US2850736A - Fastener inserting devices - Google Patents

Description

Sept.9, 1958 w. M. HOUGHTON .FASTENER INSERTING DEVICES 4 Sheets-Sheet 1 Filed July 26, 1956 m w y {w i mM w Vz W .IWB. m 1 k M 0 0 fl w 5 $2 2 w, H W a H F A W w .6 0 p} .m M A g//k la f! W. M. HOUGHTON FASTENER INSERTING DEVICES Sept; 9; 1958 4 Sheets-Sheet 2 Filed July 26, 1956 Inventor William MHoug/norz P 9, 1953 w. M. HOUGHTON 2,850,736 FASTENER INSERTING DEVICES Filed July 26, 1956 4 Sheets-Sheet 5 t Inventor W'Zliam M Houghfon B e5 Sept. 9, 1958 Filed July 26, 1956 W. M. HOUGHTON FASTENER INSERTING DEVICES 4 Sh eets-Sh eet 4 Inventor W/z'lliam .MHou ghzon By his z I 2 e3 United States Patent FASTENER INSERTING DEVICES.

William M. Houghton, Marblehead, Mass., assignor to United Shoe Machinery Corporation, Flemington, N. J., a corporation of New Jersey Application July 26, 1956, Serial No. 600,326

Claims. (Cl. 1-1) anism which automatically orients and feeds fasteners one at a time upon receipt of a signal emanating from the tool. Generally, there are three lines or conduits attached to the driving tool. The first is a fiuid supply line, and since these tools are usually operated by compressed air, the supply line is an airtight conduit. The second line is a fastener delivery tube through which fasteners are propelled from the feeding mechanism and the third is a signal line to transmit a pneumatic signal to the feeding mechanism to deliver a fastener. dom of movement of the driving tool are important factors influencing operator fatigue and consequently his production, thus an obvious advantage results from reducing the weight and increasing freedom of movement by eliminating one or more of the lines attached to the tool.

An object, therefore, of this invention is to provide a fastener inserting device having a light weight portable driving tool with a minimum of separate lines or conduits attached thereto.

Attempts have been made to combine the air supply line and the fastener delivery tube in a single conduit but this requires complex valve mechanism on the driving tool which adds to, rather than subtracts from, its weight. However, since the signal line must also be connected to the driving tool by an appropriate valve, the elimination of the signal line obviates the necessity for this valve and thereby not only reduces the weight of the tool but its cost as well.

Another object of this invention, therefore, is to provide a fluid-operated fastener inserting device having an automatic feeding mechanism and a portable driving tool which device does not require a separate signal line connecting the driving tool to the feeding mechanism.

Because the rate of operation of thedriving tool is determined for the most part by the nature of the work, the rate of fastener consumption is not always constant but more often is irregular or intermittent. Thus, the feeding rate cannot be maintained constant but must be responsive to the requirements of the tool, otherwise a fastener could reach the tool before the preceding one has been inserted and jamming might result. However, to assure that no unnecessary delay takes place between driving cycles, the feeding mechanism should be actuated in timed sequence with the operation of the driving tool, and preferably in immediate response thereto.

Accordingly, it is still another object of this invention to provide a fastener inserting device having a feeding mechanism connected to a remote portable driving tool which device does not require a separate signal line but which has means for detecting accurately each driving cycle and for actuating the feeding mechanism to feed a fastener in immediate response thereto.

Some of the more frequently used driving tools of the Theweight and free- I M 2,850,736 Patented Sept. 9, 1958 portable pneumatic type are single or multiple blow nail drivers and rotary screw drivers, etc., whichvare connected by means of supply lines to substantially constant pressure sources of compressed air, such as, large capacity storage tanks or factory air systems. Each time one of these tools is operated to insert a fastener it consumes a quantity of compressed air resulting in a flow of air through the supply line. Applicant has found that by the use of appropriate flow detection mechanism in the supply line it is possible to determine with extreme accuracy when the driving operation of the driving tool begins and when it ceases. Furthermore, by triggering the feeding mechanism by the flow detection mechanism a fastener may be delivered in response to the operation of the driving tool without the need for a separate signal line.

In accordance with the above objects and as a feature of this invention there is provided a fluid operated fastener inserting device having a light weight portable driving tool-connected to a remotely located feeding mechanism with a flow responsive valve positioned in a line which supplies compressed fluid to operate the driving tool, the valve being operable to detect fluid flow in the line caused by the operation of the tool, and in response thereto, toactuate the feeding mechanism to supply a fastener to the driving tool.

The above and other features of the invention including various novel details of construction and combination'of parts will now be more particularly described with reference to the accompanying drawings and pointed out in the claims.

In the drawings,

Fig. 1 is a side elevation of a device embodying the invention for aligning fasteners with respect to their ends and for feeding them one at a time under pressure through a delivery conduit to a remotely located portable driving tool;

Fig. 2 is a vertical section through a flow responsive valve used to actuate the feeding mechanism shown in Fig. 1; i

Fig. 3 is a plan view partly in section of a portion ofthe feeding mechanism shown in Fi 1 for separating a singlefastener, transferring it to a delivery conduit and propelling it therethrough; under pressure. to the in-v serting tool;

Fig. 4 is a side elevation partly in section of the mech: anism shown in Fig. 3; and

Figs. 5 and 6 are diagrammatical views of the device shown in Fig. 1 including its pneumatic circuit, Fig.5 showing the apparatus as employed with a single-blow nail driving gun and Fig.6 showing it as employed with a rotary screw driver.

Applicants flow responsive valve may be used incombination with any pneumatically operated fastener feeding mechanism and driving tool. By way of example only, it is herein illustrated in combination with a totally pneumatic type fastener separating and feeding mechanism identical to that disclosed in an application for United States Letters Patent Serial No. 550,324, filed December- 1, 1955 in the name of Donald B. Mcllvin et al. The McIlvin device, hereinafter referred to also as the feeder.- separator, is best seen in Fig. 1 and comprises a hopper.

10 for holding a supply of randomly orientedfasteners,

such as nails or screws. The hopper is secured to a main frame 12 which may be mounted on a bench or other suitable support. Forming one side of the hopper,

is an elevating mechanism for, lifting fasteners :from the hopper and delivering them to a downwardly inclined, slotted raceway 14 along which the fasteners slide in uniformly alined relationship suspended by their heads, The elevating mechanism comprises. a plurality of liftslides 16 connected by a piston rod,18. to an air motor 11! which is controlled by a valve 22 for reciprocating the slides. Associated with the raceway 14, which is adjustable widthwise to accommodate various types and sizes of fasteners, is a rotary rejector 24 to expel any misalined fasteners from the raceway. Secured to the frame 12 and mounted on the lower end of the downwardly inclined raceway 14 is a separating and feeding element 34 which separates the endmost fastener from those in the raceway and feeds it under pressure through a delivery tube 36 to a driving tool, such as a pneumatic nail or screw driving gun, not shown in Fig. 1. The separating and feeding element 34 is pneumatically operated, being connected to the same source of pressurized air as are the driving tool and the motor 20 which operates the lift slides 16. A flow responsive control valve 38 is mounted on the frame 12 in any convenient position and is connected to the feeding and separating element 34 and the driving tool as shown in Figs. and 6 as described in detail hereinafter.

The flow responsive valve 38 is best seen in Fig. 2 and has a valve casing 40 of irregular configuration which forms a valve chamber. In one end of the casing 40 is a cylinder 42 in which slides a piston 44. The piston normally is urged byacompression spring 46 to a first position against an internal shoulder 48 formed in the casing 40. The spring 46 fits within an annular recess 50 in the piston 44 and around a collar 52 formed on a plug 54 which is secured to the casing 40 by screws 55, only one of which is seen in Fig. 2. The plug 54 forms an airtight seal on one end of the cylinder 42. On the end of the piston 44 remote from the plug 54 there is an annular chamfered area 56. Extending lengthwise through the piston 44 are a small diameter or restricted passageway 58 and the stem 59 of a control valve having the form of a spool valve 60. The valve 60 is movable relative to the piston 44 and is urged to the left relative to the piston, as seen in Fig. 2, by means of a light spring 62 compressed between the piston and a collar 64 fixed to the stem 59. In the upper portion of the casing 40 is threaded an air inlet fitting 66 to provide an inlet opening from an air supply line 68 to a main chamber 70 forming part of the valve chamber within the casing 40. The main chamber 70 communicates with the open end of the cylinder 42 and by means of the restricted passageway 58, with a chamber 72 comprising the closed end of the cylinder 42 which is the portion of the cylinder located on the left-hand side of the piston 44. Threaded in a lower part of the casing 40 is a fitting 74 to provide an exit opening between an air line 76 and an exit chamber 78 which communicates with the chamber 72 of the cylinder 42 by means of interconnecting small diameter passageways 80 and 82 formed in the casing 40 and the plug 54 respectively. A port 84 connects the chamber 78 directly with the cylinder 42.

The spool valve 60 comprises the above-mentioned stem 59, a flange 85 and a pair of spools 86 and 88. The spools 86 and 88 are provided with 0 rings of conventional type to form airtight seals with a cylinder 90 in which the valve 60 is slidable. One end of the cylinder 90 communicates directly with the main chamber 70 and the opposite end communicates with a passageway 92 connected to the main chamber 70. Enclosing the righthand end of the cylinder 90 and the passageway 92 is a cap 94 secured to the casing 40 by screws 96, only one of which is seen in Fig. 2. Threaded in the casing 40 is a fitting 98 to provide a connection between an air line 100 and a passageway 102 which is a secondary exit opening communicating with the cylinder 90. Also threaded in the casing 40 is still another fitting 104 forming a connection between an air line 106 and a chamber 108 which communicates with the cylinder 90 by means of a passageway 110. The passageway 110, which may be considered another secondary exit opening, bypasses anddoes not communicate directly with the passage- W91 The flow responsive valve 38 operates in the following manner. The air supply line 68 is connected to a substantially constant pressure source of compressed air, thus pressurizing the main chamber 70 by means of the air inlet 66 and the chamber 72 by way of the small diameter or restricted passageway 58 in the piston 44. By means of the passageway 82, the passageway 80, the exit chamber 78, and the air exit fitting 77, the air line 76 is also pressurized. The air line 76 is connected to any device which is to consume compressed air. When there is no flow of air through the line 76, the chamber 72 is maintained at the same pressure as the main chamber 70 and the piston 44 is maintained in its first position against the shoulder 48 by the spring 46. When air is drawn from the line 76, flow takes place through this line as well as through the exit chamber 78 and the passageways and 82. The passageway 58 is sufliciently small to restrict the flow of air to the chamber 72 to a quantity less than that which flows from the exit chamber 78 through the line 76, resulting in an immediate small pressure drop in the chambers 72 and 78. The greater air pressure then in the chamber 70, acting on the righthand face of the piston 44, causes it to be displaced to the left to a second position compressing the spring 46 and moving the valve 60 to the left therewith.

The movement of the piston 44 to the second position uncovers the port 84 leading to the exit chamber 78 whereby air then flows directly from the chamber 70 into the exit chamber 78 and the line 76. The port 84 in cooperation with the piston 44 acts as a control or throttling valve which in cooperation with the force of the spring 46 maintains the pressure in the exit chamber 78 lower than the pressure in the main chamber 70 during flow through the line 76. Fluctuations in flow through the line 76 caused, for example, by an increase or decrease in the rate of operation of the driving tool will result in fluctuations in pressure in the exit chamber 78. If the pressure in the exit chamber 78 decreases slightly because of a greater flow, more of the port 84 will be exposed by the piston 44 since the lowered pressure also in the chamber 72 will permit the pressure within the main chamber 70 'to displace the piston 44 a somewhat greater amount to the left. Conversely, a small increase in pressure in the line 76 and thus in the exit chamber 78 caused by less flow will effect a throttling action, to wit, a slight movement of the piston 44 to the right making the effective size of the port 84 somewhat smaller. Thus, the piston 44 may tend to float varying the size of the port 84 maintaining the pressure within the chamber 78 lower than the pressure in the chamber 70 during flow through the line 76.

In order to prevent any floating or oscillating motion of the piston 44 from being transmitted to the valve 60, the piston is movable, within a limited range relative to thevalve. The above-mentioned 0 rings in the spools 86 and 88 maintain a sufiiciently close fit with the cylinder to prevent the valve 60 from moving as a result of slight movement of the piston 44. Any floating or oscillating motion of the piston 44 causes the spring 62 to become compressed or expanded to a greater or lesser degree but the force of the spring 62 alone is insutficient to move the valve 60 relative to the cylinder 90. Thevalve friction does not impede the floating action of the piston 44.

The initial displacement of the piston 44 to the left, to the second position as stated above, moves the valve 60 to the left, the piston abutting the collar 64 on the valve. This movement positions the spool 88 to the left of thc secondary exit opening 102 placing the line in communication with the pressurized passageway 92 to permit air to flow through the line 100 for purposes. such as actuating a feeder-separator, as hereinafter to be described.

When the flow through the line 76 stops, the chambers 78 and 72 again become pressurized at the same pressure its right-hand position against the shoulder 48 by the spring 46. The valve 60 is moved to the right by the piston 44 engaging the collar 85, the spool 88 shutting off the line 100 from the pressurized passageway 92-and placing the line 100 in communication with the line 106 through the passageway 162, the cylinder 90, the secondary exit opening 110 and the chamber 108. Whether the line 106 is employed or the chamber 108 closed by a plug is determined by the use to which the flow responsive valve 38 is placed as will become more evident hereinafter.

The separating and feeding element 34 will now be described briefly. For a more detailed explanation of its structure and operation the above-mentioned Mcllvin application may be referred to. Referring to Fig. 4, there is provided a presser foot 120 of rubber or similar material arranged to be moved toward and away from the lower end of the raceway 14 to engage and then release the heads of fasteners, herein illustrated as screws, as they slide down the raceway. The presser foot 120 is urged downwardly toward the raceway by means of a spring 122 and is movable away from the raceway by an air operated piston 124 mounted within a cylinder 126. The air for elevating the piston 124 and hence the presser foot 120 is supplied through a conduit 128 attached to a fittting 129 threaded in the cylinder 126. As seen in Fig. 4, the lower end of the raceway 14, all of which slopes downwardly (see Fig. 1), is further sloped along a portion 130 substantially parallel to the bottom of the presser foot 120'. The portion 130 terminates abruptly exposing a fastener receiving area 132 extending beyond the presser footand spaced slightly below the portion 130. When the presser foot is elevated, the endmost fastener is released onto the receiving area 132, its shank engaging the closed wall of a sleeve 134 which is rotatably mounted within a housing 136. The'lower end of the sleeve is attached to the flexible delivery conduit 36 for conducting fasteners to the inserting tool. Rotary motion is imparted to the sleeve 134 by means of a slidable rack 140 (Fig. 3) which engages a pinion 142 secured to the top of the sleeve 134. In one position of rotation a slot 144 in the sleeve 134 faces the receiving area 132 and in another position of rotation faces a fitting 146 (Fig. 4) threaded into the housing 136 and connected to an air line 150. The rack 140 is attached to a piston 152 slidable within a cylinder 154 which forms the upper portion of the housing 136. On one end of the piston 152 is a head 156 and on the opposite end is a head 158 separated from the main portion of the piston by a necked area 160. A cap 161 closes one end of the cylinder 154 and an air inlet fitting 162 is threaded in a cap 164 secured to the opposite end of the cylinder 154. Through the fitting 162high pressure air is admitted into the cylinder 154 to displace the piston in a downward direction as viewed in Fig. 3 to rotate the sleeve 134. In the lower end, Fig. 3, of the cylinder 154 is threaded a fitting 168 to which is connected an air line 170 which communicates with a constant pressure source of compressed air. Also threaded in the cylinder 154 is a fitting 172 which is in the form of a T connection having one end connected to the fitting 129 in the presser foot cylinder 126 by means of the line 128. The other branch of the T is connected to the fitting 146 by means of the conduit 150. The piston 152 and consequently the sleeve 134 are normally maintained by air pressure acting against the head 158 in the positions shown in Figs. 3 and 4 with the slot 144 in the sleeve facing the receiving area 132. The presser foot 120 is held downwardly by the spring 122 against the heads of fasteners located on the sloped portion 130 of the. raceway 14. When a blast of air is admitted through the fitting 162 to the upper end of the cylinder 154, as seen in Fig. 3, the piston 152 moves downwardly, the head 156, being of greater diameter than the head 158, displacing the rack 140 which causes the sleeve to be rotated to a position wherein the slot 144. faces the air inlet fitting 146 and the closed wall faces the receiving area 132. The piston head 158 moves toward the cap 161 permitting the pressurized air in the line 170 to flow into the lower end of the cylinder 154, past the necked area 160 and into the T fitting 172. A portion of this air passes through the conduit 128 into the cylinder 126 and elevates the presser foot 120, permitting the endmost fastener to fall onto the receiving area 132 with its shank against the then closed wall of the sleeve 134. Another portion of the air also passes from the T fitting 172 through the line 150 and enters the sleeve 134 through the slot 144 which has become alined with the fitting 146. The fastener which entered the sleeve and fellinto the conduit 36 during the preceding operating cycle is propelled by this air blast to the inserting tool.

Upon the release of pressure in the fitting 162 the piston 152 is returned to its upper position as seen in Fig. 3 by the air pressure on the lower face of the head 158, the air above the piston head 156 escaping through a bleeder valve 186 (Figs. 5 and 6). The pressure in the line 128 is reduced and the presser foot 120 descends under the force of the spring 122 into engagement with the heads of fasteners located on the sloped area 130. The sleeve 134 is rotated whereby its slot 144 again faces the receiving area 132 and the fastener then located thereon falls through the slot 144 downwardly into the conduit 36 coming to rest at a bend therein ready to be propelled to the inserting gun during'the next operating cycles It will be;noted that the above described Mcllvin feeding mechanism is operated by a blast of air entering the cylinder 154 through a fitting 162 and by the constant pressure in the line 170, no other operating mechanis being required.

The more common portable pneumatic inserting devices may be classified in two general categories, 1)

those in which the actual fastener driving operation is substantially instantaneous, for example, a single-blow.

nail or tack driver, and (2) those in which the driving operation requires a somewhat longer or sustained period of time, for example, multiple-blow nail drivers and rotary screw drivers. Feeding mechanisms used with the tools in the first category may deliver the next fastener immediately upon the 'tool being fired since the tools driving periods are sufiiciently short so as to be completed before the next fastener can be propelled through the delivery conduit thereby substantially eliminating the possibility of avjam at the tool. However, with tools of the second category having longer or sustained driving periods, the actual feeding of a subsequent fastener must be delayed until the driving operation ceases otherwise a jam will occur at the inserting tool.

a The operation of the fastener inserting device employing applicants flow responsive valve 38 for supplying fasteners to'tools having a sustained driving period, herein illustrated as a pneumatically operated rotary screw driver, will now be described with reference "to Fig. 6. The screw driver 188 is of a well-known commercial type, not shown in detail, in which a screw is rotatably driven by means of a pneumatic motor actuated by a trigger 182. The compressed air for operating the gun comes from the line 76 which is attached to the fitting 74 threaded in the casing 40 of the flow responsive valve 38. The line which is attached to the fitting 98 in the flow responsive valve is connected to an air accumulator 184 which is part of the feeder-separator or feeding mechanism. The line 68 which is attached to the fitting66 in the flow responsive valve is connected to a constant pressuresource of compressed air. The combination of lines- 68 and 76 through which air flows to the inserting tool mayalso be referred to as thefirst line for the purpose of this invention. The line 106 which is attached to the, fitting 104 of the flow responsive valve is attached to the upper end of the cylinder 154 by means of the 7 fitting 162. The lines 100 and 106 may be considered the second line for the purposm of this invention.

When the trigger 182 of the screw driver 180 is depressed, air flows through the line 76 to operate the screw driver. This flow, as stated above, causes the piston 44 of the flow responsive valve 38 to move to the left wherein the control or spool valve 60 is moved to a position wherein the pressurized air in the main chamber 70 may flow by means of the passageway 92, through the line 100 into the air accumulator 184. During this time, the air within the line 106 connected to the cylinder 154 of the feeder-separator remains at atmospheric pressure and the feeder-separator is not actuated. Releasing the trigger 182 of the screw driver after a screw has been driven cuts off the flow of air through the line 76 permitting the air in the chamber 72 again to reach the same pressure as that in the main chamber 70, the piston 44 and the spool valve 60 again moving to their right-hand positions. At this time, the line 100 is placed in communication with the line 106 by means of the passageway 110 and the compressed air within the accumulator 184 flows into the line 106. The pressurized air in the line 106 upon reaching the cylinder 154 of the separating and feeding element 34 displaces the piston 152 to actuate the element 34 in the manner described briefly above and in more detail in the above-mentioned McIlvin et al. application, whereby a fastener is propelled through the conduit36 to the screw driver.

An alternative method of supplying fasteners to a substantially instantaneously operated inserting tool illustrated as a single-blow nail driver will now be described with reference to Fig. 5. The inserting gun 188 illustrated in Fig. is identical with that disclosed in an application for United States Letters Patent Serial No. 535,365, filed September 20, 1955, in the names of Fred F. Chellis et al. Without describing the gun in detail it is suflicient to say that a nail is driven from the nosepiece 190 thereof when the gun is pressed against a work piece. The gun is operated pneumatically, being connected to the line 76 leading from the flow responsive valve 38. In the same manner as the screw driver, the operation of the gun 188 causes a flow through the line 76 but because the driving operation is almost instantaneous it is unnecessary to delay the feeding of the next fastener. Accordingly, it is not necessary to employ an air accumulator as part of the feeding mechanism, such as the accumulator 184 illustrated in Fig. 6. The line 100, now alone considered the second line, is connected directly to the cylinder 154 and the fitting 104 threaded in the flow responsive valve casing 40 is replaced by a plug 192. Accordingly, when the piston 44 of the flow responsive valve is displaced by the pressure in the main chamber 70, compressed air flows through the passageway 92 into the line 100 directly to the cylinder 154 of the feeding element 34 causing it to operate immediately as above described. Upon release of the nail driving gun 188 from the work piece, its nosepiece 190 is returned to its original position as explained in the above-mentioned Chellis et al. application and the line 76 again reaches full line pressure, the piston 44 of the flow responsive valve returning to its right-hand position as shown in Figs. 2 and 5, ready for another operating cycle.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

l. A fastener inserting device having, in combination, a fluid operated driving tool, a line connected to the driving tool for supplying operating fluid thereto, means for feeding fasteners to said driving tool, and means in said line operative in response to the flow of fluid therethrough for controlling the operation of said feeding means.

2. A fastener inserting device having, in combination, a fluid operated driving tool, a line connected to the driving tool for supplying operating fluid thereto, means for feeding fasteners to said driving tool, and fluid responsive means in said line forcausing operation of said feeding means in timed relation to the operation of said driving tool.

3. A fastener inserting device having, in combination, a fluid operated driving tool, a line connected to the driving tool for supplying operating fluid thereto, means for feeding fasteners to said driving tool, a member interposed in said line movable from a first position to a second position in response to flow of fluid through said line, means acting on said member to maintain it in the first position when there is no flow through said line, and means controlled by the movement of said member for causing operation of said feeding means in timed relation to the operation of said driving tool.

4. A fastener inserting device having, in combination, a fluid operated driving tool, a line connected to the driving tool for supplying operating fluid thereto, fluid pressure means for feeding fasteners to said driving tool, a valve for controlling the operation of said fluid pressure means, and flow responsive means in said line for moving said valve to operate said fluid pressure means in timed relation to the operation of said driving tool.

5. A fastener inserting device having; in combination, a fluid operated driving tool, a line connected to the driving tool for supplying operating fluid thereto, means for feeding fasteners to the driving tool, a flow responsive valve interposed in said line, a piston in said valve movable from a first to a second position in response to flow of fluid through said line, resilient means acting on said piston to maintain it in the first position when there is no flow through said line, and means controlled by the movement of said piston for causing operation of said feeding means in timed relation to the operation of said driving tool.

6. A fastener inserting device having, in combination, a fluid operated driving tool, fluid pressure means for feeding fasteners to the driving tool, a flow responsive valve, a first line connecting said valve to the driving tool for supplying operating fluid thereto, a second line connecting said valve to the feeding means for supplying operating fluid thereto, a supply line connecting said valve to a source of pressurized fluid, a chamber within said valve communicating with the supply line, a piston within said valve movable in response to a flow of fluid from said chamber through the first line, and a control member movable with said piston to permit fluid to flow from said chamber through the second line to the feeding means only when flow takes place from the chamber through the first line.

7. A fastener inserting device having, in combination, a fluid operated driving tool, fluid pressure means for feeding fasteners to the driving tool, a flow responsive valve, 2. first line connecting said valve to the driving tool for supplying operating fluid thereto, a second line connecting said valve to the feeding means for supplying operating fluid thereto, a supply line connecting said valve to a source of pressurized fluid, a chamber within said valve in open communication with the supply line, a piston within said valve movable in response to a flow of fluid from said chamber to the first line, a passageway from said chamber to the second line, and means for controlling flow of fluid through said passageway, said means for controlling being movable with said piston to permit fluid to flow from said chamber through the second line to the feeding means only when flow takes place from the chamber through the first line.

8. A fastener inserting device having, in combination, a fluid operated driving tool, fluid pressure means for feeding fasteners to the driving tool, said feeding means comprising a fastener handling mechanism and a fluid accumulator, a flow responsive valve, a first line connecting said valve to the driving tool for supplying operating fluid thereto, a second line passing through said valve and. connecting the fastener handling mechanism to the fluid accumulator, a supply line connecting said valve to a source of pressurized fluid, a chamber within said valve in open communication with the supply line, a piston within said valve movable in response to a flow of fluid from said chamber to said first line, and a control member movable with said piston to permit fluid to flow from said chamber through said second line to the accumulator only when flow takes place from said chamber to said first line and to permit fluid in the accumulator to flow through said second line to the fastener handling mechanism only after the flow from said chamber to the first line terminates.

9. A fastener'inserting device having, in combination, a fluid operated driving tool, a fluid pressure means for feeding fasteners to the driving tool, said feeding means comprising a fastener handling mechanism and a fluid accumulator, a flow responsive valve, a first line connecting said valve to the driving tool for supplying operating fluid thereto, a second line passing through said valve and connecting the fastener handling mechanism to the fluid accumulator, a supply line connecting said valve to a source of pressurized fluid, a chamber within said valve in open communication with the supply line, a piston within said valve movable in response to a flow of fluid from said chamber to said first line, a passageway from said chamber to the second line and a spool valve for controlling flow of fluid through said passageway and through said second line, said spool valve being movable with the piston to permit fluid to flow from said chamber through said second line to the accumulator only when flow takes place from said chamber to the first line and to permit fluid in the accumulator to flow through said second line to the fastener handling mechanism only after the flow from said chamber to said first line terminates,

10. A flow responsive valve comprising a valve casing having an inlet opening adapted to be connected to a source of pressurized fluid and first and second exit openings, the first exit opening being at all times in communication with the inlet opening, means normally restricting the flow of fluid from the inlet opening to the first exit opening comprising a piston having a restricted passageway therethrough, means normally maintaining said piston in a position in which fluid must pass through said restricted passageway to the first exit opening, means responsive to movement of said piston for permitting direct flow from the inlet opening to the first exit opening, one face of said piston being exposed to the pressure of the fluid at said inlet opening and the other face being exposed to the pressure of the fluid at said first exit opening, said piston being movable in a direction to permit direct flow from the inlet opening to the first exit opening in response to a drop in pressure on the face exposed to the first exit opening occasioned by a flow of fluid through said first exit opening, valve means movable with said piston for controlling the flow of fluid through said second exit opening, and means to permit limited relative movement between the piston and said valve means whereby only a substantial movement of the piston results in movement of said valve means.

References Cited in the file of this patent UNITED STATES PATENTS 984,510 Currie Feb. 14, 1911 1,885,363 Leitner Nov. 1, 1932 2,086,236 Peo July 6, 1937 2,732,554 Knott Jan. 31, 19 56

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