US2555995A - Two-speed driving tool - Google Patents

Description

June 5, 1951 H. A. PlTzER, JR 2,555,995

Two-SPEED DRIVING TooL l Filed Jan. 13, 195o 2 sheets-sheet 1 A ...nl AAAAAA AA f n.. Al-an..

A Morin/y H A PlTzER, JR 2,555,995

TWO-SPEED DRIVING'TOOL 2 Sheets-Sheet 2 L11/enzo# I rr/,Pz@2z dr. )1. v Allorm'y June 5, 1951 Filed Jan. 13, 1950 Patented .une 14951 UNITED STATES PATENT OFFICE TWO-SPEED DRIVING TOOL Harry A. Pitzer, Jr., Cumberland, Md.

Application January 13, 1950, Serial No. 138,393

(Cl. 'Z4- 130) 1 claim. l

' This invention relates to a novel construction of driving tool for use with screwdriver bits, drill bits or other bits which are actuated by being rotated on their longitudinal axis, and has for its primary object to provide a novel construction of tool whereby a bit will be revolved on its longitudinal axis by a force exerted on the tool in a direction axially thereof and of the tool bit.

More particularly, it is an aim of the present invention to provide a tool which may be readily adjusted for varying the speed at which the tool bit will be revolved relatively to the speed of sliding movement of the actuating means relatively to the tool bit for adapting the tool to Work requiring different degrees of force, as for example in applying a screw to a hardwood surface and to a softer, more penetratable wood.

Still a further object of the invention is to provide a tool having means for automatically returning it to an extended position preparatory to receiving another power stroke to enable the tool to be rapidly operated by a reciprocating movement wherein force is exerted by the operator in only one direction.

,Still another object of the invention is to provide a tool having means for releasably locking the tool bit relatively to the reciprocating tool parts whereby all parts of the tool revolve in unison, thereby readily adapting the tool for use in removing a screw.

Various other objects and advantages of the invention will hereinafter become more fully apparent from the following description of the drawings, illustrating presently preferred embodiments thereof, and wherein:

Figure 1 is a side elevational view, partly in vertical section and showing the tool in a projected position;

Figure 2 isa View similar to Figure l but showing the tool in a retracted position and looking from left to right of Figure l;

Figures 3 and 4 are cross sectional views of the tool taken substantially along planes as indicated by the lines 3-3 and 4 4, respectively, of Figure 2;

Figure 5 is a plan view looking toward the inner side of a part of the tool;

Figure 6 is a cross sectional view thereof taken substantially along a plane as indicated by the line 6-46 of Figure 5;

Figure '7 is a side elevational view of another section of the tool, likewise shown removed;

Figure 8 is a cross sectional View thereof taken substantially along a plane as indicated by the line `8--J8 of Figure 7;

Figure 9 is a side elevational view of the shift lever shown removed;

Figure 10 is a fragmentary vertical sectional view, partly in side elevation of a modification of the tool of Figures 1 to 9, and

Figure ll is a cross sectional view of a modifled form of tool taken substantially along a plane as indicated by the line I i-I i of Figure 10.

Referring more specifically to the drawings, and :rst with reference to the embodiment as illustrated in Figures 1 to 9, the two speed driving tool in its entirety and which comprises the invention is designated generally I2 and includes a tubular housing or barrel I3 in one open end of which is received a cap It and the other open end of which receives the enlarged end of :a longitudinally tapered bearing I5 which extends outwardly from the last mentioned end of the housing I 3. The cap I4 and bearing I5 are detachably secured in the ends of the housing I3 each by a plurality of screw fastenings I6. The cap I4 is provided with two inwardly opening recesses 'I' and I8 and the bearing I5 has two inwardly opening recesses I9 and E@ which are in longi tudinal alignment with the recesses Il and I8, respectively. A rod 2| extends longitudinally through the housing i3 and has its ends seated in the recesses Il and Iii and a shift rod 22 likewise extends longitudinally through the housing I3 and has its ends engaging in the recesses I8 and 20 and is mounted for swivel movement therein. The ends of the rod 22 are normally spaced from the beds of the recesses I8 and 20 to permit a slight sliding movement of the rod 22 longitudinally of the housing I 3, for a, purpose which will hereinafter become apparent.

An elongated core or frame, designated generally 23, best illustrated in Figure 5- and which is substantially half circular in cross section, is detachably supported within the housing I3 and secured thereto by a screw fastening 24. The core or frame 23 extends substantially from end-toend of the housing i3 and affords a slight space between one end thereof and the cap I4 and a somewhat larger space between its opposite end and the bearing I 5, as clearly illustrated in Figures l and 2. The core 23 is provided with diametrically opposed inwardly facing channels 25 and 26 forming rails or runways, for a purpose ywhich will hereinafter become apparent. Adjacent the runway 25, the c'ore 23 is internally thickened and toothed to provide spaced rack portions 2l and 28 which are spaced different distances from the plane of the tracks 25 and 26, and said internally thickened portion is re 3 cessed between the racks 21 and 28 to provide a channel or free way '29.

A carriage, designated generally 30 and best illustrated in Figures '7 and 8 includes a frame or body portion 3| having a relatively large opening 32 in one end thereof and a longitudinally extending bore 33, one end of which opens into the opening 32 and the other end of which opens outwardly of the lower end 34 of said body member 3|. A driving tool bit 35, and herein illustrated as a screwdriver bit, has an elongated shank 36 which extends reciprocally and rotatably through a longitudinal bore 31 of the bearing I and which bore is disposed axially of the housing I3. The bore 31 preferably contains a bushing 38 in which the tool bit shank 36 is rotatably and slidably disposed.y Said tool bit shank 36 is relatively long and extends inwardly from the bearing I5 through the bore 33 and into the opening 32. A hub 36 having a socket opening outwardly of its lower end is mounted on the end of the shank 36 which is disposed in the opening 32 and for rotation relatively thereto. Said hub 39 is provided at its upper end with a beveled gear 46 and at its lower end with a clutch half Y4 I. The clutch half 4| is provided with a depending annular toothed portion all of the teeth of which are inclined in the same direction for engagement with a similar upwardly facing toothed portion of a lower clutch half 42 which is likewise disposed within the opening 32 and slidably keyed to the bit shank 36 by a key 43 thereof which engages a longitudinally extending groove 44 of said bit shank. A spring 45 is mounted on the shank 36 between the lower end of the lower clutch half 42 and the surface of the body 3| defining the lower end of the opening 32 for yieldably retaining the teeth of the clutch halves 4| and 42 in intermeshing engagement, as best illustrated in Figure '7. Between the opening 32 and the lower end 34,l the body member 3| is provided with an opening 46 through which a portion of the shank 36 extends and which contains an anti-friction thrust bearing 41 which is mounted on the shank 36 and supported by a thrust collar 48 which is adjustably secured to the shank 36 and which is likewise diss posed in the opening 46. 'The thrust bearing 41 bears against the Atop wall of the opening -46 `to provide an anti-friction support for the carriage 3|) on the bit shank 36.

Yrhe carriage 33 near its lower end is provided with transversely aligned outwardly projecting ,stub axles t9 on each of which is journaled a :roller 50. The carriage body 3| is provided near its opposite, upper end with transversely aligned bearing openings 5I for journaling a shaft 52 which extends transversely through the opening 32 above the beveled gear 40. A roller 453 is mounted on each end of the shaft 52. The complementary rollers 50 and 53 are disposed in longitudinal alignment and are spaced outwardly from the side edges of the carriage body 3| and are adapted to engage the track ways 25 and 26, asbest illustrated in Figure 3 for mounting the carriage 3Q for reciprocating movement within the housing I3 and longitudinally vthereof and of the core `23. As seen in Figure 3 the carriage 3| is provided with a laterally projecting ear154 having an opening therethrough extending 1ongitudinally of the housing I3v and through which the rod 2| slidably extends. An expansionV coil spring 55 is mounted onV the rod 2| betweenfthe cap I14 and said ear 64 for yieidably `'urging .the carriage *3U and the parts connected thereto -downwardly with respect to the housing I3 and core 23 from the projected lposition of the parts, as illustrated in Figure 1 to their retracted positions of Figure 2, so that the carriage 3|] will normally be disposed in its position of Figure 2.

A compound gear 56 is disposed in the opening 32 and slidably splined as seen at 51 in Figure 8 to the shaft 52. Said gear 56 includes a large gear portion 53 forming a ratchet wheel for engagement with the rack 21 and a smaller gear portion 66 for engagement with the rack 28 and which is spaced from the gear 59. A disk 6I is suitably secured to the enlarged end or side of the compound gear 56 and has a laterally oiset peripheral portion or ange 62 which is spaced from the gear 59. A beveled gear 63 is fixed to the shaft 52 independently of the gear 56 and is disposed in meshing engagement with the beveled gear 4B. A portion of the shift rod 22 is provided with a laterally extending web 64, the outer longitudinal edgeY of which engages between a portion of the gear 59 and the vflange 62 so that by turning the shift rod 22 the compound gear 5S may be displaced longitudinally of the shaft 52 for positioning either the gearv 53 in engagement with the rack 21 or the gear 6|) in engagement with the rack 28, The free way 29 is provided to accommodate the gear 59 when the gear 60 is in meshing engagement with the rack 28'.

The shift rod 22 is provided nearits lower end with a shift lever 65 which is fixed thereto and which projects outwardly through a slot 66 in the housing I3 and adjacent the lower end thereof and by means of which the shift rod 22 may be turned on its longitudinal axis for `positioning either the gear 59 or the gear 60 in a meshed position, as previously described.

In the embodiment as illustrated in Figures 41 to 9, a flanged collar` 61 is loosely disposed on the tool bit 35 and seats against the inner end of the bearing l5. The bit shank 36 is provided with a relatively long spline or groove 68 for receiving a key 69 which projects into the bore of alocking disk 1U which is disposed on the shank 36 ,and rests against the upper end of the hanged collar 61 for slidably keying said disk 1.0 to the shank 36. A locking lever 1I is swingably mounted at one end thereofV on the shift rod 2 2 above nthe shift lever 65 and extends substantially ,diainetriV outwardly of the periphery of the disk 10, irl-one position of Vthe lever 1|. VA'Dlate `16 is provided with openings for ,loosely receiving' .the rods 21 and 22 and the tool bit 36 and rests .uponzthe pivoted end ofthe lever 1I, as seen in'Figure121and holds :said lever Y'III against upward vdisplacement on `they shift rod 22, on which it is turnably dis.-

posed. The plate 16 is in turn held against .up-'-V ward displacement by-a cellar 1:1 whichis1seciired to the shift rod 22 and which hearspn the -plate 1.6. Arcollar Ellis iixed tothe shift rod 22adjacent-its `upper ,end and has a coil spring :19 hearing thereon and which likewise bears againstv the .cap |4 for Iurging plate 16.

Assuming .the parts Vof the -tcol I2 Lto be in the positions:asillustratedzin .Figure 2 :and assuming the collar ,11 Vagainst fthe that the bit 35 is engaging a screwfkeribyeiert ing a force against the cap I4 toward the bit 35, the housing I3 together' with the core 23, cap I4 and bearing I5 `will move relatively to the carriage 3d and bit shank te toward the bit and in so moving, the gear 5@ by meshing engagement with the rack 2T will be revolved in the direction as indicated by the arrows thereon in Figure 2 for turning the shai't 52 and beveled gears G3 in the same direction to cause the beveled gear 4B and the shank 3E to be revolved in the direction as indicated by the arrow in Figure 2 applied to the gear 40 for exerting a torsional force on the screw engaged by the bit 35 for embedding it in an element. It will be apparent that the inclined disposition of the teeth of the clutch halves 4I and 42 will retain the clutch halves in locked engagement when the beveled gear It is thus revolved so that bit shank 36 Will turn therewith. When the longitudinal force is released from the cap lli, the compressed spring 55 will return the parts to their retracted positions of Figure 2 by forcing the carriage toward the bearing I5 and the bit shank 3b will be carried with said carriage and will slide through said bearing I5, During this movement, the gear 59, shaft 52 and gear E3 will be revolved in the opposite direction to turn the gear di! in the opposite direction but the bit shank 36 will not be revolved with the gear 4t in this reverse direction due to the fact that the teeth of the upper clutch half 4I will ride over the teeth of the lower clutch half which will be cammed downwardly thereby against the action of the spring 45 to allow the hub 39 and its clutch half 4I to turn relatively to the clutch half i2 and -bit shank 36. By turning the shift rod 22 clockwise as seen in Fig-ure 3 by manual operation of the lever t5, the web 64 thereof will shift the compound gear 5t to the right of its position of Figure 3 to position the gear 6E] to mesh with the rack 2d and the gear 59 out of mesh with the rack 2l thereby placing the tool I 2 in a geared position for high speed operation and wherein the shaft 52 will be revolved more rapidly in ratio to the translational motion of the housing I 3 for revolving the bit 35 at a greater speed and to cause it to make a greater number of revolutions in the movement of the parts from their positions of Figure 2 to their positions of Figure 1. Accordingly, the tool can be used in this last mentioned high speed position Where a screw, not shown, is being driven into soft wood, for example, and in its low speed position as illustrated in Figures 2 and 3 where a screw is to be driven into hardwood or where greater torsional force is required. When it is desired to utilize the tool I2 for extracting a screw, the locking lever 'il is manually swung counterclockwise as seen in Figure fl to engage the stud 'I4 with one of the notches 'i5 to prevent the disk 'IU and bit 35 from turning relatively to the housing I3 and bearing I5 so that the tool may then function as a conventional screwdriver.

Obviously, other types of turning tool bits such as drill bits could be substituted for the screwdriver bit 35.

Figures 10 and 11 illustrate a modied means for mounting the locking disk and locking lever, requiring fewer parts and wherein the flanged collar 5l is omitted and the locking disk 'Illa rests instead on a washer Bla which bears on the inner end of the bearing I5a. The locking lever "IIa, which is of a slightly modified shape is swingably mounted at one end thereof on the rod 2|a rather than on the shift rod 22a and instead of the shift rod 22a being provided with a collar 18 and a spring "i9, the collar '18a is adjustably secured to the rod 2id above and adjacent the plate '15a and the spring 79a is disposed on the rod 2 la between said collar 78a and the plate 16a so that the levers (55a and 'ila are disposed in the same plane and the plate 'Ilia is held down at each of its ends by the spring 59a and the collar lia. If desired, the shift rod 22d may likewise be provided with a collar and spring, corresponding to the collar 'i3 and spring 'I9 so that the plate ita will be yieldably urged downwardly at each end thereof. As the function of the parts shown in the modification of Figures l0 and 11 are the same as the complementary parts illustrated in Figures 1 to 9, a further description thereof is considered unnecessary.

Various other modifications and changes are contemplated and may obviously be resorted to, without departing from the spirit or scope of the invention as hereinafter dened by the appended claim.

I claim as my invention:

A thrust actuated turning tool comprising an elongated housing, an elongated bit shank slidably and rotatably disposed in said housing and projecting axially from one end thereof, a stationary rack in the housing, a carriage reciprocally mounted for longitudinal movement in the housing in which one end of the bit shank is nonslidably journaled, a shaft journaled in said carriage, a gear forming a ratchet wheel keyed to the shaft and meshing with said rack, beveled gear means connecting said shaft and bit shank, and spring means yieldably urging the carriage toward one end of the housing for normally holding the housing in a retracted position with respect to the bit shank, said housing being movable against the action of said spring relatively to the bit shank and carriage by a thrust exerted axially thereon for displacing the carriage and bit shank longitudinally toward the end of the housing, opposite to the end in which the bit shank is journaled, for causing the ratchet wheel to be revolved by engagement with said rack for revolving the bit shank, a second, smaller ratchet wheel mounted on said shaft, said ratchet wheels being slidably keyed to the shaft for movement as a unit relatively thereto, a second rack for engaging the second ratchet wheel when the iirst ratchet wheel is displaced out of engagement with the first rack, and manually actuated shift means including a rod journaled in the housing for rotating about its longitudinal axis and relative to which the carriage is slidably movable for displacing the ratchet wheels as a unit relatively to the shaft for positioning one or the other of the ratchet wheels in engagement with its respective rack to vary the speed of rotation of the bit shank relatively to the speed of sliding movement of the bit shank with respect to said housing.

HARRY A. PITZER. J R.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date Re. 11,272 Crowell Sept. 27, 1892 452,617 Satterlee May 19, 1891 873,296 Chappelle Dec. 10, 1907

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