US2439823A

US2439823A - Impact clutch

Info

Publication number: US2439823A
Application number: US467659A
Authority: US
Inventors: Porter Carl Wesley
Original assignee: Individual
Current assignee: Individual
Priority date: 1942-12-02
Filing date: 1942-12-02
Publication date: 1948-04-20
Anticipated expiration: 1965-04-20

Description

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Panarea Apr. zo, 194s` UNITED STATES PATENT vOFFICE y 2.43am j Y maar cLu'rcn can Wesley Porter, Alexandria. vn. Appucauon December z, 1942, serial No. 461,659

s claims. (camz-30.5) l

(Granted under the act of March 3, 18783, as

The invention herein disclosed is ameans Ior increasing the speed and personal safety and reducing manual fatigue of the operator in driving nuts` or other rotarily wedged parts into place or loosening them therefrom after they have been tightened.

The main object of the invention'is to adapt the use of power means for supplying both intering intermittent impulses thereto, and vice versa.,

said means being operative automatically upon increase in resisting torque due to tightening of the nut or decrease in the resisting torque due to loosening thereof, respectively, the change-over being effected at a torque value in accordance with the speed of the power motor, said means -iurther automatically increasing the energy supplied per impulse during intermittent operation as well as increasing the number of impulses upon increase in speed of rotation of the power motor.

In the accompanying drawings, two preferred forms of my invention are shown as arrangement A, and arrangement B. Figs. 1 to 5 illustrate arrangement A and Figs. 6 to 9 illus- In'the drawings:

Fig.v 1 is an elevation of an assembly of the wrench according to arrangement A, illustrating its application to a nut. and cut away to show Y the principal parts of the invention.

. arrangement "B," illustrating its application to a nut. and cut away to show the principal parts of the invention,

Fig. 'Z is a transverse cross-section taken at the section line 1-1 of Fig. 6, l

Fig. 8 is a transverse cross-sectionof the torque block I taken at the section line 8-8 of Fig. 6,

amended April 30, 1928; 370 0. G. 757) Fig. 9 is a transverse cross-section taken at section line 9.9 of Fig. 6.

It is my aim to provide an impact wrench attachable to a source ci power (electricor corn-y pressed air) and so operable therefrom that this` wrench may through its component parts, be used to impart blows or impacts to a nut in Vsuch a way as to turn or rotate the nut fortightening or loosening purposes.

I-t 1s i'urther my aim to combine in this same tool, means for' simple high-speed spinning, of nuts on or oi! bolts, whenever the nut ts loose enough to permit such operation.

The advantages of this wrench over other tools for this purpose are its compactness. simplicity. effectiveness, eiciency, safety. smoothness of operation, speed and lack of fatigue with which my wrench can be operated.V

Operation "A Referring to arrangement "A," Figs. 1 to S on E splines 1. 1, etc., engaging impact. transmtting rolling elements 8, 8, etc., such as balls orl the like, and driving them. 9, 9, etc., are splines in the torque block concentrically placed with reference to splines 1. 1, etc., and are so placed as to engage and be impacted by the balls 8, 8, etc.

I0 is a square projective end-post on the impacter5.

II is a disc for place. I2 is a square hole in II for tting over the square end-post I0. I3 is a coupling or sleeve, I4 being a square hole running axially through the center of sleeve I3. I5 is a square projective end-post on drive shaft I6 for driving` the impacter 5 by common engagement there` with by means of sleeve I3 and end-post III.

I1 is the casing enclosing the various parts as shown and forming part of the body of the assembly. I8 is a bail bearing assembly shown for illustrative purposes, it being recognized that the bearing details and actual location are subjectV to variation.`

I9 is the casing or body of the motor which drives the rotating parts of the tool. wrench handle. 2l is the motor operating trigger remaining bans s, s, etc., m'

20 is the Y or switch, 22 is a. hose orcaible connection. these parts being shown for illustrative purposes only. 23 is a flange on the casing I9, 24 is its companion on casing I1. 25, 25, etc., are assembly bolts, and 26 is a spacer between anges 23 and 2l. 21 is a socket wrench and 28 any nut it is desired to turn on any bolt 29 holding some part 30 to any other part.

The operation of my device is as follows: Referring to Fig. 1 and assuming 28 is a nut which it is desired to turn on bolt 29, and that the wrench is attached to a source of power as at 22, the operator may select the proper size socket wrench 21 and piace it on the projective end-post 3 and then engage wrench 21 with nut 28. Then,

by pressing the trigger 2| the motor will start up and revolve drive shaft I8, and consequently the impacter 5, this part being positively engaged with shaft I8 through end-post I5, sleeve I3-and end-post I8. Referring to Fig. 2 assume balls 8. 8, etc., are at the bottom of the openings between

splines

1, 1, etc., i. e., nearest the axis of rotation of the impacter 5. As soon as the impacter comes up to a certain speed, balls 8, 8, etc., will be thrown outward by centrifugal force until they drop into the slots between splines 9, 9, etc., in the torque block. However, the balls cannot get out of reach of

splines

1, 1, etc., and will therefore be driven in a circular path inside the torque block until they impact splines 8, 9, etc. At this instant the balls are in shear between

splines

1, 1, etc., and splines 9, 9, etc. The Wedging action thus produced on the balls will, due to their position with relation to the respective splines, force the balls back toward the center of rotation, and thus out of engagement with splines 9, 9, etc., whereupon 5 will regain anyspeed lost and above cycle of events will be repeated. This cycle will be repeated at a rate depending on the speed of the driving motor. A major part of the force of impact of the balls with the splines 9, 9, etc., will be transmitted through the torque block to the wrench and the nut 28, which will be broken loose if it is frozen and rotated. The looser the nut becomes, the faster it will be driven, iinally approaching the speed of the driving motor.

The nut 28 may be turned in a direction opposite to that above described simply by reversing the motor.

The depth of the grooves formed by the splines 9 on the outer members is less than the radius of the balls '8, whereas the depth of the grooves formed by the splines 1 on the inner member is slightly greater than the diameter of the balls 8. The edges of the splines 1 on the inner member are formed with sharp squared corners against which the balls 8 will be wedged at the time of impact.

Arrangement "B The aims as set forth above apply for arrangement B, and in addition thereto it is my aim to provide in arrangement B a means for more positively locking the driving and driven members of the wrench together in order to cause the driven member to rotate at the same speed as the driving member without impacts, whenever the nut being turned is lose enough to permit. It is further my aim to provide a means for causing the change-over from impacting the nut to full speed rotation of the nut and vice versa automatically.

The advantages of arrangement B are the same as mentioned above, and in addition thel'eto, the positive locking feature of arrangement B has the further advantage of greater speed and emciency under certain operating conditions.

Referring to arrangement "B." Figs. 6 to 9 on the accompanying drawings, I is a cylindrical torque block; 2 is a cylindrical impacter or bali driver; 3, 8, etc., are impact transmitting balls;

l, 4, etc., are slots or pockets in the impacter 2 for holding and carrying the balls: 5, 5, etc., are companion slots or pockets in the torque block for receiving the balls; 6 is a cylindrical bore in the torque block of smaller diameter than 1 which is also a cylindrical bore in I. The centers of both bores coincide with the center of rotation of the torque block and the impacter. 8 is a square hole in the torque block, centrally located in the outer end thereof. 9 is a cylindrical bearing surface at the outer end of the torque block. I8 is a square projective end-post of socket wrench I I, and serves to engage the torque block positively in the square hole 8 and is a snug nt therein. I2 is any nut to be turned, and is shown for illustrative purposes only.

I3 is the greater cylindrical section of the impacter 2, being of slightly smaller'diameter than bore 1 for clearance. I4 is the greater cylindrical section of the torque block. I5 is a square endsection of drive or motor shaft I6. I 1 is a shoulder or collar on shaft I8, forming the inner seat for coil spring I8, I9 being the outer seat which is freely slidable axially on section I5. 2l) is a square hole centered axially through the impacter for engaging section I5, making the impacter freely slidable axially on said section.

2i is the outer casing of the assembly of parts as shown, and forms part of the body of the wrench. 22 is the motor casing or frame. having handle, power attachment, trigger, etc., as 20, 22 and 2i in arrangement A," Fig. l. 23, 23, etc., are bores for receiving assembly bolts like 25 in arrangement A, Fig. 1; 24 and 25 are bearing assemblies shown for illustration, possible variation in their details and locations being recognized. 28 is a grease packing and dirt seal.

29 is any bolt engaged with nui-I I2 for the purpose of holding any part 30 to any other part, these parts being shown for illustrative purposes.

The operation of arrangement B of my invention isas follows: Assuming that the tool is attached to a source of power, and the socket wrench II is in place on nut I2, the operator may press the trigger and start the motor, whereupon shaft IG will be rotated, and consequently the impacter 2. Spring I8 and seat I9 will likewise be rotated. If the nut I2 resists turning sumciently, wrench II and consequently torque block I will resist also.

At this point halls 3, 3, etc., will be in shear between the opposing edges of the slots or grooves l, I, etc., and 5. 5, etc., and there will be a wedging action set up by the balls being forced out of

grooves

5, 5, etc. Consequently, the impacter will slide on section I5 away from the torque block I. and seat I9 will move with the impacter, and the spring will be compressed. The depth and shape of the grooves are such that due to the limited axial movement of the impacter, the balls will be forced to leave the

shallower grooves

5, 5, etc., but remain in the deeper grooves I, I, etc., moving with the imtorque block will be accelerated. However, as soon as the balls have been rotated to a position opposite the neXt forward set of

grooves

5, 5, etc., they will be rammed into these grooves by the force of the spring i8 assisted by the centrifugal force of the balls due to their rotation. The impact of the balls on the leading ments and extending in a direction having a radially outward component, all said deeper not more than 90 degrees so that upon sufficient pressure being exerted on a rolling element caught in the end of one of said other grooves edges of

grooves

5, 5, etc. will rotate the torque block and therefore the nut I2.

The above cycle of events will be continuously repeated at a rate proportional to the speed of rotation of the drive shaft I6, until the nut is loose enough to turn with the torque block without impacts, after which the pressure of the spring I8 will hold the balls in the

grooves

5, 5. etc., and all the elements will rotate together at the speed of shaft I6.

If it is desired to turn nut I2 in the direction opposite to that above described, the operator may simply reverse the motor, and the above described cycle of events will take place just as before, except in the proper order for reverse rotation of the nut.

It is to be understood that the above devices represent but two forms of the invention which includes all other forms and obvious modifications Within the scope of the claims appended hereto. A third form is shown and claimed in Patent No. 2,399,251 issued April 30, 1946, as a division of this patent.

The invention described herein may be manufactured and used by or for the Government of the United States for governmental purposes without the payment to me of any royalties thereon or therefor.

What I claim is:

1. In a reversible variable speed power tool for turning, tightening and loosening parts; a coupling between the driving and driven members comprising a pair of aligned rotatable members attached respectively thereto and having closely adjacent opposed circumferential surfaces, there being a similar seriesv of grooves equally spaced around the circumference of each of said surfaces,van anti-friction element for each of the grooves in one of said surfaces, the latter grooves being of a depth sufcient to contain the anti-friction elements, the other grooves being slightly less than half of such depth, said deeper grooves having sharp edges for simultaneously snapping all the elements out of their shallow grooves in cooperation with the opposed end edges thereof.

2. In a reversible variable speed power tool for turning, tightening and loosening parts, a coupling between the driving and driven means comprising a pair of aligned rotatable members attached respectively thereto and having closely adjacentl opposed surfe/ces of revolution, there being similar series of grooves equally spaced around the circumference of each of said surfaces, a rolling element for each of the grooves in one of said surfaces, the latter grooves having a depth extending in a direction having a radially inward component, the other grooves having angular sides which sides are also angular to the adjacent sides of the next adjacent grooves and are slightly less than half the depth equivalent to the diameter of said rolling eleby the edge at the end of the .opposed groove, the said rolling element will be caught invshear between the sharp edge of said other groove and the angular side of said opposed groove and thereby will be snapped out of the said other groove into the opposed one and thus the two surfaces will move relative to each other after imparting a sharp impact to the driven member.

3. The combination of claim 2 wherein the surfaces of revolution are parallel to the axis of rotation.

4. The combination of claim 2 wherein the surfaces of revolution are parallel to the axis of rotation and the groovesin the inner member are deep enough to contain the rolling elements.

5. In a reversible variable speed power tool for turning, tightening and loosening parts; a coupling between the driving and driven members comprising a pair of aligned rotatable members attached respectively thereto and having closely' adjacent opposed circumferential spr faces, there being a similar series of grooves equally spaced around the circumference of each of said surfaces, an anti-friction element for each of the grooves in one of said surfaces. the latter grooves being of a slightly greater depth than the diameter of the anti-friction elements, the other grooves being of a depth slightly less than the radius of said elements, all of said latter grooves having sharp edges at their ends.

6. In a reversible speed power tool for turning, tightening and loosening'parts; a coupling between the driving and driven members comprising a pair of aligned rotatable members attached respectively thereto and having closely adjacent opposed surfaces of revolution,y there being a similar series of grooves equally spaced around the circumferenceof each of said surfaces, a rolling element for each of the grooves in one of said surfaces, the latter grooves being of a depth sufllcient to contain said rolling'elements.

the other grooves being slightly less than half of such depth, all said latter grooves having sharp edges at their ends.

Y CARL WESLEY PORTER.

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

UNI'I'ED STATES PATENTS