A trigger interlock portion 39 ~orms the oppo-site end of the trigger 16 from the trigger actuating por~ion 24. The trigger interlock portion 39 also :-pivot~ about the pin 2~ and includes a trigger rsd or ~.
15 pin 40 that has its longitudinal axis generally perpen- :;
dicular to the longitudinal axis o~ the trigger 16. As will be descri~ed hereinafter, the trigger rod 40 inter- ~
acts with a safety member interlock portion 42 o~ the : ~ :
safety memher 18 so as to pro~ide ~he fastener driving ~ :
20 tool 10 with the various differe:nt safety:modes or ~ : :
features describ~d above.
~he safety me~ber 18 is slidably mounted about the no3epiece 14 o~ the fastener driving tool 10. It is biased to i~s standby or inoperative position illus-25 trated in FIGS. 1-2 and 7 by a biasing spring 44 that is mounted be~ween a lower surface 46 on a front end 48 of .
the ~astener driving tool 10 and a flange 50 extending rrOm a depending region 52 o~ th~ safety member ~8. The safety member 18 is generally S-shaped and include~ the depending region or linking portion 52 which extends between the workpi~ce engaging portion 20 and an inter~
mediate portio~ 54 that extends to the safety member interlock portion 42. The safety member interloc~ por-tion 42 is ~ecured to the intermediate portion 54 and 35 includes a projecting member 56 and three relie~s or ~;
recesse~ 58, 60, and 62 on a side 64 of ths safety .
' . '.. ' . ~ ' . ' ' ' ~' ~ ' ' -11- 20~2~97 member interlock portion 42 facing or adjacent to the trigger rod 40.
As previously indicated, the ~astener driving tool 10 i8 in its standby or static mode when the safety member 18 is in its inopsrative position and the trigger 16 i5 likewise in it~ inoperative position. Thi~ static mode of the factener driving tool 10 is illustrated in .
FXG. l-2 of the drawing~. When the ~asten r dri~ing tool lO i~ in thi3 static mode, th~ trigger valve 32 is open such that a trigger valve ball 65 i~ held against an O-ring seal 66 due to the high air pre~sure being supplied through an inlet line 68 and notwithst~nding the upper force being applied by the biasing spring 36.
As long a~ the trigger valve ball 65 is maintained 15 against the O-ring seal 66, the line 68 is maintained in ~
communication with an air line 70 and the driving blade o~ the fastener driving tool 10 is maintained in its static, non-driving condition.
As is ~een in FIG. 1, the trigger rod 40 is ~.
disposed adja~ent the projecting member 56 as long as the safety member 18 is maintainled in it~ inoperative position. I~ any attempt is mad~e to depress the trigger : ;
16 while the safety member 18 is in its inoperative position illustrated in FI~. l, the trigger rod 40 will become lodg~d in the upper r~lie~ 58 formed just above the projecting me~ber 56 (see; for example, FIG. 7 of the drawings). When the trigger rod 40 becomes so lodged in th~ relief 58, the trigger 16 cannot be depressed any further so that the trigger valve 32 will remain open. A~ a result, a driving stroke of the ~as-t~ner driving tool 10 cannot be initiated. Moreover, with the trigger rod 40 lodged in the relief 58, the saPety member 18 becomes locked in its inoperative posi-tion shown in FIG. 7 so that even i~ the workpiece eng~ging portion 20 o~ the afety member 18 is pressed again~t a workplece, the safety member l~ cannot be moved to its operative position as long as the trigger , . , . ~, ~ : , , : .
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2 ~ 7 ~ :
16 i~ being manually depressed. This insures that the safety features of the fastener driving tool 10 will not be overcome by an op~rator partially depressing the trigger 16 prior to the engage~ent of the safety member 5 18 against a workpiece. -:
In order for a driving ~troke of the fastener driviny tool 10 to be initiated, the workpiece engaging portion 20 o~ the safety member 18 ~ust be forced ~.
against a workpiece such that the sa~ety ~e~ber 18 will :-move relative to the nosepiece 14 o~ the ~astener driv~
inq tool 10 against the force of the spring ~4 to its operativ~ position shown in FIG. 3 of the drawings.
When the sa~ety member 18 is in its operative position, the lower relief 62 i~ exposed or becomes accessible to 15 the trigger rod 40. As a result, an operator of the :
~astener driving tool la may depress the trigger actuat-ing portion 24 of the trigger 16 upwardly as the trigger member 16 is viewed in FIG. 4 o the drawinys. As the trigger 1~ is so dapressed, the trigger rod 40 pivots in 20 an arcuate path such that the trigger rod 40 becomes .;~
: lodged in the lower relief 62 of the safety member interlock portion 42. At the same time, the upward ~::
movement o~ the upper surface 34 o~ the trigger actuat- :
ing portion 24 results in the displacement of the pin 30 upwardly such that the spring 36 associated with the trigger valv~ 32 is compressed. Once the force being ~
: ex~rted on the pin 31 through the spring 36 exceeds the :-amount of pressure exerted on the ball valve 65 by the . .-:
air pressure in the air inlet 68, the trigger valve ball 65 will move away ~rom the trigger valve 0-ring seal 66 and into a position sealing of~ the air inlet 68. With the air line 70 now in communication with an air exhaust ,~
port 72 and with the air inlet 68 so sealed, the air in the line 70 is exhausted to atmosphere through the air exhaust port 72 such that a driving stroke of the fas-tener driving tool 10 is initiated. A ~astener then i8 ' , ~2~7 13- :
driven into a workpiece on which the workpiece engaging portion 20 is lodgedO
As long as the trigger 16 remains in its ~ully operativ~ position illustrated in FIG. 4 o~ the draw-ings, the trigger valve 32 remains closed preventing areturn stroke of the fastener driving tool 10 such that another driving stroke o~ the fastener driving tool 10 cannot be initiated. on the other hand~ the trigger 16 may be released by the operator so a~ to be in the po i-tion disclosed in FIG. 3 i~ the saPety member 18 remainsin its fully actuated posi ion illustrated in FIG. 3 of the drawings. Another driving stroke then can be initi-ated by the operator again depressing the trigger 16. ..
~owever, the recoil and shock that is exerted against the fastPner driving tool lO as a result of the driving of a fastener into a workpi ce h~s a tendency to :~
rai~e the fastener driving tool lO away ~rom the work-piece such that the sa~ety member 18 moves slightly away ~rom its fully operative po ition. In addition, the operator tends to slightly relax his grip on the trigger member 16 due to this recoil. As a result, the fastener :
driving tool 10 i~ placed in a transition mode that is illustrated in FIGS. 5 and 8 of the drawings wherein the trigger membsr 16 i~ shown as having been moved slightly away from it fully actuated position and the safety membar 18 iS shown as having likewise moved slightly ;
away from its fully operative position. In this transi-tion mode, the trigger rod 40 is positioned somewhere between the lower relief 62 and the middle or transitory relie~ 60. Even though the trigger 16 has moved slightly away ~rom it~ fully actuated or operative posi-tion, the force exerted by the springs 36 on the pin 31 is su~icient to maintain the trigger valve ball 65 against the air inlet 68 notwithstanding the air pres-sura being applied against the ball valve 65 ~rom theair inlet 68. Consequently, the fa tener driving tool 10 i8 not returned to its static mode so that a return , ~ . . . .
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~troke of the fastaner driving tool 10 cannot be accom-plished and another driving stroke will not be initiated.
As the fastener driving tool 10 moves further away ~rom the workpiece, the spring 44 associated with the sa~ety member 18 moveis the ~aPety member 18 ~urther away Prom its fully operative position (see, for example) FIG. 6 of the drawings). When the safety mem- . :
ber 18 movas to thi~ position, the trigger ~od 40 is expo~ed to the relie~ 60 and the trigger 16 can be moved by the spring 38 towards its fully inoperative position.
Even thou~h the trigger rod 40 is disposed in the relief 60, the trigger 16 is preventad from returning to its ~ .
~ully inoperative positionO Nevertheless, the movement : .
of the trigger 16 to the transition position illustrated in FIG. 6 is su~Picient to relax the ~orce being applied to the trigger valve ball 65 by the biasing spring 36.
In response to this diminished force, the air pressure in the air inlet 68 is sufficient to move the trigger valve ball 65 against the 0-ring seal 66 and the trigger ~:
valve 32 again is opened. With the trigger valve 32 so open, the pneumatic circuit between the air inlet 68 and :
the air line 70 i8 reestablished so that a return stroke o~ the fa tener driving tool 10 is initiated and the ~
25 fastener driving tool 10 again is set in its static . - ;
mode. I~ the trigger 16 were prevented ~rom moving away fro~ it~ ~iring position as long as the saPety member 18 i8 not returnea to its fully inoperative position, a ;
~ast~ner may be inadvertently ejected from the fastener 30 driving tool 10 if the high air pressure source is ~
disconnected from the fastener driving tool 10 and later `
reconnected. This inadvertent driving of a fastener will not occur as long as the trigger 16 is allowed to return to the transition position illustrated in FIG. 6 o~ the drawings such that the ~astener driving tool 10 i8 reset to it static mode even though the safety member ~.
. , ~ .
~8 ha~ not been returned to it~ full inoperative pa~ition.
However, th~ repo3itioning of the trigg~r 16 in the transition positlon illustrated in FIG. 6 of the drawing~ doe~ not p~rmit another driving stroke to be initiated a~ long as the safety m~b~r 18 is in thi~
transitiv~ position because as long a3 the trigger rod 40 i~ di~po~ed in the middle reli~ 60, the trigger rod 40 i~ blocked by th~ æa~ety member interlock portion 42 - . .:
and th~ trigger 16 cannot b~ depre~.ed again to initiate anothçr driving stroke o~ the fastener driving ~ool 10. ~ .
It i~ only when th~ safety me~ber 18 again is returned ~:
to it~ ~ully operative po~ition as, for example, illus-trate~ in FIG. 3 of the drawings, that the triggex rod 40 is exposed to the lower relie~ area 62 and the trig-ger 1~ can be depressQd for ini~iation o~ another driv~
ing stroke.
Many modifications a~d variations of the present invention are possible in li~ht of the above teachingsO Thus, it is to be understood that, within the scope o~ th~ appended claim~, the invention may be practiced oth-r th~n a~ speci~ically dcs~ribed above.
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tener unless a workpiece engaging portion is properly maintained against a workpiece. However, the trigger may be moved somewhat prior to the workpiece engaging por*ion being positioned against a workpiece. Moreover, the fastener driving tool is not permitted to return to its standby condition unless the trigger is released completely.
Some existing tools allow for c~ntinued actua- :
tion of the tool even though the workpiece engaging portion of the nosepiece partially returns toward its inoperative position, as for example, when the tool recoils after being actuated. This creates the possi-bility that a fastener inadvertently will be driven, perhaps on top of a previously d~eiven f~stener. ~:
Consequently, a need exists for a safety mech- ::
anism that prevents the trigger :Erom bPing depressed to actuate a ~riviny stroke of a fastener driving tool when th~ safety mechanism is not prop~rly placed against a workpiece, locks the safety mechanism into a non~
actuating mode when the trigger is even partially `
depressed prior to the safety member being positioned against a workpiece, but permits the resetting o~ the ~astener driving tool even if the safety member moveæ
slightly away from the workpiece, as for example, during recoil of the fastener driving tool.
SUMMAI~ a_____ENTION :
Accordingly, it is an object of the present ~nvention to provide a safety mechanism for a fastener 2 ~ 9 7 --4~
driving tool which overcomes de~iciencies in existing safety mechani ms for fastener driving tools.
Another object o~ ~he present invention is to provide a safety mechanism for a ~astener driving tool that only allows the trigger to be ~ully depressed to actuate a driving stroke of the fastener driving tool when a safety member is fully engaged with a workpiece.
Still another object of the present invention i~ to provide a safety mechanis~ for a fastener driving tool that prevents the tool from operating if a safety member is not first engaged with a workpiece. This is accompli~hed by a trigger lock-out mechanism whereby the trigger cannot be depressed ts initiate a ~astener driving stroke unless the tool is first engaged against a workpi~ce. An advantage of thi~ feature is the requirement imposed on the operator to first engage the safety member against the workpiece before depressing the trigger to eject a fastener.
A further object of the present invention is to provide a safety mechanism ~or a fastener driving tool that actually locks a safety member in an inopera~
tive po ition when the trigger of the fastener driving tool is depressed before the safety member is engaged against a workpiece. ~: :
Yet another object of the present invention is to prevent a fastener driving tool from being actuated - ~.
after ejection of a fastener if the safety member is not fully depressed against the workpiece, but nevertheless ~-permits the fastener driviny tool to be reset for actua- -30 tion of another driving stroke even if the safety member ~. .
i8 not completely depres~ed against the workpiece. This is accomplished by allowing the trigger to xeturn to a ~ :
transition position even if the tool raises slightly .~ :
~rom the-workpiece due to recoil but prohibits the trig- .
35 yer from again being depressed to actuate another driv- ::
iny ~troke until after the safety member again is fully :
engaged with the workpiece. : .
.
~2~97 ,~
In a~cordance with these and many otherobjects o the present invention, a fastener driving tool e~bodying the present invention includes a power mechanism operable during a fastener driving stroke to drive a fastener from a nosepiece of the tool into a workpiece. The fastener driving stroke is initiated by an operator depressing a manually operable trigger that is movable between a rest or inoperative position and a firing or operative positionO A workpiece engageable safety member is movably affixed on the nosepiece and is movable be~ween a standby or inoperative positlon and an actuated or operative position.
A afety mechanism for the fastener driving tool includes an interlock mechanism associated with both the trigger and the safety member. The interlock mechanism assures that (1) the trigger will not be :
depressed from its standby position to it~ actuated position unless the safety member is moved to its fully actuated or operative position by pressing the sa f ety member against a workpiece; (2) the safety member will be locked into its standby posit:ion as long as the trig- :
ger is being depressed toward it:s actuated position prior to the sa~ty member bein5~ depressed against the workpiece; (3) the trigger will be permitted to return toward its standby position everl though the safety mem-ber i~ not fully engaged against the workpiece such that ;
the fastener driving tool will be reset and ready for the initiation o~ another driving stroke as soon as the safety member again is fully d~pressed against the work- :
piece; (4) the trigger is permitted to return from its firing position to its full rest position only when the sa~ety member is in its full actuating position; and (5) the safe~y member will be prevented from returning rom its actuated position to its standby position while the trigger is still in its firing position. In order to ~ccomplish these safety interlock functions, the trigger has a trigger interlock portion including a trigger rod , -.
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~6-and the safety member has a sa~ety member interlock por-tion including a series of three relie~s. The trigger rod interacts with the safety member interlock portion and may b2come lodged in a particular one o~ the reliefs depending on the relative positions of the trigger and the sa~ety member.
BRIEF DESCRIPTION OF ~E DRAWINGS
Many other object~ and advantages oP the pre-~ent invention will become apparent from considering the ~ollowing detailed description o~ the embodiment of ths invention illustrated in the drawings, wherein:
FIG. 1 is a partially cut away side view of a portiQn of a fastener driving tool having a safety mech-anism em~)odying the present invention with the safety :
I5 member being fully extended to its standby, inoperative : position and the trigger being in its rest or inopera- .
tive position such that the ~ast~ner driving tool is in ~ .
a static mode: :
FIG. 2 is a partially cut-away front view of :-20 FIGo 1 taken along line 2-2 o~ FIG. 1;
FIG. 3 is a side view similar to FIG. 1 with the safety member being fully depressed to its actuated :.
position and the trigger 5 . ill in its inoperative posi~
tion; :~:
FIG. 4 is a side view similar to FIG. 1 with the safety member being f~lly depressed to its actuated ;~:
po~ition and the trigger also being ~ully depressed so that a driving stroke o~ the fastener driving tool is lnitlated; .
FIG. 5 is a side view similar to FIG. 1 with the ~afety member being displaced slightly from its ~ully depressed, actuated position and the trigger being : -moved slightly away ~rom its ~ully depressed position .;
a~ter a driving stroke of the ~astener driving ~QOl has been completed;
FIG. 6 is a side view similar to FIG. 1 with the safety member being partially depressed toward its 2~2~7 actuated pnsition and the trigger having been returnPd to a transition position so that the fastener driving tool i~ reset to a ~tatic mode;
FIG. 7 is a side v~ew similar to FIG. 1 with the safety member being locked in its ~ully extended, inoperative position due to the ~act that the trigger has b~en depressed somewhat from in its rest or inopera-tive positlon prior to the engagement of the sa~ety ~ember against a workpiece: and FIG. 8 i~ enlarged view of a portion of the fastenPr driving tool shown in FIG. 5 and in particular the ball valve used in the fa~tener driving toel and the mechanism by which the ball ~alve is actuated. -DETAXT~ED DESCRIPTION O~ THE PREFERRED EMBODIMEyT
Re~erring now ~ore specifically to FIG. 1 of ::.
the drawings, therein i~ disclosed a fastener driving tool 10 having a trigger and safety mechanism generally designated by the re~erence numeral 12 and embodying the pre ent invention. The fastener driving tool 10 may be :
one of several diPferent types of tools known in the art. One such tool i disclosed in United States Patent No. 3,fi83,746, the assignee of which is the assignee of record of the present application. The disclosure of . :
U.S. Patent No. 3,~683,746 is incorporated by reference herein. The fastener driving tool 10 is operable to drive ~asteners [not ~hown) into a workpiece (also not ::
shown) by ejecting fasteners from a nosepiece or nose : ~portion 14 of the fa~tener driving tool 10 when the nos2piece 14 is placed against the workpiece. ~ -In order for a fastener to be driven into the .
workpiece by the fastener driving tool 10, a driving stroke is initiated by depressing a trigger 16 so that the trigger 16 moves from an inoperative or rest posi-tion a~ illustrated in FIGS. 1 2 to an operative or ~iring position illustrated in FIG. 4. A manually operable safety membe.r 18 ~orming a portion of the trigger and safety mechanism 12 i8 movably mounted on "
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- .
~ 2~2~7 the nosepiece 14 of the fastener driving tool 10. The safety member 18 moves from an inoperative or standby position as illustrated in FIGS. 1-2 to an operative or actuating position as illustrated in FIGS. 3-4 when a workpiece engaging portion 20 of the safety member 18 is pushed and properly maintained against a workpiece.
Portions of the trigger 16 and the safety me~ber 18 for~ an safety interlock ~echanism generally referred to in the drawing~ by the reference numeral 22.
The sa~ety interlock mechanism 22 insures that (1~ the trlgger 16 will not be depressed Prom its standby po~ition to its actuated position unles the safety member 18 is moved to its fully actuated or operative ~:
position by pressing the safety member 18 against a 15 workpiece; (2) ~he safety member 18 will be locked into ~-it~ standby positio~ as long as the trigger 16 is being ~-.
depressed toward its actua~ed position prior to the :~
sa~ety member 18 being depressed against the workpiece;
(3) the trig~er 16 will be permitted to return toward its standby position even though the safety member 18 is : not fully engaged against the workpiece such that the -:
fastener driving tool 10 may be reset and ready for the initiation of another driving stroke as soon as the ~afety member 18 again is fully depressed against the : -25 workpiece; (~) the trigger 16 is permitted to return ~ -Prom its ~iring position to its full rest position only when the safety member 18 is in its full actuating posi~
tion; and (5) the safety member 18 will be prevented from returning from its actuating position to its standby position while the trigger 16 is still in its ~iring position.
As a result, the safety interlock mechanism 22 provides the fastPner driving tool 10 with various safety or interlock functions. In this regard, the trigger 16 cannot be depressed to actuate a driving stroke of the fastener driving tool 10 unless ~he safety member 18 is placed in its full, actuating position as , .,, , ,, ~ !, ...... , ' , . , , . , ~
- 2 ~ 9 7 g illustrated in FIG. 3 of the drawings by depressing the workpiece engaging portion 20 against the workpiece into which a ~astener is to be drivenO Moreover, the safety member 18 is per~itted to move from it~ actuating posi-tion to its standby position only when the trigg~r 16 isat its rest position. If the trigger 16 is depressed prior to the safety member 18 being moved towards its operative position illustrated in FIG. 3, the safety interlock mechanis~ 22 lock~ the safety member 18 in its -inoperative position until the trigger 16 is ~ully released Ssee PI~. 71. Another interlock mode is pro- . :
vided to prevent the recycling o~ the fastener driving tool 10 unless the safety ~ember 18 is in its fully actuated position. In this interlock mode, the trigger 15 16 is prevented ~rom returning to its ~irin~ position :
unless the safety member 18 is at it~ ~ully actuated ~:
positio~.
As previously indicated, a driving stroke of the ~astener driving tool 10 is initiated by the manual 20 depression of the trigger 16 by an operator. The trig- -ger 16 includes a trigger actuat:ing portion 24 extending from a pivotable portion 26. The pivotable portion 26 is pivotally mounted to the fast:ener driving tool 10 by a pin or rod 28. When a ~inger of an operator depresses or actuates the trigger actuating portion 24 and if the ~a~ety member 1~ i~ in its fully actuated or operative .
position shown in FIG. 3, the trigger 16 is permitted to rotat~ about th~ pin 28 in a generally counterclockwise dir~ction as the trigger 16 is viewed in FIGS. 1 and 3 of the drawings. As the trigger 16 is so rotated, pins 30 and 31 associated with a trigger valve 32 are dis-placed as shown in FIG. 4 and a driving stroke of the ~astaner driving tool 10 is initiated. More specifi-cally and as also is shown in FIG. 8 of the drawings, the pin 30 extends between an upper surface 34 of the trigger actuating portion 24 and a spring 36 that is dispo~ed about the pin 31. The pin 30 is hollow so that -: ' ' - ' ' , ' .:' ' ' i: ' ~ ' ., ,' , , ,, . . ~: : '. . . .
~ 2~2~7 the lower end of the pin 31 can extend into the pin 30.
A biasing spring 38 normally maintains the trigger 16 in ::
its inoperative position. As the trigger 16 is pivoted -~
about the pin 28 against the force o~ the biasing spring 5 38, the pin 30 will mova up as it i viewed in the : -drawing~ and as described in more detail below, th~ pin - :
31 also will be moved upward. As a result, the trigger valve 32 i5 closed and ~s will be described hereinafter a driving stroke oP th~ ~astener driving tool 10 is ~ ~
10 ini iated. :;:. .
A trigger interlock portion 39 ~orms the oppo-site end of the trigger 16 from the trigger actuating por~ion 24. The trigger interlock portion 39 also :-pivot~ about the pin 2~ and includes a trigger rsd or ~.
15 pin 40 that has its longitudinal axis generally perpen- :;
dicular to the longitudinal axis o~ the trigger 16. As will be descri~ed hereinafter, the trigger rod 40 inter- ~
acts with a safety member interlock portion 42 o~ the : ~ :
safety memher 18 so as to pro~ide ~he fastener driving ~ :
20 tool 10 with the various differe:nt safety:modes or ~ : :
features describ~d above.
~he safety me~ber 18 is slidably mounted about the no3epiece 14 o~ the fastener driving tool 10. It is biased to i~s standby or inoperative position illus-25 trated in FIGS. 1-2 and 7 by a biasing spring 44 that is mounted be~ween a lower surface 46 on a front end 48 of .
the ~astener driving tool 10 and a flange 50 extending rrOm a depending region 52 o~ th~ safety member ~8. The safety member 18 is generally S-shaped and include~ the depending region or linking portion 52 which extends between the workpi~ce engaging portion 20 and an inter~
mediate portio~ 54 that extends to the safety member interlock portion 42. The safety member interloc~ por-tion 42 is ~ecured to the intermediate portion 54 and 35 includes a projecting member 56 and three relie~s or ~;
recesse~ 58, 60, and 62 on a side 64 of ths safety .
' . '.. ' . ~ ' . ' ' ' ~' ~ ' ' -11- 20~2~97 member interlock portion 42 facing or adjacent to the trigger rod 40.
As previously indicated, the ~astener driving tool 10 i8 in its standby or static mode when the safety member 18 is in its inopsrative position and the trigger 16 i5 likewise in it~ inoperative position. Thi~ static mode of the factener driving tool 10 is illustrated in .
FXG. l-2 of the drawing~. When the ~asten r dri~ing tool lO i~ in thi3 static mode, th~ trigger valve 32 is open such that a trigger valve ball 65 i~ held against an O-ring seal 66 due to the high air pre~sure being supplied through an inlet line 68 and notwithst~nding the upper force being applied by the biasing spring 36.
As long a~ the trigger valve ball 65 is maintained 15 against the O-ring seal 66, the line 68 is maintained in ~
communication with an air line 70 and the driving blade o~ the fastener driving tool 10 is maintained in its static, non-driving condition.
As is ~een in FIG. 1, the trigger rod 40 is ~.
disposed adja~ent the projecting member 56 as long as the safety member 18 is maintainled in it~ inoperative position. I~ any attempt is mad~e to depress the trigger : ;
16 while the safety member 18 is in its inoperative position illustrated in FI~. l, the trigger rod 40 will become lodg~d in the upper r~lie~ 58 formed just above the projecting me~ber 56 (see; for example, FIG. 7 of the drawings). When the trigger rod 40 becomes so lodged in th~ relief 58, the trigger 16 cannot be depressed any further so that the trigger valve 32 will remain open. A~ a result, a driving stroke of the ~as-t~ner driving tool 10 cannot be initiated. Moreover, with the trigger rod 40 lodged in the relief 58, the saPety member 18 becomes locked in its inoperative posi-tion shown in FIG. 7 so that even i~ the workpiece eng~ging portion 20 o~ the afety member 18 is pressed again~t a workplece, the safety member l~ cannot be moved to its operative position as long as the trigger , . , . ~, ~ : , , : .
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2 ~ 7 ~ :
16 i~ being manually depressed. This insures that the safety features of the fastener driving tool 10 will not be overcome by an op~rator partially depressing the trigger 16 prior to the engage~ent of the safety member 5 18 against a workpiece. -:
In order for a driving ~troke of the fastener driviny tool 10 to be initiated, the workpiece engaging portion 20 o~ the safety member 18 ~ust be forced ~.
against a workpiece such that the sa~ety ~e~ber 18 will :-move relative to the nosepiece 14 o~ the ~astener driv~
inq tool 10 against the force of the spring ~4 to its operativ~ position shown in FIG. 3 of the drawings.
When the sa~ety member 18 is in its operative position, the lower relief 62 i~ exposed or becomes accessible to 15 the trigger rod 40. As a result, an operator of the :
~astener driving tool la may depress the trigger actuat-ing portion 24 of the trigger 16 upwardly as the trigger member 16 is viewed in FIG. 4 o the drawinys. As the trigger 1~ is so dapressed, the trigger rod 40 pivots in 20 an arcuate path such that the trigger rod 40 becomes .;~
: lodged in the lower relief 62 of the safety member interlock portion 42. At the same time, the upward ~::
movement o~ the upper surface 34 o~ the trigger actuat- :
ing portion 24 results in the displacement of the pin 30 upwardly such that the spring 36 associated with the trigger valv~ 32 is compressed. Once the force being ~
: ex~rted on the pin 31 through the spring 36 exceeds the :-amount of pressure exerted on the ball valve 65 by the . .-:
air pressure in the air inlet 68, the trigger valve ball 65 will move away ~rom the trigger valve 0-ring seal 66 and into a position sealing of~ the air inlet 68. With the air line 70 now in communication with an air exhaust ,~
port 72 and with the air inlet 68 so sealed, the air in the line 70 is exhausted to atmosphere through the air exhaust port 72 such that a driving stroke of the fas-tener driving tool 10 is initiated. A ~astener then i8 ' , ~2~7 13- :
driven into a workpiece on which the workpiece engaging portion 20 is lodgedO
As long as the trigger 16 remains in its ~ully operativ~ position illustrated in FIG. 4 o~ the draw-ings, the trigger valve 32 remains closed preventing areturn stroke of the fastener driving tool 10 such that another driving stroke o~ the fastener driving tool 10 cannot be initiated. on the other hand~ the trigger 16 may be released by the operator so a~ to be in the po i-tion disclosed in FIG. 3 i~ the saPety member 18 remainsin its fully actuated posi ion illustrated in FIG. 3 of the drawings. Another driving stroke then can be initi-ated by the operator again depressing the trigger 16. ..
~owever, the recoil and shock that is exerted against the fastPner driving tool lO as a result of the driving of a fastener into a workpi ce h~s a tendency to :~
rai~e the fastener driving tool lO away ~rom the work-piece such that the sa~ety member 18 moves slightly away ~rom its fully operative po ition. In addition, the operator tends to slightly relax his grip on the trigger member 16 due to this recoil. As a result, the fastener :
driving tool 10 i~ placed in a transition mode that is illustrated in FIGS. 5 and 8 of the drawings wherein the trigger membsr 16 i~ shown as having been moved slightly away from it fully actuated position and the safety membar 18 iS shown as having likewise moved slightly ;
away from its fully operative position. In this transi-tion mode, the trigger rod 40 is positioned somewhere between the lower relief 62 and the middle or transitory relie~ 60. Even though the trigger 16 has moved slightly away ~rom it~ fully actuated or operative posi-tion, the force exerted by the springs 36 on the pin 31 is su~icient to maintain the trigger valve ball 65 against the air inlet 68 notwithstanding the air pres-sura being applied against the ball valve 65 ~rom theair inlet 68. Consequently, the fa tener driving tool 10 i8 not returned to its static mode so that a return , ~ . . . .
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~troke of the fastaner driving tool 10 cannot be accom-plished and another driving stroke will not be initiated.
As the fastener driving tool 10 moves further away ~rom the workpiece, the spring 44 associated with the sa~ety member 18 moveis the ~aPety member 18 ~urther away Prom its fully operative position (see, for example) FIG. 6 of the drawings). When the safety mem- . :
ber 18 movas to thi~ position, the trigger ~od 40 is expo~ed to the relie~ 60 and the trigger 16 can be moved by the spring 38 towards its fully inoperative position.
Even thou~h the trigger rod 40 is disposed in the relief 60, the trigger 16 is preventad from returning to its ~ .
~ully inoperative positionO Nevertheless, the movement : .
of the trigger 16 to the transition position illustrated in FIG. 6 is su~Picient to relax the ~orce being applied to the trigger valve ball 65 by the biasing spring 36.
In response to this diminished force, the air pressure in the air inlet 68 is sufficient to move the trigger valve ball 65 against the 0-ring seal 66 and the trigger ~:
valve 32 again is opened. With the trigger valve 32 so open, the pneumatic circuit between the air inlet 68 and :
the air line 70 i8 reestablished so that a return stroke o~ the fa tener driving tool 10 is initiated and the ~
25 fastener driving tool 10 again is set in its static . - ;
mode. I~ the trigger 16 were prevented ~rom moving away fro~ it~ ~iring position as long as the saPety member 18 i8 not returnea to its fully inoperative position, a ;
~ast~ner may be inadvertently ejected from the fastener 30 driving tool 10 if the high air pressure source is ~
disconnected from the fastener driving tool 10 and later `
reconnected. This inadvertent driving of a fastener will not occur as long as the trigger 16 is allowed to return to the transition position illustrated in FIG. 6 o~ the drawings such that the ~astener driving tool 10 i8 reset to it static mode even though the safety member ~.
. , ~ .
~8 ha~ not been returned to it~ full inoperative pa~ition.
However, th~ repo3itioning of the trigg~r 16 in the transition positlon illustrated in FIG. 6 of the drawing~ doe~ not p~rmit another driving stroke to be initiated a~ long as the safety m~b~r 18 is in thi~
transitiv~ position because as long a3 the trigger rod 40 i~ di~po~ed in the middle reli~ 60, the trigger rod 40 i~ blocked by th~ æa~ety member interlock portion 42 - . .:
and th~ trigger 16 cannot b~ depre~.ed again to initiate anothçr driving stroke o~ the fastener driving ~ool 10. ~ .
It i~ only when th~ safety me~ber 18 again is returned ~:
to it~ ~ully operative po~ition as, for example, illus-trate~ in FIG. 3 of the drawings, that the triggex rod 40 is exposed to the lower relie~ area 62 and the trig-ger 1~ can be depressQd for ini~iation o~ another driv~
ing stroke.
Many modifications a~d variations of the present invention are possible in li~ht of the above teachingsO Thus, it is to be understood that, within the scope o~ th~ appended claim~, the invention may be practiced oth-r th~n a~ speci~ically dcs~ribed above.
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Claims (21)
1. A safety mechanism for a fastener driving tool having power means operable in a fastener driving stroke in which a fastener is driven into a workpiece, said mechanism comprising:
a manually operable safety member movable between a safety standby position and a safety actuated position;
a manually operable trigger movable between a trigger inoperative position and a trigger operative position;
control means associated with said power means and said trigger for initiating a driving stroke only when said control means is changed from a control inoperative state to a control operative state by the movement of said trigger to said trigger operative position; and interlock means defined on said trigger and on said safety member for:
(i) locking said safety member in said safety standby position when said trigger is moved from said trigger inoperative position and said safety member is in said safety standby position;
(ii) permitting said trigger to move into said trigger operative position only when said safety member is in said safety actuated position;
(iii) permitting said trigger to return from said trigger operative position to said trigger inoperative position only when said safety member is in said safety actuated position;
(iv) preventing said safety member from returning from said safety actuated position to said safety standby position while said trigger is in said trigger operative position; and (v) permitting said trigger to reset said control means to said control inoperative state even though said safety member is displaced from said safety actuated position.
a manually operable safety member movable between a safety standby position and a safety actuated position;
a manually operable trigger movable between a trigger inoperative position and a trigger operative position;
control means associated with said power means and said trigger for initiating a driving stroke only when said control means is changed from a control inoperative state to a control operative state by the movement of said trigger to said trigger operative position; and interlock means defined on said trigger and on said safety member for:
(i) locking said safety member in said safety standby position when said trigger is moved from said trigger inoperative position and said safety member is in said safety standby position;
(ii) permitting said trigger to move into said trigger operative position only when said safety member is in said safety actuated position;
(iii) permitting said trigger to return from said trigger operative position to said trigger inoperative position only when said safety member is in said safety actuated position;
(iv) preventing said safety member from returning from said safety actuated position to said safety standby position while said trigger is in said trigger operative position; and (v) permitting said trigger to reset said control means to said control inoperative state even though said safety member is displaced from said safety actuated position.
2. A mechanism as recited in claim 1 including biasing means to bias said trigger toward said trigger inoperative position.
3. A mechanism as recited in claim 1 wherein the safety member is slidably attached to the fastener driving tool and includes a safety member biasing means biasing said safety member towards its standby position.
4. A mechanism as recited in claim 1 wherein said safety member includes a workpiece engaging portion and a safety interlock portion forming a portion of said interlock means, the movement of said safety interlock portion being controlled by the movement of said workpiece engaging portion.
5. A mechanism as recited in claim 4 wherein said safety interlock portion includes a plurality of reliefs and said trigger includes a trigger safety means, said trigger safety means being movable into one of said reliefs depending on the position of said safety interlock portion and the movement of said trigger.
6. A mechanism as recited in claim 5 wherein said plurality of reliefs on said safety interlock portion includes a first relief, a second relief, and a third relief.
7. A mechanism as recited in claim 6 wherein said first relief is positioned relative to said trigger safety means of said trigger such that said trigger safety means becomes lodged in said first relief when said safety member is in said safety standby position and said trigger is moved from said trigger inoperative position whereby said safety member is locked in said safety standby position.
8. A mechanism as recited in claim 6 wherein said third relief is positioned relative to said trigger safety means such that said trigger safety means may become disposed in said third relief when said safety member is in said safety actuated position and said trigger is moved to said trigger operative position, the movement of said trigger to said trigger operative position results in said control means being changed from said control inoperative state to said control operative state to thereby initiate a fastener driving stroke of said fastener driving tool.
9. A mechanism as recited in claim 6 wherein said second relief is positioned between said first and third reliefs and said trigger safety means may become disposed in said second relief when said safety member is moved slightly away from said safety actuated position and said trigger moves towards said trigger inoperative position such that said control means is reset to said control inoperative state.
10. A mechanism as recited in claim 6 wherein said movement of said trigger towards said trigger operative position moves said trigger safety means in an arcuate path so that it may become lodged in said first, second or third relief depending on the position of said safety member.
11. A mechanism as recited in claim 1 wherein said control means includes a valve means that controls the initiation of said fastener driving stroke, said valve means normally being maintained in a first valve state and being operated to a second valve state in response to the movement of said trigger to said trigger operative position.
12. A mechanism as recited in claim 11 including a valve spring means disposed between said trigger and said valve means, said spring means being responsive to the movement of said trigger.
13. A mechanism as recited in claim 12 wherein said valve means is maintained in said first valve state by air pressure exerted against said valve means and is operated to a second valve state in response to the movement of said trigger to said trigger operative position whereby said valve spring means forces said valve means into said second valve state.
14. A safety mechanism for a fastener driving tool having power means operable in a fastener driving stroke in which a fastener is driven into a workpiece, said mechanism comprising:
a manually operable safety member movable between a safety inoperative position and a safety actuated position;
a manually operable trigger movable between a trigger rest position and a trigger firing position;
control means associated with said power means and said trigger for initiating a driving stroke only when said control means is changed from a control standby state to a control actuated state by the movement of said trigger to said trigger firing position; and interlock means defined on said trigger and on said safety member for locking said safety member in said safety inoperative position when said trigger is moved from said trigger rest position and said safety member is in said safety inoperative position.
a manually operable safety member movable between a safety inoperative position and a safety actuated position;
a manually operable trigger movable between a trigger rest position and a trigger firing position;
control means associated with said power means and said trigger for initiating a driving stroke only when said control means is changed from a control standby state to a control actuated state by the movement of said trigger to said trigger firing position; and interlock means defined on said trigger and on said safety member for locking said safety member in said safety inoperative position when said trigger is moved from said trigger rest position and said safety member is in said safety inoperative position.
15. A mechanism as recited in claim 14 wherein said safety member includes a workpiece engaging portion and a safety interlock portion forming a portion of said interlock means, the movement of said safety interlock portion being controlled by the movement of said workpiece engaging portion.
16. A mechanism as recited in claim 15 wherein said safety interlock portion includes at least one relief and said trigger includes a trigger safety means, said relief being positioned relative to said trigger safety means of said trigger such that said trigger safety means becomes lodged in said relief when said safety member is in said safety inoperative position and said trigger is moved from said trigger rest position so as to lock said safety member in said safety inoperative position.
17. A mechanism as recited in claim 16 wherein said movement of said trigger toward said trigger firing position moves said trigger safety means in an arcuate path so that it becomes lodged in said relief when said safety member is in said safety inoperative position.
18. A safety mechanism for a fastener driving tool having power means operable in a fasten r driving stroke in which a fastener is driven into a workpiece, said mechanism comprising:
a manually operable safety member movable between a safety inoperative position and a safety actuated position;
a manually operable trigger movable between a trigger rest position and a trigger firing position;
control means associated with said power means and said trigger for initiating a driving stroke only when said control means is changed from a control standby state to a control actuated state by the movement of said trigger to said trigger firing position; and interlock means defined on said trigger and on said safety member for permitting said trigger to move into said trigger firing position only when said safety member is in said safety actuated position, for permitting said trigger to return from said trigger firing position to said trigger rest position only when said safety member is in said safety actuated position, for preventing said safety member from returning from said safety actuated position to said safety inoperative position while said trigger is in said trigger firing position, and for permitting said trigger to reset said control means to said control standby state even though said safety member is displaced from said safety actuated position.
a manually operable safety member movable between a safety inoperative position and a safety actuated position;
a manually operable trigger movable between a trigger rest position and a trigger firing position;
control means associated with said power means and said trigger for initiating a driving stroke only when said control means is changed from a control standby state to a control actuated state by the movement of said trigger to said trigger firing position; and interlock means defined on said trigger and on said safety member for permitting said trigger to move into said trigger firing position only when said safety member is in said safety actuated position, for permitting said trigger to return from said trigger firing position to said trigger rest position only when said safety member is in said safety actuated position, for preventing said safety member from returning from said safety actuated position to said safety inoperative position while said trigger is in said trigger firing position, and for permitting said trigger to reset said control means to said control standby state even though said safety member is displaced from said safety actuated position.
19. A mechanism as recited in claim 18 wherein said safety member includes a workpiece engaging portion and a safety interlock portion forming a portion of said interlock means, the movement of said safety interlock portion being controlled by the movement of said workpiece engaging portion.
20. A mechanism as recited in claim 19 wherein said safety interlock portion includes at least a transition relief and a firing relief and said trigger includes a trigger safety means, said firing relief being positioned relative to said trigger safety means of said trigger such that said trigger safety means becomes lodged in said firing relief when said safety member is in said safety actuated position and said trigger is moved from said trigger rest position to said trigger firing position.
21. A mechanism as recited in claim 20 wherein said transition relief is positioned relative to said trigger safety means of said trigger such that said trigger safety means becomes lodged in said transition relief when said safety member is moved slightly away from said safety actuated position and said trigger moves towards said trigger rest position such that said control means is reset to said control standby state from said control actuated state.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US07/523,704 | 1990-05-15 | ||
| US07/523,704 US5035354A (en) | 1990-05-15 | 1990-05-15 | Safety dual-interlock system for fastener driving tool |
| US69121391A | 1991-04-30 | 1991-04-30 | |
| US07/691,213 | 1991-04-30 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2042497A1 true CA2042497A1 (en) | 1991-11-16 |
Family
ID=27061231
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2042497 Abandoned CA2042497A1 (en) | 1990-05-15 | 1991-05-14 | Safety interlock system for fastener driving tool |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0457305A1 (en) |
| JP (1) | JPH0679649A (en) |
| AU (1) | AU7704691A (en) |
| CA (1) | CA2042497A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6648202B2 (en) | 2001-02-08 | 2003-11-18 | Black & Decker Inc. | Pneumatic fastening tool |
| TW200942375A (en) * | 2008-04-07 | 2009-10-16 | Basso Ind Corp | Nail gun with safety device |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3784077A (en) * | 1972-05-05 | 1974-01-08 | Textron Inc | Portable pneumatic fastener driving device with improved actuating mechanism |
| CA1093753A (en) * | 1978-07-05 | 1981-01-20 | Raymond F. Novak | Electric brad nailer |
| US4260092A (en) * | 1979-07-02 | 1981-04-07 | Duo-Fast Corporation | Safety assembly for a tool for driving fasteners |
| DE3020286A1 (en) * | 1980-05-28 | 1981-12-03 | Hilti AG, 9494 Schaan | INTERNAL POWERED SETTING DEVICE |
| GB2117692B (en) * | 1982-02-11 | 1985-01-23 | Black & Decker Inc | Latching arrangement for a power-driven tacker |
| US4629106A (en) * | 1985-05-29 | 1986-12-16 | Signode Corporation | Actuating means for fastener driving tool |
| DE3703753A1 (en) * | 1987-02-07 | 1988-08-18 | Haubold Kihlberg Gmbh | Driving-in device (tacker) for fastening means having a triggering safety device |
| DE8810753U1 (en) * | 1988-08-25 | 1988-10-20 | Joh. Friedrich Behrens AG, 2070 Ahrensburg | Fastener driver |
| DE8914926U1 (en) * | 1989-12-19 | 1990-02-01 | Joh. Friedrich Behrens AG, 2070 Ahrensburg | Trigger-protected fastener driver |
-
1991
- 1991-05-14 CA CA 2042497 patent/CA2042497A1/en not_active Abandoned
- 1991-05-14 AU AU77046/91A patent/AU7704691A/en not_active Abandoned
- 1991-05-15 EP EP91107871A patent/EP0457305A1/en not_active Withdrawn
- 1991-05-15 JP JP22822991A patent/JPH0679649A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| AU7704691A (en) | 1991-11-21 |
| JPH0679649A (en) | 1994-03-22 |
| EP0457305A1 (en) | 1991-11-21 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |