US 2736220 A
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Description (OCR text may contain errors)
Feb. 28, 1956 J. KAMUK BOLT-HOLDING WRENCH Filed Sept. 13, 1954 zlllll mhnr IIIII INVENTOR. J'amvjmuz:
United States Patent BOLT-HOLDING WRENCH John Kamuk, Van Nuys, Calif.
Application September 13, 1954, Serial No. 455,501
1 Claim. (Cl. 8155) The invention relates to a wrench assembly for use in tightening the brake bands in automotive transmissions of the automatic type.
The principal object of the invention is to provide a wrench assembly which can be utilized on all of the presently known types of automatic transmissions in all of the different makes of passenger type automobiles.
Another object of the invention is to provide a wrench having novel means for holding a removable wrench socket thereto.
Another object of the invention is to provide a wrench having a novel counting mechanism incorporated therein.
Other objects and advantages of the invention will be apparent from the ensuing specifications and appended drawing in which:
Fig. l is a side elevational view of the wrench assembly;
Fig. 2 is a schematic view showing a portion of the wrench assembly as it is being utilized to tighten the brake band of an automatic transmission;
Fig. 3 is a fragmentary detail sectional view taken on the line 3-3 of Fig. 1;
Fig. 4 is a sectional view taken on the line 4-4 of Fig. 1;
Fig. 5 is an enlarged fragmentary sectional view of the counter mechanism portion of the wrench assembly;
Fig. 6 is a sectional view taken on the line 66 of Fig. 5;
Fig. 7 is a sectional view taken on line 7--7 of Fig. 5;
Fig. 8 is a fragmentary sectional detail view taken on the line 8-8 of Fig. 5 showing different gear positions schematically; and
Fig. 9 is a fragmentary sectional detail view taken on the line 99 of Fig. 5.
.In general the wrench assembly includes the outer socket accommodating wrench A which has its barrel telescopically positioned on the shank of the inner wrench B, the upper end of which is provided with a socket for accommodating a torque wrench C for accurately measuring the torque which is applied to the shank of the inner wrench B. Referring to Fig. 2 the socket portion of the outer Wrench is utilized for loosening the lock nut D preparatory to effecting adjustment of the adjustment screw E with the inner wrench, after which the socket on the outer wrench is again utilized to re-tighten the lock nut so as to lock the adjustment screw in its newly adjusted position.
The outer wrench includes a barrel 2 which has a cylindrical bore 3 extending entirely therethrough "At the lower end of the barrel a reduced portion 4 is provied, being of square section externally to accommodate a conventional wrench socket 5 which is removably secured to the extension 4 by means of the wire spring member 6 which exerts a lateral tension against one corner 7 (see Fig. 4) of the wrench socket 5, the tension being sufiicient to retain the Wrench socket on the extension 4 but permitting ready removal of the same. A hole 8 (see Fig. 3) is drilled into the end of the barrel 2 along the length of one corner of the extension 4 so as to provide the ice 2 notch 9 throughout the length of the extension 4. The length of wire 6 is normally bowed considerably before its inner end 11 is pushed into the bore 8 and the outer end remains permanently bowed as indicated in Fig. 3, however, the outer end is free to spring inwardly within the groove 9 as the wrench socket is pushed onto the extension 4.
The barrel 2 has a lateral bore 13 into which the wrench handle 14 is received with a press-fit and the upper end of the barrel has a reduced portion 15 providing the annular radially extending shoulder 16 for accommodating the annular collar 17 which is rotatably received on the reduced portion 15 of the barrel. A cap 18 has an internal bore 19 through which the shank 20 is loosely or rotatably received and a counterbore 21 receives the upper end of the reduced portion of the barrel and is rotatable relative thereto, however, it may be secured thereto against axial displacement by means of an annular snap ring 22 received in appropriate annular grooves formed in the barrel and cap respectively. A second counterbore 23 has a single tooth accommodating notch 24 (see Fig. 6) in its internal circumference, the reason for which will be explained hereinafter. The annular cup member 17a serves as a protective shield.
Collar 17 has the axial bore 25 through which extension 15 projects and a number of internal teeth 26 (preferably 20 of these teeth) are formed on the collar 17 and these internal teeth are permanently in mesh with the lower complement of teeth 27 on the compound gear which is referred to generally by the numeral 28. A notch 29- is cut in the wall of the barrel extension 15 to accommodate the compound gear, the gear being fiXed to its axial shaft 30 the opposite ends of which are received in appropriate bores in the barrel 2. The gear is rotatable relative to the barrel 2. The cap 18 is normally loose on the shank 20 of the inner wrench and a retractable plunger 31 has a head 32 which is reciprocable within a radial bore 33, the head preferably being serrated to engage the serrated portion 34 of the inner wrench shank to cause the cap 18 to be rotated along with shank 20 as desired. 'A compression spring 35 normally urges the head 32 toward shank 20, however, the transverse pin 36 which is secured to the plunger shank normally engages the outer wall of the cap 18 to retract the plunger against the compression of the spring 35 away from contact with shank 20, the knob 38 being rotated degrees to permit the pin 36 to drop into the notches 39 (see Fig. 9) thereby permitting the spring to move the head 32 into engagement with shank 20 so that the cap 18 will be rotated along therewith. The bevelled external wall of collar 17 and cap 18 are provided with the numerals 40 and 41 respectively to record the number of times that the shank 20 is rotated relative to the barrel 2.
In the operation of the counter mechanism one com plete revolution of the cap 18 turns the compound gear 28 degrees about its axis (there being only three teeth 42 formed on the upper end of the gear and the notch 24 in the cap 18 receiving one of these three teeth on each revolution thereof thereby rotating the compound gear 120 degrees. On each successive revolution of the cap 18, it is necessary to induce the successive tooth 42 into the notch 24 by partially rotating the compound gear at the moment when the notch 24 is approaching the appropriate position for the tooth 42 to be received therein and this partial rotation of the compound gear is accomplished by means of a pair of pins 44 and 45 which are anchored in the cap 18 and which project into the path of rotation of the lower gear teeth 27 (see Fig. 5) which are in permanent mesh with the internal gear 26 on collar 17.
It will be noted in viewing Fig. 5 that the six lower teeth project upwardly beyond the level of the flat annular 3 end face 17b of collar 17 so as to be engaged by the pins 44 or 45 the lower ends of which terminate short of end face 17b. In Fig. 5 the pin 44 is shown in a position on one-side of shank diametrically opposite gear 28 and in Figs. 6 and 8 the gear 28 has one tooth in mesh with notch 24'. Fig. 8- schematically demonstrates. the operation of the gear relative to collar 18 and assuming that the collar 18 is being rotated clockwise (viewing Fig. 8), the notch. 24 approaches gear 23 which is in the position shown in dotted lines at 28a with the upper teeth 42a and 42b riding adjacent the annular wall 23 or" collar 33 (in this condition the gear is locked against rotation about the axis of its shaft due to annular wall 23). Pin 45 engages the lower gear tooth 27aa and causes the compound gear to commence rotating at the moment notch 24 commences receiving upper tooth 4217. Continued rotation of collar 18 causes notch 24 to continue the rotation of gear 28 until the gear has been rotated 120 degrees to the new position shown in dotted lines at 28:) wherein the upper teeth are again riding adjacent annular wall 23 locking the gear 28 against rotation until collar 18 com.- pletes. a subsequent full revolution. Viewing Fig. 8 counter-clockwise rotation. of collar 13 would cause pin 44 to initiate the rotation of gear 28. There being six teeth on the lower half of. the compound gear, consequently, three of these teeth are located midway between the teeth of the three-tooth gear (as best shown in Fig. 8) these three teeth being indicated by the numeral 27a. Rotation of the compound gear 120 degrees causes the six tooth portion the gear to rotate the collar 17 throughout. an are equivalent to the distance between two teeth as. indicated by the letter F between the arrows in Fig. 7. This are is equivalent to A of a revolution of the cap 17 and it thus requires ten revolutions of the cap 18 in order to effect one complete revolution of the collar 17 thus the total number of revolutions of the shank 20 are recorded by means of the numerals on the cap 17 and the partial revolutions of the shank 20 may be readily recorded on the cap 18 by means of the numerals which are indicated by the numeral 41. If one prefers not to use the counter mechanism, it is only necessary to re tract the plunger until the pin 36' is in engagement with the outer wall of the cap 18 as shown in Fig. 5.
The inner wrench B includes the elongated shank 20 which extends through the barrel 2 and is rotatable relative thereto and movable axially thereof as desired. The upper end of the shank 20 has the enlarged portion 46 through which the handle 47 extends and the upper end thereof is provided with a socket for receiving the tongue 48 of the torque wrench C. The lower end of the shank 20 is provided with a squared end to accommodate the socket of a wrench element 49.
The method of using the wrench assembly Referring to Fig. 2 I have shown a typical application of the use of the Wrench assembly wherein the brake band 51 of an automatic automotive transmission has the radially outwardly extending spaced ears 52 and 53 maintained under tension by means of compression spring 54, said brake band being constricted when required by means of the link 55 actuated as by means of the armature 57 of a solenoid. After prolonged wear it is necessary to take up the brake band by means or" turning the adjustment. screw E a pro-determined number of turns until the desired tension. is approximately set. It is necessary to first unloosen the lock nut D, this being accomplished 4 by inserting the wrench element 49 (in this instance a screw driver tip) into the slot at the end of the adjustment screw E and then'lowering the socket 5 into engagement with the lock nut D. Then rotation of handle 14 causes the outer wrench A to loosen the lock nut D. Then while the socket 5 is held in position on the locknut D, the inner wrench B is rotated (while holding handle 14 stationary) by grasping handle 4-7, thereby tightening the adjustment screw E which acts on link 56 to eifect the rough adjustment. Then the inner wrench B is further rotated by grasping the torque wrench C and rotating the shank 29 until the torque wrench slips in a conventional manner (the torque wrench having first been initially adjusted to slip at a pre-determined torque load). Then the inner wrench B may be backed off (with reverse rotation) thereby loosening or backing off the adjustment screw E a pre-determined number of turns or partial turns (these being accurately calculated by use" of the counting mechanism hereinbefore described). Then the lock nut D is retightened by means of the outer wrench A and the entire wrench assembly is then withdrawn. away from the locknut D and adjustment screw E.
A wrench assembly for use with a combination adjustment screw and lock nut assembly comprising: a shank having one terminus for removable driving engagementwith the adjustment screw; a handle engaged with. the shank for efiecting rotation of the same about its axis; a. barrel telescopically mounted on the shank, rotatable with reference to the shank and slidable axially thereof; a wrench socket telescopically mounted on the shank, removably secure to the barrel, and arranged for removable driving engagement with the lock nut; a handle engaged with the barrel for rotating the same about the axis of the shank, whereby the lock nut may be rotated relative to the screw for loosening the same by grasping the barrel handle and rotating the barrel and the wrench socket relative to the shank, whereby the adjustment screw may be adjusted by grasping, the shank handle and rotating the shank relative to the barrel and the adjustment screw rela tive to the lock nut, and whereby the lock nut may then be retighteued relative to the screw by grasping the barrel handle and rotating the barrel and wrench socket relative to the shank, all of such operations being affected while the wrench socket remains in driving engagement with the lock nut and the terminus of the shank is simultaneously in engagement with the adjustment screw; said barrel including an extension having a longitudinally ex tending corner for engagement in a complementary recess for such corner in the wrench socket, and a bent pin fixed in the corner of the barrel for removable securing the wrench socket relative to the barrel extension.
References Cited in the file or" this patent UNI-TED STATES PATENTS 1,477,355 Jacobs Dec. 11, 1923 2,007,432 Mancuso July 9, 1935 2,235,572 Culbertson Mar. 18, 1941 2,267,012 BOWne- Dec. 23, 1941 2,599,489 Schmidt June 3, 1952 2,674,108 Latimer Apr. 6, 1954 FOREIGN PATENTS 351,090 Italy Aug. 3, 1937 569,735 Great Britain June 6, 1945