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Publication numberUS3187865 A
Publication typeGrant
Publication dateJun 8, 1965
Filing dateDec 21, 1962
Priority dateDec 21, 1962
Publication numberUS 3187865 A, US 3187865A, US-A-3187865, US3187865 A, US3187865A
InventorsBlachowski John A
Original AssigneeSkil Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Predetermined torque release tool with non-ratcheting feature
US 3187865 A
Abstract  available in
Images(4)
Previous page
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Claims  available in
Description  (OCR text may contain errors)

June 1965 J. A. BLACHOWSKI 3,187,865

' PREDETERMINED TORQUE RELEASE TOOL WITH NON-RATCHETING FEATURE Filed Dec. 21, 1962 4 Sheets-Sheet 1 INVENTOR. JOHN A. BLACHOWSK/ W4- Wan/Jaw ATTORNEYS June 8, 1965 J. A. BLACHOWSKI PREDETERMINED TORQUE RELEASE TOOL WITH NON-RATCHETING FEATURE 4 Sheets-Sheet 3 Filed D60. 21, 1962 Mm m L Qx

WM A.

W QWNM NW INVENTOR. L/OH/V A. BLAC/JOWSK/ ow mm wh Q wm .mn mw vm wm Nb Wm m rm m) a hw Trm m d R mm \w 9 4 f s wv mm 1|: hm Q Q m ,1 E b n w Nm i MI 2 W 0% Q A I 7 V 1 1V 1 U m r N mk KN M mm D Q \m m\ mm @v y mwhw vvw Q \m H fiTTQQ/VEYS Tune 8, 1965 J. A. BLACHOWSKI 3,187,355

PREDETERMINED TORQ RELEASE TOOL WITH NON-RATCHE G FEATURE 4 Sheets-Sheet 4 Filed Dec. 21, 1962 W |I 25 67 l 6 5'7 INVENTOR 57 (/OHN A. BLACHOWSKI 68 BY United States Patent 3,187,865 PREDETERMINED TORQUE RELEASE TOOL WITH NON-RATCHETING FEATURE John A. Blachowski, Park Ridge, 11]., assignor to Skil Corporation, Chicago, 111., a corporation of Delaware Filed Dec. 21, 1962, Ser. No. 246,391 8 Claims. (Cl. 192-56) This invention relates to tool attachments of the type adapted to be connected to rotary power tools for driving rotary fastener elements, and more particularly to new and useful improvements for the predetermined torque release hand tool disclosed in United States Patent No. 3,020,789 to Etzkorn.

Tool attachments of the type which the above referred to Etzkorn patent is illustrative include a casing which is adapted to be engaged from the rear, as by means of a shaft projecting therein, by a power tool. Suitable mechanism is provided in the interior of the casing so that when the tool is applied to drive a rotary fastener element, such as a screw or nut, as soon as a tool driving bit connected to the tool attachment is engaged with a head of the rotary fastener and pressure or thrust is applied, a clutch is engaged and power from the power tool is transmitted to the tool attachment for driving of the rotary fastener. Driving continues until the rotary fastener is tightened to a predetermined torque. These tool attachments are of the non-ratcheting variety, i.e., when a predetermined torque value has been exceeded,

the interior driving mechanism in the tool attachment.

kicks out" or disengages so that driving torque is no longer applied to the tool bit being used with the tool attachment. By this construction the driving mechanism rotates in a free wheeling or unclutched manner .until such time as the tool attachment is disengaged from the rotary fastener being run, whereupon the driving mechanism recycles. The driving mechanism in tools of the type mentioned above includes a number of moving parts, and it is somewhat complicated in con: struction.

Accordingly, it is a primary object of the present invention to provide in a tool attachment of the class described new, improved and simplified non-ratcheting driving means.

It is a more specific object of the present invention 1 to provide in a tool attachment of the class described new and simplified means for temporarily holding a collar-like clutch member out of engagement with a driven clutch member after the predetermined torque value has been reached. a

It is an even further specific object of the present invention to provide in such a tool attachment new and improved engaging means on the collar-like clutch mem ber and the driven clutch member to effect engagement of these members in a positive manner.

These and other objects and advantages of the invention will become more apparent from the following specification wherein like numerals refer to similar parts throughout.

In the drawings:

FIG. 1 is a side elevational view showing a known type of power tool, which power tool has one embodiment of the tool attachment of the present invention threadingly engaged on the front end thereof;

FIG. 2 is an enlarged longitudinal sectional view, certain parts being shown in elevation, through the tool attachment shown in FIG. 1, the driving mechanism being shown in the condition when the tool attachment is idling and the tool bit is not in the engaged or driving position;

FIG. 3 correspondsto FIG. 2, but shows the relation- 3,187,865 Patented June 8, 1965 ship of parts of the driving mechanism when the tool bit is engaged with a screw and driven by the tool attachment;

FIG. 4 corresponds to FIG. 2, but shows the condition of the driving mechanism the instant the predetermined torque value has been exceeded and the torque control clutch kicks out; FIG. 5 corresponds to FIG. 2 but shows the condition of the driving mechanism when it is in the free wheeling or non-ratcheting condition with the tool bit still engaged with the screw;

FIG. 6 is a section taken along the line 6-6 of FIG. 2;

FIG. 7 is a section taken along the line 77 FIG. 2;

FIG. 8 is a section taken along the line 88 FIG. 7;

FIG. 9 is a section taken along the line 99 FIG. 7;

FIG. 10 is a section taken along the line 10-10 FIG. 5';

FIG. 11 is a section taken along the line 1111 FIG. 10;

FIG. 12 is a section taken along the line 1212 FIG. 5; and

FIG. 13 is a section taken along the line 1313 FIG. 12. 1

Referring to FIG. 1 of the drawings, a tool attachment, generally designed 10, representing one embodiment of the invention is shown attached to the power take-off connection of a power tool indicated generally at 12. The power tool 12, which is of known type and does not of itself form a part of the present invention, is of the electrically powered type including a pistol handgrip 13 and a trigger control switch 14. An electric conductor cord by which the electric motor of the power tool is connected to a source of electric power is designated at 15 and enters the butt end of the pistol grip 13.

The forward or working end of the power tool 12 has an adapter 16 secured thereto, which adapter is externally threaded at the exposed end thereof. The tool attachment 10 includes a casing 18 having an enlarged portion 19 at the rear end thereof, which enlarged portion is internally threaded and adapted for threading engagement with the threads of the adapter 16 (see FIG. 2). A drive shaft 20 having a hexagonal shaped driving stud 21 is rotatably mounted in a bearing assembly 21a. The drive shaft projects from the front end of the tool 12 into the rear end of the tool attachment 10 for driving of the tool attachment in a manner to be described in detail as will be explained hereinafter. Preferably, the exterior of the enlarged portion 19 of the casing is knurled as indicated in FIG. 1 to facilitate attachment and removal of the tool attachment by hand. The front end of the casing 18 includes an intured annular flange 22 which is utilized in mounting of the driving mechanism within the casing 18.

Mounted within the casing 18 of the tool attachment for'rotation and for axial shifting movement therein is a spindle 25. The forward end of the spindle 25 is slidably journaled in a bearing 26, which bearing is defined by an inturned annular flange of a sleeve member 27. As will be referred to hereinafter, the sleeve 27 forms a part of adjustment means for changing the compression of a torque control spring for varying the predetermined torque release value. The rear end of the spindle 25 is journaled for rotation and for axial shifting movement in co-axial bores of a driven clutch member 28 and a power-receiving clutch member 29, which clutch members form a torque control clutch generally designated 30. It will be realized that the spindle is not in any way attached to either the driven clutch 23 or the power-receiving clutch 29. On the contrary the spindle 25 is adapted to rotate and to shift axially with respect to both clutch members of the torque control clutch. The power-receiving clutch member 29, which has a hexshaped central axial bore 31 adapted for mating engagement with the stud 21, is rotatably mounted within the casing 18 by a ball bearing assembly 32. The balls of the assembly 32 are adapted to roll between races formed by an annular shoulder on the power-receiving member 29 and by one side of a ring 33, which ring is externally threaded for engagement with the interior threads in the enlarged portion 19 of the tool attachment casing. The driven clutch member 28 is rotatably mounted within the tool attachment casing'by a ball bearing assembly 34. The balls of the assembly 34 are adapted to roll between races formed by an annular shoulder of the driven clutch member 28 and by one side of a flat ring 36. The ring 36 is constantly urged rearwardly in the casing, or to the right as viewed in FIGS. 2-5, by a torque control spring 37. Accordingly, both clutch members of the positive clutch are held in engagement with each other and they are urged rearwardly in the casing by the torque control spring 37. I

The torque control spring 37 is stationary within the casing of the tool attachment and it is under compression at all times. The front end of the spring 37 bears against a pressure adjusting nut 38, which nut is threadingly engageable with external threads provided on the rear end of the sleeve 27. The nut is slidable but nonrotatably mounted in the casing by the provision of a longitudinally disposed groove 39 provided in the outside surface of the nut, which groove is adapted to receive an indented portion 40 of the casing 13. This construction prevents the nut 33 from turning, but allows it to move longitudinally or axially within the casing. It will be apparent that by rotating the sleeve member 27 it is possible to longitudinally adjust the position of the nut 38 and thereby adjust the degree of compression on the torque control spring 37. The sleeve 27 includes an outwardly extending annular flange 41 intermediate the length thereof, which flange is adapted to abut the inner side of the annular flange 22 of the casing 18. The forward end 'of the sleeve'27 is provided with at least. two diametrically oppositely disposed flat surfaces 4-2 for reception of a wrench or like tool for turning of the sleeve 27. The sleeve 27 is adapted to be tightened in the casing 18 by means of a jarnnut 43, which nut is adapted to abut the outside surface of the annular flange22 of the casing 18. It will be seen that by loosening the jam nut 43 followed by rotation of the sleeve 27 will produce axial shifting of the adjustment nut 38 either forward or rearwardly depending on the direction of rotation of the sleeve 27. This movement of the adjustment nut 35 changes the compression on the torque control spring 37 for varying the amount of force with which the clutch members of the torque control clutch 3t) are held together. After this adjustment has been made, the nut 38 and sleeve 27 are prevented from moving by tightening of the jam nut 43. During this adjustment the torque control spring 37,, by itsengagement with the adjustment nut 38, acts to urge the sleeve 27 outwardly or to the left as seen in FIGS. 2-5 for maintaining the annular flange 41 of the sleeve 27 in abutting engagement with the'annular flange 22 of the sleeve 18.

Returning to the torque control clutch 30, it will be seen that cammingmeans are provided fordrivingly interconnecting the driven clutch member 28 with the power-receiving clutch member 29. The preferred form of this camming means comprises three camming or bearing 'balls 45, which balls are disposed between confront ing faces of the clutch members in pockets or recesses of special construction. The balls 45 are set more than 29. Provided in the rear face of the driven clutch member 28 are six equally spaced pockets 47, which pockets are somewhat shallower than the recesses 46. Normally the driven clutch and the power-receiving clutch are in the engaged or driving position as shown in FIGS. 2, 3 and. 5. It will be seen that when the torque is applied to the power-receiving clutch member and transmitted to the driven clutch member by means of the balls 45, there is a tendency for the balls to cam out of the pockets 47 since these pockets are shallower than the recesses 46. The greater the torque the greater this camming tendency.

While there are two sets of shallow pockets 47 in the rear face of the driven clutch member 28, each of which set of three pockets is adapted to mate with the single set of recesses 46, preferably the pockets 47 are not coaxially aligned with the recesses 46, which recesses have the respective axes thereof parallel with the longitudinal axis of the tool attachment. As best seen in FIG. 8, the axis of each of the frusto-conical shaped pockets 47 is inclined from the plane of the rear face of the driven clutch member. As shown in FIG. 8, one portion 48 of the wall of the frusto-conical pocket 47 is normal to the face 49 of the driven clutch member while a portion 59 of the wall of the pocket opposite the portion 48 is inclined with respect to the face 49. As seen in FIG. 9, the axis of each of the pockets 47 lies in a plane which is parallel to the central longitudinal axis of the tool attachment. By this construction, as the driving mechanism of the tool attachment is rotating to the right as viewed from the rear thereof, the pockets 47 are so inclined that the inclined portions 50 of the pockets facilitate the camming out of the balls 45 from one of the sets of pockets.

Since the portions 48 of the pockets 47 are normal to the face 49 of the driven clutch member 28, a greater torque is required to cam the ball 45 out of the pockets 47 in the counterclockwise direction (as viewed from the rear of the tool) than in the clockwise or driving direction. This arrangement is of considerable practical importance in that after arotary fastener element, such as a screw or nut, has been driven to the predetermined torque value, it is not infrequent that the fastener element has to be removed or temporarily backed off. Normally, it

requires greater torque to remove a fastener element than the torque required for driving of the fastener. By hav-' ing the axes of the pocket 47 inclined in the driven clutch member in the manner described, the torque control clutch 3d automatically supplies a greater reverse or back-off torque in the counterclockwise direction than driving torque in the clockwise direction. Accordingly, it is merely necessary to reverse the motor in the power tool to removea rotary fastener element after it has been driven. No adjustments need be made to the tool attach ment 1e.

In addition to the torque control clutch 3th, the too'l attachment 10 also includes a positive clutch, generally indicated at 55. The positive clutch is so named since it is engaged in a positive manner in contradis'tinction to the torque 'control clutch 30 which is normally engaged except when a predetermined torque value is exceeded, whereupon it becomes momentarily disengaged. The clutch 55 includes a collar-like clutch member 56 which is non-rotatably and slidably disposed on the spindle 25 intermediate the length of the latter. The collar-like clutch member 56 includes three, equally spaced, axiallyextending recesses 57in the inner wall thereofQeach of which recesses is adapted to receive three of a plurality of balls 58, which balls are equally distributed and received in axially extending recesses 59 provided in the spindle 25, the recesses 59 being greater in length than the recesses 57. The arrangement ofthe balls and grooves just described is the equivalent of-a plurality 'of splines between the collar-like clutch member and the spindle. Accordingly, whenever the collar-like clutch member 56 is rotated it carries with it the spindle 25. However, the ball and groove arrangement permits free and easy rela tive axial shifting movement of the spindle and the collarlike clutch member.

Secured to the collar-like clutch member 56 and extending co-axially therefrom is a tubular member 61, the forward end of which tubular member is adapted to abut the rear end of the sleeve 27 for limiting forward axial shifting movement of the collar-like clutch member. The tubular section 61 defines with the spindle 25 an annular space adapted to receive a coil spring 62, which spring has the ends thereof in respective engagement with an inwardly extending annular flange 63 integral with the tubular section 61 and an outwardly extending annular flange 64 integral with the spindle 25. It will be apparent that the spring 62 constantly urges the tubular section 61 and the collar-like clutch member 56 attached thereto rearwardly in the casing of the tool attachment.

As best seen in FIG. 12, the rear face of the collar-like clutch member 56 is provided with three equally spaced teeth 66. Each of the teeth 66 has sides 67 concave along the length thereof and undercut as best seen in FIG. 13. Also provided in the rear face of the collar-like clutch member 56 are three arcuately extending recesses 68, which recesses define an annular space between the collar like clutch member at the rear end thereof and the spindle for reception of a coil spring 70. The spring 70, which frictionally engages the spindle and restrains rearward axial movement of the collar-like clutch member 56, will be referred to hereinafter. 1

As best seen in FIG. 10, the front face of the driven clutch member 28 is provided with three equally spaced teeth 72, which teeth are adapted for mating engagement with the teeth 66 on the rear face of the collar-like clutch member. The teeth 72 have straight sides 73, and they are undercut in a manner similar to the sides 67 of the teeth 66. By the provision of the undercut sides of the teeth 66 and 72, a positive and secure engagement is effected between the driven clutch member 28 and the collar-like clutch member 56 upon rearward axial movement of the latter member during operation of the tool attachment.

The forward portion of the spindle 25 includes an axially extending bore 75, which bore is hex-shaped along a portion of the length thereof for reception and driving engagement of a hex-shaped head of a tool bit, such as a screwdriving bit 76. The screwdriving bit 76 is adapted movement of the tool driving bit 76 is limited by the head 7 of the bit engaging an annular shoulder 80 formed in the bore 75. Accordingly, it will be apparent that inward axial movement of the tool driving bit 76 will result in inward axial shifting of the spindle 25. Inward movement of the spindle within the tool casing is limited by the rear or inner end of the spindle abutting a shoulder 82 formed by an enlarged bore communicating with the bore 31 in the power-receiving clutch member. The inner end of the spindle 25 includes a bore 83, which bore is adapted to receive a coil spring S4. The spring 84 has the ends thereof in respective engagement with the inner end of the bore 83 and a plug member 85, which plug member has the head thereof adapted for engagement with a projection extending from the stud 21 of the power tool shaft 20. It will be apparent that the spring 84 constantly urges the spindle 25 to the forward position thereof in the casing. Forward movement of the spindle 25 is limited by the annular flange 64 on the spindle abutting the inner end of the sleeve 27.

Preferably, the forward end of the tool driving bit 76 is sheathed within a finder device of known type, which finder includes a sheath 90. The sheath 90, which is slidable within the sleeve 27, is provided at the tip thereof with an internal, annular, beveled surface or mouth 91 which serves as a guide for placing of the sheath 90 over a rotary fastener element, such as a screw 92. The sheath 90 is nonrotatably mounted within the sleeve 27 by a detent 93, which detent projects through an aperture in the wall of the sleeve 27 and extends into a longitudinally disposed groove 94 provided in the sheath 90. The detent 93 is continually pressed inwardly by means of a ring-like clip 95, which clip is received and held in an annular groove in the sleeve 27. The sheath 90 is continually urged to its outer position by means of a coil spring 97, which spring has the ends thereof in respective engagement with the inner end of the sheath 90 and the outer side of the inturned annular flange which forms the bearing 26. The inner end of the slot 94 in the sheath member engages the detent 93 and acts as a stop to limit outward movement of the sheath 90.

The operation of the tool attachment of this invention is as follows: Assuming that the tool attachment 10 is in place on the power tool 12 as shown in FIG. 1, when the trigger 14 is depressed the electric motor of the power tool will be energized thereby rotating the shaft 20 in a clockwise direction, as viewed from the rear of the tool, which results in clockwise rotation of the power-receiving clutch 29. The driven clutch member 28 is also rotated with the power-receiving clutch member by means of the camming balls 45. The remaining mechanism within the casing of the tool attachment remains stationary. This is an important feature in that it keeps wear in the tool attachment to a minimum and it minimizes the drag placed on the power tool 12.

The tool is now manipulated so that the mouth 91 of the finder 90 is brought into engagement with the head of a rotary fastener element, such as a screw 92. Pressing of the tool attachment against the screw results in entering of the head of the screw within the mouth 91 with the result that further pressing of the tool toward the screw causes the sheath 90 to move within the sleeve 27 against the force of the spring 97 as shown in FIG. 3. When the tip of the screwdriving bit 76 is received in the slot in the head of the screw 92, additional pressure on the tool attachment toward the screw results in the head of the bit abutting the shoulder 80 in the bore of the spindle for rearward movement of the spindle within the casing of the tool attachment. Continued pressure on the tool attachment will result in rearward axial shifting of the spindle 25 against the spring 84. Rear-ward shifting of the spindle also results in rearward shifting of the collar-like clutch member 56 because of the spring 62 which has the ends thereof in respective engagement with the annular flange 64 on the spindle and the annular flange 63 of the tubular section 61, which tubular section is secured to the collar-like clutch member. As the spindle 25 moves reaiwardly in the tool casing the teeth 66 on the rear face of the collar-like clutch member will be brought into mating engagement with the teeth 72 on the front face of the driven clutch member before the inner end of the spindle abuts the shoulder 82 in the power-receiving clutch member. Because of the undercut sides on the teeth 66 and 72, once there is engagement of the teeth they attempt to cling together in a positive manner rather than tending to separate.

With the positive clutch 55 engaged by the mating engagement of the teeth 66 and 72, the collar-like clutch member will be driven by the driven clutch member 28 thereby resulting in rotation of the spindle 25, as the collar like clutch member is non-rotatably mounted on the spindle by means of the balls 58. Rotation of the spindle, and accordingly rotation of the screwdriving bit 76 held therein, results in driving of the screw 92 until the predetermined torque value established by compres;

sion of the spring 37 has been exceeded. It will be recalled that the predetermined torque value may be varied by means of the adjustment'nut 38. When this torque value is exceeded the balls cam out of one of the sets of three pockets 47 by rolling out along the inclined portions 50 of the respective pockets 47. control clutch 30 is now kicked-out or disengaged. At this time the position of the parts are as illustrated in FIG. 4. One of the main results of the' camming out of the balls 45 is the forward movement of the driven clutch member 28 against the force of the torque control spring 37. This forward movement of the driven clutch member 28 is accompanied :by forward movement of the collarlike clutch member on the spindle 25, i.e., the teeth on the front face of the driven clutch member and the teeth on the rear .face of the collar-like clutch member are still in mating engagement. This axial shifting movement of the collar-likeclutch member on the'spind-le is permitted by means of the balls 58 which are adapted to roll along the axially extending recesses 59 provided in the walls of the spindle. Forward axial movement of the driven clutch member 28 during momentary disengagement of the torque control clutch 30 also results in forward sliding movement of the spring 70 on the spindle as the rear end of the spring 79 is abut-ted by the forward face of the driven cltuch member 28. I

The parts of the driving mechanism of the tool attachment assume the posit-ions illustrated in FIG. 4 in an instant and remain in these positions only an instant. As soon as the camrning balls 45 are rotated by the powerreceiving clutch member to bring them into mating engagement with the next set of three shallow pockets 47 in the driven clutch member, this set of pockets receives the balls 45 thereby allowing the torque control spring 37 to force the driven clutch member 28 rearwa-rdly in the 1 casing until itagain engages the power receiving clutch member. As the driven clutch member 28 is snapped rearwardly by action of the torque control spring 37, the teeth 72 on the driven clutch member become disengaged from the teeth 66 on the collar-like clutch member 56 because the collar-like clutch member is prevented from shifting rearwardly along with the driven clutch memher by the action of the spring 70. The coil spring 70 engages the surface of the spindle 25 tightly fordeveloping a sufficient frictional force to prevent rearward shifting of the collar-like clutch member against the action of the spring 62. This condition of the parts with the torque control clutch 3i engaged and the positive clutch disengaged is illustrated in FIG. 5. In this condition, only the parts of the torque control clutch 3d are rotating; This results in what is known as non-ratcheting operation of the tool attachment, as there is no dragging movement whatsoever placed on the spindle 25. As long as pressure islrnaintained on the tool attachment against the screw head the various parts of the driving mechanism will remain in the position illustrated in FIG. 5; Thus, there is no ratchet-ing or dragging action of the tool attach ment once it has kicked-out or disengaged after the predetermined torque value has been exceeded.

Upon release of pressure against the rotary fastener element, the various springs in the tool attachment cause the parts of the tool attachment to resume the positions shown in FIG. 2. Thus, the spring 97 is allowed to urge the sheath 9t outwardly until the inner end of the slot 94 therein engages the detent 93. Also, upon release of pressure to the tool attachment the spring 34 shifts thev spindle 25 forwardly in the casing of the tool attachment until the annular flange 64 on the spindle abuts the inner end of the sleeve 27. As' the spindle is being shifted forwardly by action of the spring 84, the

The torque collar-like clutch member 56 will be carried forwardly v The collar-like clutch member will be carried forwardly 8 with the spindle until the forward end of the tubular member 61 abuts the inner or rearward end of the sleeve 27. As is apparent from FIG. 5, the forward end of the tubular member at will abut the inner end of the sleeve 27 before the flange 64 on the spindle abuts this same end of the sleeve 27. Forward shifting movement of the spindle after the forward end of the sleeve 61 is in abutting engagement with the'inner end of the sleeve 27 results in sliding movement of the spindle with respect to the coil spring 761,- as the coil spring is now prevented from moving forwardly by the collar-like clutch member. In other words, the frictional engagement between the spring 7b and the spindle is suificient for preventing rearward movement of the collar-like clutch member relative to the spindle, but this frictional engagement is not sufiicient for preventing forward shifting of the spindle by the spring 84 when the tubular member 61 is in abutting engagement with the sleet/e27. (Also, this frictional engagement is not sufficient to prevent forward shifting of the driven clutch member upon disengagement of the torque control clutch.) This action results in repositioning of the coil spring '79 and collar-like clutch member on the spindle for the next cycle of operation of thetool attachment.

Thus it will be seen that by this invention a new and improved t-ool attachment of simplified construction has been provided. The tool attachment is effective and durable in operation, and it is capable of being manufactured .at a competitive or lower price than presently avail- I able devices of similar type.

ing movement therein, means associated with the front end of said spindle for detachably engaging a tool; a main torque clutch in the rear end of said casing com prising, a power-receiving clutch member, a driven clutch member, said clutch members being rotatably supported in the casing axially of the spindle and'said driven clutch member .being supported in front of said power-receiving clutch member for axial reciprocal movement relative to the latter, disengageable camming means normally directly interconnecting said cl-uteh members and tending to separate said driven clutch member from said power-receiving clutch member, and spring means within said c-asing for urging saiddriven clutch member into driving engagement with said power-receiving clutch member and permitting separating of said clutch members by said camming means when a predetermined torque value is exceeded; and secondary clutch means for drivingly interconnecting said driven clutch member with said spindle upon rearward shifting movement of the spindle comprising, first engaging means on the front side of said driven clutch member, a collar-like clutch member slidably mounted on said spindle in front of said driven clutch member, which collar-like clutch member has second engaging means on the rear face thereof for interengaging with said first engaging means, said collarlike clutch member having a rearwardly facing annular shoulder encircling said spindle, coupling means interconnecting said spindle in driven relationship with said collar-like clutch member, second spring means for urging said collar-like clutch member into driven relationship with said driven clutch member, and ring-like means encircling said spindle adjacent said annular shoulder, which ring-like means is in snug slidable engagement with the spindle, means for sliding said ring-like means forwardly on the spindle upon separation of said clutch members for positioning the ring-like means in abutting relationship with said annular shoulder for holding the collarlike clutch member temporarily out of engagement with said driven clutch member when the latter is returned to driving engagement with said power-receiving clutch member after said predetermined torque value has been reached.

12. The combination as claimed in claim 1 wherein said ring-like means comprises a coil spring.

3. -In a tool attachment of the class described for driving and tightening rotary fastener elements, in combination: a generally cylindrical casing having a sleeve mounted in the front end thereof, a spindle co-ax-ially mounted in said casing for rotation and for axial shifting movemnet therein, which. spindle has the front end thereof disposed within said sleeve and which spindle has stop means thereon intermediate the length thereof for abutting said sleeve to limit forward shifting of the spindle, means associated with the front end of the spindle for detachably engaging a tool, spring means in said casing for urging said spindle forwardly; a main torque clutch in the rear end of said casing comprising, a powerreceiving clutch member, a driven clutch member, said clutch members being rotatably supported in the casing axially of the spindle and said driven clutch member being supoprted in front of said power-receiving clutch member for axial reciprocal movement relative to the latter, disengageable camming means normally directly interconnecting said clutch members and tending to separate said driven clutch member from said power-receiving clutch member, and second spring means within said casing for urging said driven clutch member into driving engagement with said power receiving clutch member and permitting separation of said clutch members by said camming means when a predetermined torque value is exceeded; and secondary clutch means for drivingly interconnecting said driven clutch member with said spindle upon rearward shifting movement of the spindle comprising, first engaging means on the front side of said driven clutch member, a collar-like clutch member slidably mounted on said spindle in front of said driven clutch member, which collar-like clutch memfber has second engaging means on the rear face thereof for interengaging said first engaging means, said collar-like clutch member having a rearwardly facing annular shoulder encircling said spindle, coupling means interconnecting said spindle in driven relationship with said collar-like clutch member, third spring means interposed between said stop means and said collar-like clutch member for urging the latter int-o driven relationship with said driven clutch member, and ring-like means encircling said spindle adjacent said annular shoulder, which ring-like means is in snug slidable engagement with the spindle, means for sliding said ring-like means forwardly on the spindle upon separation of said clutch members for positioning the ring-like means in abutting relationship with said annular shoulder for holding the collarlilce clutch member temporarily out of engagement with said driven clutch member when the latter is returned to driving engagement with said power-receiving clutch member after said predetermined torque value has been reached, said ring-like member being slidable on said spindle to permit relative axial movement between said collar-like clutch member and said spindle upon forward shifting movement of the latter for re-positioning of the collar-like clutch member on the spindle.

A. The combination as claimed in claim 3 wherein said ring-like means comprising a coil spring.

5. In a tool attachment of the class described for driving and tightening rotary fastener elements, clutch means for non-ratcheting operation of the tool attachment comprising, a spindle, a power-receiving clutch member, a driven clutch member, said clutch members being rotat- 10 ably supported axially of the spindle and said driven clutch member being supported adjacent said powerreceiving clutch member for axial reciprocal movement relative to the latter, disengageable camming means normally directly interconnecting said clutch members and tending to separate said driven clutch member from said power-receiving clutch member, spring means for urging said driven clutch member int-o driving engagement with said power-receiving clutch member and permitting separation of said clutch members by said camming means when a predetermined torque value is exceeded, a plurality of equally spaced first teeth extending from the side of the driven clutch member remote from the powerreceiving clutch member, a collar-l ke clutch member mounted adjacent said driven clutch member and being co-axial with the same, which collar-like clutch memher is drivingly interconnected on said spindle for axial shifting movement relative thereto, said collar-like clutch member having an annular shoulder on the face thereof adjacent said driven clutch member, which annular shoulder encircles said spindle, said collar-like clutch member having a plurality of equally spaced second teeth extending from the face thereof adjacent said driven clutch member for mating engagement with said first teeth, spring means associated with said spindle and said collarlike clutch member for urging said second teeth into mat-ing engagement with said first teeth, the sides of the first and second teeth being undercut to facilitate engagement of the first teeth with the second teeth, and ring-like means encircling said spindle adjacent said annular shoulder, which ring-like means is in snug slidable engagement the spindle, means for sliding said ring-like means axially on the spindle upon separation of said clutch members for positioning the ring-like means in abutting relationship with said annular shoulder for holding the collar-like clutch member temporarily out of engagement with said driven clutch member when the latter is returned to driving engagement with said power-receiving clutch member after said predetermined torque value has been reached, whereby said first teeth and said second teeth are disengaged upon axial movement of said driven clutch member toward said powerreceiving clutch member, said ring-like member being s'lidable on said spindle to permit relative axial move ment between said collar-like clutch member and said spindle upon shifting movemnt of the latter for re-posirtioning of the collar-like clutch member on the spindle.

6. The clutch means according to claim 5 wherein said ring-like means comprises a coil spring.

-7. In a tool attachment of the class described for driving and tightening rotary fastener elements, in combination: a generally cylindrical casing having a sleeve mounted in the front end thereof, a spindle co-axially mounted in said casing for rotation and for axial shifting movement within the casing, which spindle has the front end thereof disposed within said sleeve and which spindle has stop means thereon intermediate the length thereof for abutting said sleeve to limit forward shifting of the spindle, means associated with the front end of the spindle for detachably engaging a tool, first spring means in said casing for urging said spindle forwardly; a main torque clutch in the rear end of said casing comprising, a power-receiving clutch member, a driven clutch memher, said clutch members being rotatably supported in the casing axially of the spindle and said driven clutch memher being supported in front of said power-receiving clutch member for axial reciprocal movement relative to the latter, a disengageable camming means normally directly interconnecting said clutch members and tending to separate said driven clutch member from said power-receiving clutch member, and second spring means for urging said driven clutch member into driving engagement with said power-receiving clutch member and permitting separation of said clutch members by said camming means when a predetermined torque value is ex- 1 l ceeded; and secondary elutoh means for drivingly inter connecting said driven clutch member with said spindle upon rearward shifting-movement of the spindle comprising, first engaging means on the front side of said driven clutch member, a collar-like clutch member sl dably mounted on said spindle in front of said driven clutch member, the front end of said collar-like clutch member being adapted to abut saidv sleeve to limit forward movement of the collar-like clutch member, which collar-like clutch member has second engaging means on the rear face thereof for interengaging said first engaging means, coupling means interconnecting said spindle in driven relationship with said collar-like clutch member, third spring means interposed between said step means and said collar-like clutch member for urging the latter into driven engagement with said driven clutch member, and ring-like means encircling said spindle adjacent said annular shoulder, which ring-like means is in snug slidaole engagement with the spindle, means for sliding said ringlike means forwardly on the spindle upon separation of said clutch members for positioning the ring-like means in abutting relationship with said annular shoulder for holding the collar-like clutch member temporarily out of engagement with said driven clutch member when the latter is returned to driving engagement with said powerreceiving clutch member after said predetermined torque value has been reached, said ring-like member being slidable on said spindle to permit relative axial movement between the collar-like clutch member and the spindle when said collar-like clutch member abuts said sleeve and when said spindle is being moved forwardly by said first spring means.

8. In a tool attachment of the class described for driving and tightening rotary fastener elements, in combination: a generally cylindrical casing, a spindle co-axially mounted in said casing for rotation and for axial shifting movement therein, means associated with the front end of said spindle for detachably engaging a tool; a main torque clutch in the rear end of said casing comprising, a power-receiving clutch member, a driven clutch memher, said clutch members being rotatably supported in the casing axially of the spindle and said driven clutch member being supported in front of said power-receiving clutch member for axial reciprocating movement relative to the latter, spring means within said casing for urging said driven clutch member into driving engagement with said power-receiving clutch member and permitting separation ofsaid clutch members by said camming means when a predetermined torque value is exceeded; and secondary clutch means for drivingly interconnecting said idriven clutch member with said spindle upon rearward shifting movement of the spindle comprising, first engaging means on the front side of said driven clutch member, a collar-like clutch member mounted on said spindle in front of said driven clutch member for reciprocal movement axially of the spindle, which collar-like clutch memberhas second engaging means on the rear face thereof P for interengaging said first engaging means, coupling means interconnecting said spindle in drive relationship with said collar-like clutch member, and rlng-like means encircling said spindle and carried by the latter, said ringlike mean-s being engageable vwith said collard-ike clutch member and permitting relative sliding movement between the latter and the spindle whereby said collar-like clutch member moves forwardly with the driven clutch member after said predetermined torque value has been exceeded, and said ring-like means being adapted to engage the collar-like clutch member for preventing rearward axial movement of the same with said driven clutch member when the latter is returned to driving engagement with said power-receiving clutch member after said predetermined torque value has been exceeded.

References Cited by the Examiner UNITED STATES PATENT DAVID J. WILLIAMOWSKY, Primary Examiner.

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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3322205 *Apr 7, 1965May 30, 1967Chicago Pneumatic Tool CoAutomatic recycling nut runner
US3451514 *Dec 4, 1967Jun 24, 1969Milwaukee Electric Tool CorpAdjustable torque controlled release clutch for power driven tools
US4844177 *Aug 7, 1987Jul 4, 1989The Aro CorporationTorque sensing, automatic shut-off and reset clutch for toggle controlled screwdrivers, nutsetters and the like
US4880064 *Nov 5, 1987Nov 14, 1989The Aro CorporationTorque sensing, automatic shut-off and reset clutch for screwdrivers, nutsetters and the like
US5372206 *Sep 30, 1993Dec 13, 1994Makita CorporationTightening tool
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Classifications
U.S. Classification192/56.56, 173/178, 173/93, 81/451
International ClassificationB25B23/14
Cooperative ClassificationB25B23/141
European ClassificationB25B23/14C