USRE25274E - Torque clutch - Google Patents

Description

H. L. HAYES TORQUE CLUTCH Oct. 30, 1962 v 4 Sheets-Sheet 1 Original Filed April 1. 1954 ..3 mmf,

H/P/// Y 4 WZ W L? ff, Aw.; 1 ly HMM, 7W/3 r y Oct. 30, 1962 H. L. HAYES Re. 25,274

` ToRQUE CLUTCH Original Filed April 1, 1954 4 Sheets-Sheet 2 Henry Haag/es. l

Oct. 30, 1962 H. HAYES Re. 25,274

ToRQUE CLUTCH Original Filed April l. 1954 4 Sheets-Sheet 3 jl; INVVTR. //ewy Hayes.

Oct. 30, 1962 H. HAYES Re. 25,274

TORQUE CLUTCH Original Filed April 1, 1954 4 Sheets-Sheet 4 INVHVTOR.

Hen?! A #d es,

United States Patent lice Re. 25,274 Reissued Oct. 30, 1962 25,274 TORQUE CLUTCH Henry L. Hayes, Clawson, Mich., assignor to Roark Toark Tool Company, Madison Heights, Oakland County, Mich., a corporation of Michigan Original No. 2,966,973, dated Jan. 3, 1961, Ser. No.

420,383, Apr. 1, 1954. Application for reissue Feb.

13, 1962, Ser. No. 177,690

Matter enclosed in heavy brackets [1 appears in the original patent but forms no part of this reissue specification; matter printed in italics indicates the additions made by reissue.

My invention relates to mechanical torque transmitting devices and, in particular, refers to torque clutches which operate automatically to limit the magnitude of the torque that can be transmitted. Devices of this sort are comm-only used to tighten bolts, nuts, etc. This application is an application for the reissue of U.S. Patent N0. 2,966,973 issued January 5, 1,961, to' Henry L. Hayes.

Present commercial torque clutches of a mechanical type are not satisfactory to those in industry, principally because they are incapable of closely and accurately controlling Ithe maximum torque to be applied to the work being handled. They also tend to be rather bulky and cumbersome and to wear rapidly, or damage the Work, due to severe shock loads resulting from the nature of their operation.

It is the purpose of my invention to overcome these and other shortcomings of the prior art and to provide a compa-ct, substantially `friction-free and shock-free torque clutch construction of a mechanical type which will consistently deliver exactly the torque that it is set to deliver. In accomplishing this I use a special ball type clutch which throws out when the torque reaches a certain magnitude as determined by a spring. As the ball clutch `disconnects itself, it operates a ball cam arrangement that acts independently of the spring to furnish the dinal torque and angular movement to the output shaft and tool.

The invention includes a number of other features ot importance, such as automatic locking and unlocking, which will be described in detail in connection with the accompanying drawings of a preferred embodiment which has been selected to illustrate the principles of my invention:

FIGURE l is a longitudinal cross section through a torque clutch device embodying the invention;

FIG. 2 is a cross section, normal to the axis, taken on line .2 2 of FIG. l;

FIGS. 3-5 are diagrammatic views showing certain operating features of the construction;

FIG. 6 is a partial section taken on line 6-6 of FIG. l;

FIG. 7 is a longitudinal cross section through another form of the invention;

FIGS. `8-10 are diagrammatic views showing certain operating features of the construction;

FIG. ll is a view similar to FIG. 6 of the modified form; and

FIG. l2 is a view of the lock between the sleeves and output member.

CONSTRUCTION The torque clutch mechanism of this invention re- Y a spindle 11 that threads into the collar 5, as shown at 13, so that rotation of the collar rotates the spindle. The spindle 1.1 has an enlarged `diameter 15 that provides a shoulder 17 against which the washer 19 is pressed by a spring 21 which is confined between the Washer and head 1. It will be seen that the spring 21 normally holds the projection 7 in the top of slot 9 but that Ithe collar 5, spindle V11, and connected parts can all be moved upwardly for a limited distance against spring 21 toward the head and relative to drive 3 to provide a certain amount of yieldable ilexibility in the over-all length of the mechanism.

The rotary spindle 11 is rotatably mounted in a sealed ball bearing set 23, the inner race of which is tted on portion 2.5 of spindle 11 and the outer race of which is seated on Shoulder 27 of sleeve 29. A cap 31 threads into the top of sleeve 29 and the flanged edge 33 thereof rests on the top edge of a bronze, [oilite,] Oilte, or other suitable kind of bearing sleeve 35. The bearing sleeve 35 is suitably attached by screws, rivets, etc., to an `outer casing 37 and the latter has upwardly extending arms 39 that may be bolted to the machine 1. It will be seen that the casing 37 `may carry most of the Weight of the mechanism by virtue of the connection of sleeve 29 and cap 31` to the bearing 35.

The lower part of spindle portion 25 is threaded into a top or driving clutch plate `41 so that the two rotate together. A Washer 43 between the inner race and the plate 41 acts to space the plate from the bearing. The clutch plate 41 drives the lower or driven clutch plate 45 through a plurality of balls 47 preferably five in number, which are preferably equiangularly spaced around the axis of the plates 41 and 45 (the drawing showing two balls on a diameter in order to make the construction more readily understood). The clutch plates 41 and 45 have registering identical drilled holes 49 and 51, respectively, of slightly smaller dia-meter than the balls, in which the balls are seated to key the clutch plates together. It is to be noted that the balls are seated on the sharp, squared edges 53 of the drilled holes so that there is merely a circular line contact between each ball and plate. This feature permits high torque transmittal, minimizes surface contact and friction, and makes it possible to rework the ball seats by sirnply grinding a few thousandths ol the flat, drilled faces 55 and 57, respectively, of the plates 41 and 45 to produce sharp, new edges 53. The line contacts of the balls with the edges 53 are preferably rather near the midplanes of the balls, the distance of them `from the midplanes affecting, of course, the torque that they can transmit without rolling out of the holes. If desired, a plate retainer can be used for the balls to hold them in proper radial position as shown in FIG. 7, though this is not thought to be necessary.

'I'he two clutch plates are centered or axially aligned with each other by means of the spindle 11 which has a stem 59 extending through the plates. The stem 59 also serves to align a spring 61 which bears upon the bottom of plate 45 to force it up against the balls 47 and toward the plate 41. When the torque transmitted from plate 41 to plate 45 through the balls 47, exceeds a value predetermined by the spring 61, the balls will force the plate 45 down and snap out of their seats 53 to disconnect plate 45 from plate 41.

Prior to disconnection and when the balls 47 operate to drivingly connect plates 41 and 45, clockwise driving rotation from plate `45 is transmitted to ratchet sleeve 63 by means of interiitting ratchet teeth 64a and 64b on the plate 45 and sleeve 63, respectively. A spring 68 engages the bottom of sleeve `63 to yieldably hold the teeth in engagement but to permit downward movement of the sleeve 63 along with lower clutch plate 45 when the balls 47 come out of their seats.

Rotary movement of the ratchet sleeve 63 is transmitted to a cam sleeve `615 by a cam-key connection that, upon downward axial movement of sleeve 63, forces the sleeve 65 to move angularly (rotatably) relative to the rotatable parts, such as 63, 45, 41, `11, and 3, that have already been described. The angular movement of sleeve 65 is such that it is speeded up or moves ahead of parts 63, 45, etc. The cam-key connection comprises a series of slots 67 (preferably three) formed in sleeve 63 and the same number of slots 69 in the sleeve `65. The slots 67 and 69 register with each other when the balls 47 are in their recesses 49 and S51. The slots `67 and 69 are preferably straight (even though out 4on cylindrical surfaces) and are all cut on the same angle. For manufacturing reasons, the slots `697 will normally lbe cut clear through the wall of sleeve 65 but slots 67 will normally be -grooved out of the periphery yof sleeve 63. The slots are inclined so that the top end is the leading edge with respect to the direction of rotation. The angle between each slot and a vertical line extending up from the -bottom of the slot is preferably around BiO-60 degrees. A plurality of balls 71, preferably :about five, are disposed in eac-h pair of registering slots 617-69 and act as friction-free keys between the sleeves 63 and 65. The balls 71 will roll to the bottoms (trailing edges) of slots 67 and 69 when the parts are not revolving; however, upon rotation, the balls will be driven by the bottoms (trailing edges) `of slots 67 and will drive the tops (leading edges) of slots 69. The Iballs 71 hold the slots 67 and 69 in exact registry. Hence, when the sleeve 63 is forced down dur* ing the instant of disconnection (by balls 47), the walls of rslots 67 in sleeve 63 will carry the :balls 711 down with the sleeve. Since the balls 71 are moving down and they engage the walls of slots 69 in sleeve 65, they will try to force the sleeve 65' to move down also. The sleeve V65, however, is iixed in axial position and cannot move down. The balls 71 will therefore have to roll down the incline of slots 69 and since the balls are being pressed with an axial force against the incline they will wedge or cam sleeve 65 forward in the direction of rotation (and relative to sleeve 63) until the balls 47 are out of holes 49 and 51 (FIG. l5). The angle of the slots will determine the mechanical advantage of this camming action `and in conjunction with the diameter of balls 47 will determine the amount of such rotation relative to sleeve 63. It is possible, therefore, in the design of the unit to control or predetermine these factors.

The cam sleeve `65 is supported in lfixed axial position by a bottom cap 73 that threads onto the bottom end of sleeve 29. The sleeve 65 has three openings 75 in its side which register with identical openings 77 in the wall of sleeve =29. Locking balls 79 having a diameter sub stantially larger than the combined thicknesses of the sleeves is confined in the pair of registered openings by a locking sleeve 81. The ratchet sleeve `63 has three ball seats 83 of suitable shape located above its bottom end at a position such that `the balls 79 will enter it when the sleeve is axially moved down by balls `47 and lock it in such axial position wherein the mechanism has cut out and is inoperative to transmit torque. The locking sleeve 81 has a top and large inner diameter portion 85 which permits the ball to `be moved radially outwardly in holes 75 and 77 so that the sleeve `63 can occupy its operative position of FIG. i1. The sleeve `81 has an inner reduced diameter portion which provides top and bottom shoulders `87 and 89, respectively, and ball engaging diameter 91. -A spring 93 is compressed between shoulder 89 and the top of cap 73 and when the sleeve 63 is moved axially down so that seat y83 registers with the ball 79 it 4forces the locking sleeve l'81 upwardly and slanted shoulder 87 cams the ball 79 radially inwardly into the seat 83 to lock the sleeve 63. 'I'he diamter 9.1 will then be-in line wit-h the Iballs and will holdfit on its seats 83.

In this position of the sleeve its top will be immediately adjacent if not in contact with the bottom edge of casing 37. It will be clear that the balls 79 will be released and the sleeve 63 unlocked by depressing sleeve `S1 against spring 89 until large diameter 85 is in line with the balls whereupon pressure of spring 68, seated on cap 73, to raise sleeve `63 Iwill cam the balls 79 outwardly to unseat it from seat 813. The locking sleeve 81 can be forced down by hand in order to unlock or this can be accomplished -mechanically because of contact of casing 37 with sleeve 81, the spring 2.1 and collar *5 construction permitting relative axial movement of the casing and sleeves 2,9 and 65 when the head -1 is yfed toward the work and the clutch mechanism is prevented from such movement by contact with the work.

Rotation and angular movement of cam sleeve 65, as already described, is transmitted by balls 79 to sleeve 29' and thence yto bottom cap 73. Power output shaft is threaded into cap 73 and held in axially adjusted position by lock nut 97 that is lthreaded on to the shaft against the bottom of the cap. Shaft 95` is, of course, coaxial with the other rotary parts of the mechanism and by threading it in or out of the cap 73 it moves along the axis of revolution so that the axial position of its top end is varied relative to the :other parts. The top of sha-ft 95 carries a ball bearing set 99` that seats on a reduced diameter portion 101 of the shaft. The outer race of the ball bearing rotatably supports a seat 163 for spring 61, the seat having alignment stern 105 projecting toward stem 59 and being able to rotate relative to the other parts of the device. Being carried by shaft 95, the seat 163 can be adjusted axially relative to the bottom of driven clutch plate l415 thus making it possible to vary the initial setting of spring 61 and the torque at which the balls `47 roll out of holes 49 and 51.

The power output shaft `95 has a shoulder i165 and projection 167 or any other suitable means whereby a tool, such as a hex socket for tightening bolts, etc., can be readily and operatively coupled to it.

OPERATION During operation of the mechanism to transmit power from power input shaft 3 to power output shaft 95, clockwise rotation of shaft 3 causes the collar 5 -to rotate and this rotates spindle 11. The spindle rotates top clutch plate 41 and this rotation is transmitted to lower clutch plate 45 by virtue of `balls 47 which are seated on the edges 53 `of holes 49l and `51 in the clutch plates. The lower clutch plate l45 has ratchet teeth 64a which engage the teeth 64b on ratchet sleeve i63 so that clockwise rotation of plate 45 causes similar rotation of sleeve 63. By virture of the cam-key connection provided by balls 71 acting in slots 67' and 69, rotation of sleeve 63 'is transmitted to cam sleeve 65. One or more lock :balls 79 tit in pairs of holes 75 and '77 of sleeves 65 and 29 so that rotation of sleeve 65 causes rotation of sleeve 29. The cap 73 is fixed to sleeve 29 and therefore rotates with it. Since power output shaft 95' is fixed -to cap 73 for rotation with it, the torquetransmitted through the various parts, as just described, can be removed by suitable connection to shaft 95.

The power supplied by input shaft 3 is determined by the resistance which the output shaft A95 encounters. In the usual type of use, eg., tighten-ing bolts, studs, ietc., the resistance increases as rotation of the output shaft 95 continues. In other words` the work `will usually require Ithat a constantly increasing .torque -be applied to it [its] by shaft 95. The machine 1, however, is powerful enough to `deliver torque which is greatly in excess ofthat which most work can safely receive. For example, the machine '1 could probably, in most applications, easily shear off the head of a stud screwed into a block. Hence, as a safety measure, it is desirable to provide Aa clutch mechanism that will automatically cut out or disconnect .t-he power input shaft .from the Power output aarli shaft when a predetermined maximum torque is reached for the particular job being done. It is also very desirable to provide such a clutch mechanism for the sake of torque control itself since cut 4olf at a predetermined torque will make it possible to control the prestressing of the work which receives torque from output shaft 95. To mention a familiar example, the maximum torque applied to a bolt that is threaded in place will determine the amount of its elongation `and the tension in it. ln the past, however, mechanical torque clutch devices were not accurate; there was actually a variation in the order of at least plus or minus ve foot pounds in the torque at which the clutch would operate even though set for a definite maximum torque. Theoretically, the devices would give a certain precise maximum torque but in actual use they cut off unpredictably anywhere over a rather wide range of torques. This characteristic has made them very unsatisfactory as a means for prestressing bolts, studs, etc. The present construction, however, is very reliable in this respect and can be successfully used as a torque control or prestress control means.

As indicated hereinbefore, the length of spring 61 can be varied by means of shaft 95 and this adjustment determines the maximum torque that the balls {walls} 47 will transmit `from clutch plate 41 to clutch plate 45. When the work calls for a torque to be delivered from input shaft 3 to output shaft 95 which is -in excess of the maximum as determined by spring 61 (plus, of course, weaker spring 68), the couple on each of the balls 47 will force them to start to roll to the left out of their seats on the edges of holes 49 and 51. The balls 47 act like cams and wedge the plate 45 (and Asleeve 63) down- Wardly -against the resistance of spring 61. Because of the line contact feature due to sharp corners 53, friction is minimized and the balls seem to actually roll rather than slide and for this reason the clutch itself does not throw an additional torque absorbing resistance into the system. While the precise action of the balls 47 has not been observed, it seems that eventually the balls 47 are completely out of the holes 49 and 51 (see FIG. 4) and maximum downward movement of members `45 and 63 has occurred, At this point the lock ball 79 is pushed into recess 83 by the pressure of spring 89 on lock sleeve 81 and the sleeve 63 is locked in down position. Continued rotation of top clutch plate 41 brings the next holes 49 and 51 into -alignment with each ball 47 and the pressure of spring 61 forces the balls to seat `again and lifts plate 45 from sleeve 63 so that ratchet teeth 64a and 64b are ydisengaged (see FIG. 5 In this position clutch l plates 41 and 45 will rotate idly supported by spring 61 which is permitted to rotate because of its ball bearing seat 103, but sleeve 63 is stationary :and no torque or rotation reaches output shaft 95.

The torque at which the springs 61 and 68 are overcome and at which the balls 47 roll out of the holes over faces 55 and 57 of clutch plates 41 and 45 is not the maximum torque `delivered to output shaft 95. As pointed out hereinabove, when 'the sleeve 63 is cammed down by balls 47 the balls 71 are carried downwardly with the sleeve. The balls 71 therefore operate in slots 69 of sleeve 65 to cam it `angularly about the axis of revolution and this applies a torque to output shaft 95 that is greater than the maximum torque as determined by the spring 61. The magnitude of the cam torque and the degree yof angular movement can, as mentioned before, be regulated by the slope of the slots and `diameter of balls 47. Since the cam torque is not action in opposition to springs 61 and 68 which have already been overcome it will be seen that the control spring 61 can be much smaller and weaker than it would be if the cam-key connection was not used. The last bit of angular movement of the work (eg. bolt, nut, etc.) requires the most torque and it will be seen that this is accurately and positively provided by cam balls 47 and cam balls 71 independently of the various springs. In other words the maximum or cut-out torque of the clutch mechanism is dependent upon the operation of balls 71 in slots 67 and 69. Viewing the torque disconnect as a whole, it will be noticed that the control spring 61 puts ball cam 47 system into operation and that this in turn operates the ball cam 71 system. The ball cam 47 system stops automatically when the balls are out of holes 49 and 51 and this, of course, deactivates ball cam 71 system and power output shaft 9S.

After the unit has disconnected itself, the sleeve 63 will be locked in down position by ball 79 and locking sleeve 81 which will be in up position in contact with the bottom of casing 37. In this condition the sleeve 63 `and output shaft 95 will be stationary so that the tool carried by shaft 95 can engage ythe work without damage to either. When the t-ool on shaft 95 is aligned with a bolt to be tightened, or other workpiece, and then the head 1 is moved down to effect operative engagement of tool and workpiece, the Contact of `the tool (which is not rotating) with the workpiece will x the axial position of `shaft 95, cap 73, sleeve 29, bearing 23, spindle 11, and collar 5 but the casing 37, bushing 35, and power input shaft 3 can continue to move down `axially against the resistance of spring 21. During lthis movement of casing 37, it will move the locking sleeve 81 downwardly and after a short axial movement thereof the enlarged diameter of the sleeve will reach the level of locking ball 79 which will be cammed out by curved seat 83 under relatively light pressure from spring 68 acting to push the sleeve 63 upwardly. When the ball 79 is out of seat 83, the sleeve 63 will return to its up position wherein its ratchet teeth 64b engage :teeth 64a of plate 45 `and the output shaft 95 will be operatively connected to input shaft 3 to rotate the tool which is already engaged with the Work. Thus the mechanism which has been automatically locked at the maximum torque is autolrnatically unlocked. It is to be noted that by using the ratchet teeth connection between members 45 and 63 reconnection is achieved by means of relatively light spring 68 which stores much less energy than spring 61, thus minimizing shock. Such shock as may occur upon reengagement or unlocking of the mechanism will be taken by spring 68 and will not be transmitted to the output shaft 95.

CONSTRUCTION OF MODIFIED FORM The modied form of torque clutch mechanism of this invention is shown in FIGS. 7-12. It receives rotary driving torque .from any suitable machines or power drive. A fragment of the head of a machine 201 is illustrated and it has the rotary square drive 202 that rotates the drive collar 203 and has a radial projection 204 disposed in a hole 205 in the collar to prevent the collar from slipping off the drive 202. The torque clutch has a spindle 206 which is part of ball plate 207 and which threads into collar 203 so that the rotation of the collar rotates the ball plate 207.

The rotary spindle 206 is mounted in a sealed ball bearing set 4208, the inner race of which is fitted on portion 209 of the spindle part of ball plate 207 and the outer race of which is seated on top of sleeve 210 con- 'tained incasing 211. A cap 21-2 threads on to the top of casing 211 holding the outer race 208 on lthe top of sleeve 210. A shoulder 213 on |ball plate 207 supports the inner race of bearing 208. Clutch plate 207 drives the lower clutch plate 2'1-4 through a plurality -of balls 215 preferably five in number, which are preferably equiangularly spaced varound the axis of the plates 207 and 214 (the drawing showing two yballs on a diameter in order to make -the construction more readily understood). A spacer 216 is placed between the plates 2.07 and 214 to keep the balls 215 equally spaced at all times. The spacer or ball locater which may be used in the form of FIGS. 1-6, is preferably at least one-half the diameter of the balls to provide positive insurance against the possibility of jamming due to uneven spring pressure on the various balls. The clutch pla- tes 207 and 214 have registering identical `drilled holes 217 and 218, re spectively, of slightly smaller diameter than the balls 215, in which lthe balls 215 are seated to key the clutch plates 207 and 214 together. It is to be noted that the balls `are seated on the sharp, squared edges 219A and 219B of the drilled holes so that there is merely a circular line contact between each ball 215 and the plates 207 and 214. This feature permits high torque transmittal, minimizes :surface contact and friction, and makes it possible to rework the ball seats by simply Igrinding a few thousandths lolf the hat drilled faces 220 and 221, respectively, of the plates 207 and 214 to produce sharp, new edges 219A and 219B. The line contacts of the balls 215 with the edges 219A and 219B are preferably rather nea-r the midplanes of the balls 215, the distance of them from the midplanes affecting, of course, -the torque that they can transmit without rolling out of the holes.

The holes 222 in the spacer 216 are slightly larger than the balls 215 to permit the balls 215 to move freely. The clutch plates 207 and 214 and the spacer 216 are centered Ior axially aligned by the shaft 223 which is threaded -into the plate 207. The shaft 223 also serves to align the spring 224 which bears upon the thrust bearing 225A which in turn bears upon plate 214 to force it up against the balls 215 and toward plate 207. When the torque transmitted from the plate 207 to the plate 214 through the balls 215 exceeds a value determined by the spring 224, the balls 215 will force the plate 214 down and roll out of their seats 219A and 219B and disconnect plate 214 from plate 207.

The adjustment of tension on spring 224 is made by threading adjusting sleeve 225 to the desired position on shaft 223; then Allen .screw 226 threaded within sleeve `225 is tightened to abut lagainst the end of shaft 223 to lock the sleeve 225 in position.

Prior to the vdisconnection and when the balls A215 operate to drivingly connect the plates 207 and 214, clockwise driving rotation from plate 214 is transmitted to ratchet sleeve 227 by means of interiitting ratchet teeth 264A and 264B on plate 214 and sleeve 227, respectively. The split circular lat spring 228 which is attached by a rivet or screw to casing 211 forces three balls -229 through holes in the casing 211 and sleeves 210 and -232 into re cesses 230 in ratchet sleeve 227 to hold the teeth 264A and 264B of plate 214 and sleeve 227 in engagement. Spring 228 permits downward movement of sleeve 227 lby letting lock balls `229 be forced outward :and then forcing -them into recesses 231, thus holding sleeve l227 in the downward or disengaged position when plate 214 moves downward as the balls 215 roll off of their seats. When the cam 227 engages the cam 214, the lock ball 229 is -seated in the recess 230. Whe-n the cam 227 disen- -gages the cam 214, the lock ball 229 is in recess 231. The recess .231 is located closer to the teeth 264B than recess 230. A line through the centers of recesses 230 and 231 is parallel to slots 233 and located halfway between each pair of slots 233.

The rotary movement of ratchet sleeve 227 is transmitted to the cam sleeve 232 by a cam-key connection zthat, .upon downward axial movement of sleeve 227,

forces the sleeve 232 to move `angularly (rotatably) rela- Vtive to the rota- table parts 227, 214, 207, and I203, that .cut on cylindrical surfaces) and are -all cut yat 4the same angle. For manufacturing reasons (avoid cutting the grooves on the I.\D.), the slots 234 will normally cut kthrough the wall of sleeve 232 but the slots I233 will be inserted in the grooves.

relative to sleeve 227.

' grooved out of the peripheryof sleeve 227, the slots opening out of the Itop of sleeve 227 to permit the balls to be The slots .are inclined so that the top end is the leading edge with respect to the `direction of rotation. The angle between each slot and a vertical line yextending from the bottom of the Islot is preferably around 30--60` degrees. A plurality of balls 235, preferably about tive, are disposed in `each pair of registering slots 233-234 and act :as friction-free keys between sleeves 227 `and 232. The balls 235 will roll to the bottom (trailing edge) of slots 233 in sleeve 227 and to the top (leading edge) of slots -234 in sleeve 232 when clutch is in engaged position. When the sleeve 227 is Iforced Vdown du-ring the instant of disconnection (by balls 215) the fballs 235 will roll toward the top (leading edge) of slots 233 in sleeve 227 and ytoward the bottom (trailing edge) of slots 234 of sleeve 232. Hence, when the `sleeve 227 is forced down during the instant of disconnection (by balls 215), the walls of `slots 2'33 Iin sleeve 227 will carry the balls 235y down with the sleeve. Since the balls 235 yare movi-ng down and they engage the walls of slots 2.34 in sleeve 232, they will try to force the sleeve 232 to move down also. The sleeve 232, however, is @fixed in axial position and cannot move down. The balls 235 will therefore have to roll down the incline of slots 234 and since the balls are being pressed with an axial force against the incline they will wedge or cam the sleeve 1232 forward in the direction of rotation (and relative to sleeve 227) until the balls 21-5 are ou-t of the holes 219A and 219B (FIG. 5). The angle of the slots will determine the mechanical advantage of this camming action and in conjunction with the diameter of iballs 215 will determine the .amount of such rotation It is possible, therefore, in the design of the unit to control or predetermine these factors.

The torque is transferred from the driving unit 2011 through the driver 202, clutch parts 20'3, 207, 215, 214, 227, 23-5 and 232. Driving plate 236 is connected to the bottom of sleeve 232, 210, :and casing 211 by three lugs -23'7 which register with three slots 238 in parts 232, 210 and 21=1. The plate 236 is locked in position by end cap 239 thu-s retaining parts 232, 210 and 211 in the exact relative position with each other -at -all times. [Plates] plate 236 has a square hole 240 through which the square driver 241 projects and is movable axially. The square driver 241 is fastened by a cotter pin or the like to washer 242 at its upper end. The bushing 243 is held down on washer 242 by yspring 244 one end of which is held stationary Iby shoulder 245 in sleeve 232. The spring i244 thus 4forces Abushing 243 down on washer 242 which hold driver 241 so [its] it projects its maxi` mum length through plate v236. The drive 246 is part of driver 236 and is located 'outside of the clutch. vLocated in `drive 246 is a projection '247 to hold sockets or other units being used with the clutch.

OPERATION OF MODIFIED FORM `During operation of the mechanism to transmit power from power input shaft 202 to power output shaft 246, clockwise rotation of shaft 202 causes the collar 203 to rotate and this rotates spindle 206. The spindle rotates top clutch plate 207 and this rotation is transmitted to lower clutch plate 214 by virtue of balls 215 which are seated on the edges 219A and 219B of holes 217 and 218 in the clutch plates. The lower clutch plate 214 thas ratchet teeth 264e which engage the teeth 264b on ratchet sleeve 2-27 so that clockwise rotation of the plate 214 causes similar rotation of sleeve 227. By virtue of the cam-key connection provided by the balls 235 acting in slots 233 and 234, rotation of sleeve 227 is transmitted to cam sleeve 232. The sleeve 232 transmits rotation to drive plate 236 `through lugs 237 in slots 238. Drive plate 236 rotates square driver 241 and square drive 246 by square hole 240` inrplate 236. Torque transmitted through "together, said spring means being overcome at a predetermined Ftransmitted torque to permit axial movement .of said one member away from the other and to release said rolling means yand prevent substantial torque transmittal between the members, a clutch element free of said spring means and abutting said one member in a .driven torque transmitting connection and movable with it away from the other member to a position wherein said rolling means is released, releasable llock means for holding the element in said position, said-spring means acting to separate said one member from said element land `break said connection when said element is locked Vin said position, and a second spring means of less vresistance than the first acting upon said element to force it 4,against-said one member yand reestablish said connection when said element is released from locked position.

5. The invention set forth in claim 4 including a rotatable seat supporting the end of said first spring means opposite to said one member to permit rotation thereof relative to the clutch element.

6. The invention set forth in claim 5 wherein said seat -is adjustable along the axis of rotation to vary the effec- `tive length of the spring means.

7. In a torque clutch, a rotary driving member, a rotary driven member, -sleeve means coaxial with the axis of revolution of said members, means connecting the .driven member to the sleeve means to transmit torque thereto, afcap across the bottom of said sleeve means, a power output shaft threaded into said cap on said axis yof rotation and capable of movement relative to said driven member in an axial direction, releasable torque .transmitting means interconnecting thedriving and driven members, a coil spring housed in said sleeve means and acting against the driven member to press it toward the `driving -member and Ahold the releasable means in operative position, aspring seat rotatably supported on and axially movable withfsaid-output shaft, saidspring being seated on said seat.

S. In atorque clutch, a torque-receiving shaft, a rotary sleeve, means for Ytransmitting torque from the shaft to `the sleeve and -disconnected at a predetermined torque `andfoperative yduring disconnection to move said sleeve along `its axis Yof rotation, a `second sleeve coaxial with the -rst and vfixed-in yaxial position, said-sleeves having registering inclined slots in the confronting walls thereof, ball `means `in said slots and keying the `sleeves to- -gether and operative in said slots upon axial movement ,of the first ksleeveto angu-larly `move the second sleeve relative .to the first, and a torque delivering shaft operatively connected to said second sleeve.

9. A torque clutch for attachment to `a machine having a feed head with a rotary power-output shaft therein, comprising, a housing secured to said head for feed .motion therewith, avcollarrotatably secured to said out- Iput shaft `but axially movable relative thereto, spring means acting to force the collar away from the head, a spindle fixed to said collar and driven thereby, a first .sleeverotatablycarriedby the casing, abearing rotatably supporting said spindle and carried-by said first sleeve adjacent ,one end thereof, arst rotary clutch plate xed .to -said spindle and having a flat radial face normal to with the jaws on the second plateto receive ltorque there- '12 fr0 n1, Said second sleeve being axially movable away from the second rotary plate to disconnect said jaws, first spring means acting onthe second sleeve to axially urge it into position in which -the jaws are connected, a first sleeve and saidsecond sleeve having registering inclined slots formed in the respective inner and outer walls therevof, the leading ends of said slots with respect to the direction of rotation of said second sleeve being axially closer to said jaws than the trailing ends, balls in said inclined slots keying the sleeves together for joint rotation but permitting axial movement of the second sleeve with `respect to the first sleeve when said jaws are disconnected, said irst sleeve having an opening ythrough the wall `thereof and said second sleeve having a recess that aligns with the opening when the second sleeve is in an axial position in which the jaws are disconnected, a ball in said opening and movable into said recess to lock the second sleeve in said axial position, a lock sleeve axially movable on said rst sleeve and having a large diameter portion and a small diameter portion, both `said portions being alignable with said opening, said ball being of larger diameter than the thickness of said first sleeve wall whereby it is pushed inwardly into said recess when the small diameter portion of the lock sleeve is aligned with the opening, the large diameter permitting the ball to move radially out of said recess Whenin alignment with said opening, second spring means urging the lock sleeve to move so that the small diameter portion is aligned with said opening, said lock sleeve being engageable by said housing when the small diameter portion thereof is aligned with the opening whereby feed movement;of -the head and housing will move the lock sleeve relative to the first sleeve to release said ball, said first sleeve having a bottom atiixed thereto, a power output -shaft secured to said bottom to receive'torque from said iirst sleeve, means providing axial adjustment of said out- ;put shaft relative to said first sleeve, aspring seat carried `by Vsaid shaft within the sleeve, said seat being axiallyad- `justable with the shaft but rotatable relative to the shaft, anda spring seated on said seat and bearing on the second clutch -plate tourge said radial faces together.

l0.`I-n atorque clutch, a driving clutch plate, a driven :clutch plate, rolling means between confronting faces of V thev [plate] plates and acting to key them together, a driven member adjacent said driven plate, cooperating ratchet -teeth on said member and driven plate connecting them together for angular movement in one direction, `said :driven plate having a center hole therethrough, a rod extending through said hole and anchored in said driving plate, and a coilfspring associated with the rod pressing against said driven plate anda shoulder on the rod to resist separation of the plates, said spring being located in a hole in said driven member.

l1. In a torque clutch, a rotatable and axially movable first sleeve, means operative at a predetermined torque `to move said sleeve axially in one direction and disconnect it yfrom va source of rotation, a rotatable second sleeve, cam-key means yconnecting the two sleeves so that axial movement of the first sleeve causes rotation o f the second sleeve, means providing a radial shoulder facing opposite to said one direction and spaced axially therefrom in the direction of axial disconnecting movementof said'first sleeve, a torque output member seated on-said shoulder and connected to said second sleeve for rotation therewith, and means associated with said-member for engaging said first sleeve to prevent relative axial movement of the first sleeve and member in said one direction, said second sleeve being movable axially in said one direction relative to said member.

l2. In a torque applying device, ya power input member, a power output member, a first rotary element connected to one of the members, a second rotary element connected to the other of said members, said elements being axially movable relative to each other along their Aaxis of rotation, said elements having confronting surfaces with registering slots therein inclined to said axis of rotation of said elements, key means in said slots keying the elements together so that relative axial movement of the elements causes rotation of one of the elements in a direction to apply torque, and means responsive to torque transmitted by said device for moving said elements axially relative to said other.

13. In a torque clutch, a driving clutch member, a driven clutch member, connecting means between the members for connecting them together to transmit torque, one of the members being axially movable, first spring means acting against said one of the members to press them together, said spring means being overcome at a predetermined transmitted torque to permit axial movement of said one member away from the other and to release said connecting means and prevent substantial torque transmittal between the members, a clutch element free of said spring means and abutting said one member in a driven torque transmitting connection and movable with it away from the other member to a position wherein said connecting means is released, releasable lock means for holding the element in said position, said spring means acting to separate said one member from said element and break said connection when said element is locked in said position, and a second spring means of less resistance than the first acting upon said element to force it against said one member and reestablish said connection when said element is released from locked position.

14. The invention set forth in claim 13 including a rotatable seat supporting the end of said first spring means opposite to said one member to permit rotation thereof relative to the clutch element.

15. The invention set forth in claim 14 wherein said seat is adjustable along the axis of rotation to vary the effective length of the spring means.

16. In a torque clutch, a driving clutch plate, a driven clutch plate, connecting means between confronting faces of the plates and acting to connect them together, a driven member adjacent said driven plate, cooperating ratchet teeth on said member and driven plate connecting them together for angular movement in one direction, said driven plate having a center hole therethrough, a rod extending through said hole and anchored in said driving plate, and a coil spring associated with the rod pressing against said driven plate and a shoulder on the rod to resist separation of the plates, said spring being located in a hole in said driven member.

References Cited in the tile of this patent or the original patent UNITED STATES PATENTS 748,018 Rowe Dec. 29, 1903 1,118,132 Jones Nov. 24, 1914 1,555,098 Benko Sept. 29, 1925 1,725,562 Borchert Aug. 20, 1929 1,813,372 Wildhaber July 7, 1931 2,248,133 Snow July 8, 1941 2,259,149 Cederstrom Oct. 14, 1941 2,259,839 Van Sittert Oct. 21, 1941 2,263,709 Van Sittert Nov. 25, 1941 2,490,172 Swahnberg Dec. 6, 1949 2,684,738 Kaplan July 27, 1954 2,732,050 Van Sittert Jan. 24, 1956

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