US3514990A

US3514990A - Tool adjustment device

Info

Publication number: US3514990A
Application number: US691442A
Authority: US
Inventors: Paul D Bauknight; Robert Lahrheim
Original assignee: Thomas and Betts Corp
Current assignee: ABB Installation Products Inc
Priority date: 1967-12-18
Filing date: 1967-12-18
Publication date: 1970-06-02
Anticipated expiration: 1987-06-02

Description

June 2, 1970 P. D. BAUKNIGHT ET AL 3,514,990

TOOL ADJUSTMENT DEVICE 2 Sheets-Sheet 1 Filed Dec. 18. 1967 PRIOR ART FI.l

-FIG.2

INVENTORS PAUL D. BAUKNIGHT ROBERT LAHRHEIM ATTORNEY June 2, 1910 P, D, BAUKNIGHT E'l AL 3,514,990

TOOL ADJUSTMENT DEVICE Filed Dec. 18, 196'? z Sheets-Sheet 2 l GD "h "1 S r Ii h 36 80 I0 INVENTORSI 7 PAUL D. BAUKNIGHT n ROBERT LAHRHEIM wikqdwwl ATTORNEY United States Patent 3,514,990 TOOL ADJUSTMENT DEVICE Paul D. Bauknight, Cranford, and Robert Lahrheim, Colonia, N..I., assignors to The Thomas & Betts Co., Elizabeth, N.J., a corporation of New Jersey Filed Dec. 18, 1967, Ser. No. 691,442

Int. Cl. 821d 7/06 US. Cl. 72-410 6 Claims ABSTRACT OF THE DISCLOSURE This disclosure is directed to a tool adjustment device and more particularly an adjustment device for operation 'with the full-stroke compelling mechanism. The disclosure provides an adjustment device to compensate for the build-up and varying tolerances of hand tools having fullstroke compelling mechanisms. In order to insure that the full-stroke compelling mechanism will release at the proper point in the compression cycle the disclosure provides an adjustable pawl cooperating with the rachet of the full-stroke compelling mechanism. The pawl is mounted upon an eccentric pawl pin which may be rotated in order to position the pawl adjacent the desired land, or tooth, of the full-stroke compelling mechanism ratchet. Locking means are provided to lock the pawl to the eccentric pawl pin to prevent relative motion therebetween. The eccentric portion of the eccentric pawl pin is provided with range of eccentricity between the best and worst case conditions so that the tool may be continually readjusted to compensate for variances in the size of the crimping dies and tolerance variations occurring during manufacture and dimensional changes due to wear of the various operative portions of the crimping tool.

BACKGROUND OF THE INVENTION Field of the invention The invention is directed to the field of tools having full-stroke compelling mechanisms to permit their continuous readjustment to compensate for variations in the tool operation caused by manufacture and wear. Although, in the specific embodiment to follow, the tool adjustment device is directed to a hand tool of the toggle type having a full-stroke compelling mechanism it is similarly applicable to electrically, pneumatically, hydraulically and other tools operated by similar means which similarly have full-stroke compelling mechanisms.

Description of the prior art Prior art hand tool of the toggle type are represented by devices of the type shown in US Pat. 2,696,747, issued Dec. 14, 1954, to Martin D. Bergan for a Toggle- Actuated Crimping Tool With Full-Stroke Compelling Mechanism, owned by the assignee of the instant invention. This device employs a fixed pawl which is preset at the factory at the time of tool assembly and cannot be adjusted in the field. This was done partially to prevent the insertion into the tool of dies or other devices for which the tool was not designed to handle and which otherwise might impair its operation. Errors in the registration of the pawl with respect to the ratchet of the full-stroke compelling mechanism can only be handled by sending the tool back to the manufacturer and having the pawl removed therefrom and replaced by another pawl or having the pawl ground down to properly meet the desired point of the rachet of the full-stroke compelling mechanism. Such procedures are time consuming and expensive, requiring that the tool be returned to the manufacturer during which time it is lost to the user.

3,514,990 Patented June 2, 1970 SUMMARY OF THE INVENTION The present invention overcomes the difiiculties noted above with respect to the prior art devices by providing a pawl arrangement which is adjustable and can be reset in the field at any time in order that the pawl properly mate with the rachet of the full-stroke compelling mechanism. This is achieved by replacing the fixed pawl pin, found in the prior art device noted above, with an eccentric pawl pin and mounting thereon a pawl having a locking mechanism such that the pawl may be positioned upon the eccentric pawl pin and the eccentric pawl pin rotated in order to bring the tip of the pawl into the proper location with respect to the rachet of the fullstroke compelling mechanism and then locked in such position. The locking means may at any time be selectively unlocked to permit the pawl to be moved upon the eccentric pawl pin such that the desired location can be reestablished despite wear and accumulated tolerance build up in the tool through use. It is therefore an object of this invention to provide an improved form of tool adjustment mechanism.

It is another object of this invention to provide an improved form of tool adjustment mechanism for use with a full-stroke compelling mechanism.

It is another object of this invention to provide a tool adjustment mechanism for use with a full-stroke compelling mechanism which can be continually adjusted to compensate for changes in the tolerance and cooperation of the various portions of the associated tool.

It is still another object of this invention to provide a tool adjustment device for operation with a full-stroke compelling mechanism which can be selectively adjusted with simple, available tools.

It is yet another object of this invention to provide a tool adjustment device for operation with a full-stroke compelling mechanism which comprises a pawl, selectively lockable upon an eccentric pawl pin which can be selectively rotated in order to position the pawl with respect to the rachet of a full-stroke compelling mechanism.

Other objects and features of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of example, the principle of the invention, and the best mode which has been contemplated for carrying it out.

BRIEF DESCRIPTION OF THE DRAWING In the drawings:

FIG. 1 is a vertical sectional view of the tool shown and described in the above cited Bergan patent and which represents the prior art.

FIG. 2 is a side elevation of a modification to the dies employed with the tool of FIG. 1.

FIG. 3 is an isometric drawing of a pawl and eccentric pawl pin constructed in accordance with the concepts of the invention.

FIG. 4 is an isometric view, of the tool of FIG. 1, with a portion of the outer body removed in order to clearly show the cooperations between the eccentric pawl pin, the pawl and the rachet of the full-stroke compelling mechanism.

FIG. 5 is a side elevation of the tool of FIG. 1 illustrating the position of the adjustable mechanism prior to the beginning of the operation stroke.

FIG. 6 is a side elevation of the tool of FIG. 5 illustrating the position of the pawl during the operating cycle.

FIG. 7 is a side elevation of the tool of FIG. 5 showing the position of the pawl upon release of the fullstroke compelling mechanism.

Similar elements are given similar reference characters in each of the respective figures.

DESCRIPTION OF THE PREFERRED EMBODIMENT Turning now to FIG. 1 there is illustrated a toggle type crimping tool with a full-stroke compelling mechanism as found in the prior art. This figure is FIG. 6 of the above cited Bergan patent which patent is incorporated herein by reference. Details of the Bergan patent which are common with the tool of the instant invention will not be described again for the sake of simplicity. Pawl 39 is mounted upon pawl roll pin 40 and is biased to an initial position by means of the spring 43 connected between pin 44 and arm 45 of the pawl 39. The position of the pawl with respect to the handle 14 is maintained by means of the pawl spacers 41. The pawl nose 42 is arranged to engage the teeth and lands of the rachet 35 and after completion of a full-stroke is permitted to move into the rear clearance area 36. The positioning of the pawl 39 with respect to the rachet 35 is determined by the shape of the nose 42, the overall shape of the pawl 39 and the position of the pawl roll pin 40. Once these positions have been established and the shape of the pawl established it is not possible to readjust the device for wear at the various rotation points such as the fulcrum 37, the pin 13 or pin 33. It is necessary, due to wear at these points or at the

dies

17 and 18, that the shape of the pawl 39 be altered by grinding or by providing a new pawl 39 which will permit the desired method of operation.

Turning now to FIG. 2 the opposite side of the tool of FIG. 1 is shown. This figure illustrates a modification made to the die set which permits gauging of the dies as will be described below. Replaceable die element 17 has been replaced by another die element 17' having an extended shoulder 50. The shiftable jaw 18 has been replaced by a further shiftable jaw 18' which a so has an extended shoulder 52. -In the position shown in FIG. 2, extended shoulder 50 of the replaceable die element 17' and the extended shoulder 52 of the shiftable jaw 18 are in engagement with one another in what is called the gauging position. This position is one in which go-no go gauges may be inserted between the indenters 30 and the nets 29 of the replaceable die element 17' in order to determine the proper crimping clearances therebetween. This will be described below with reference to FIG. 4. The gauging position is the position of maximum engagement of the replaceable die element 17 and the shiftable jaw 18' at which point the adjustable pawl arrangement to be described below is in engagement with a preselected portion of the rachet 35.

Turning now to FIG. 3 there is shown a pawl and an eccentric pawl pin constructed in accordance with the concepts of the invention. Pawl 60 has a nose 61, a straight face 62, an inclined face 64, a plane face 66 approximately parallel with face 62 and a further inclined face 68. In the face 66 is placed a tapped hole 70 for the reception of a set-screw 72 or the like. At the approximate jointure of the

faces

62 and 64, the body of the pawl 60 has a decreased thickness area 74 with an aperture 76 placed therein. In the body of the pawl 60 is the eccentric pawl pin receiving aperture 78. The spring 43, as shown in FIG. 1, will be attached through the hole 76 for positioning the pawl 60 with respect to the ratchet 35. The hole 78 will be used to receive the eccentric pawl pin therethrough to couple the eccentric pawl pin with pawl 60 in rotatable relationship with respect to the rachet 35.

The pawl pin 80 has a first bearing section 82 rotatably positioned within a portion of the body of the tool 10 (not shown). A further bearing section 84 is provided for rotatably mounting within the body of the tool 10 (not shown). A C-ring or similar fastening device (not shown) will be positioned in the slot 86 once the eccentric pawl pin has been positioned within the tool 10 to prevent the eccentric pawl pin 80 from being removed from the tool body accidentally.

Bearing sections

82 and 84 are positioned along the same center line. An eccentric section 88 is coupled between and to the bearing

sections

82 and 84. Its center line is different than that of the center line of bearing

sections

82 and 84 thus giving rise to the eccentricity. Slot 90 is provided in the face of the bearing section 82 to permit rotation of the eccentric pawl pin 80 with respect to the body of the tool 10. The pawl 60 will be positioned upon the eccentric section 88 of the eccentric pawl pin 80 when installed in the tool 10 and the pawl 60 will be locked to the eccentric pawl pin 80 by means of a fastener 72. In this manner, relative rotation between the eccentric pawl pin 80 and the pawl 60 is not possible. However, pawl 60 will be permitted to rotate with rotations of the eccentric pawl pin 80.

Turning now to FIG. 4 there is shown a fragmentary portion of the tool 10 illustrating the positioning and operation of the pawl 60 with respect to the rachet 35. With the replaceable die element 17 and the shiftable jaw 18 in their gauging position, that is with the

shoulder extensions

50 and 52 respectively in contact with one another, the nose 61 of the pawl 60 will contact the land between the two

final teeth

35a and 35b of the rachet 35. The application of a slight, further squeezing pressure to the legs 14 and 15 (not shown) of the tool 10 will cause the pawl 60 to go beyond the tooth 35]; thus releasing the pawl 60 and the full-stroke compelling mechanism. It is essential that the nose 61 of the pawl 60 be in the position noted between the

teeth

35a and 35b for the proper operation of the device. In order that the replaceable die element 17 and the shiftable jaw 18 be properly positioned at the gauging position, to permit the insertion of gauges to determine the clearances between the indentors 30 and the nests 29 the tool must be locked at this point. If the nose 61 of the pawl 60 is not in the desired position too much attentional pressure would be required to cause the pawl 61 to go beyond the tooth 35b into the rear clearance area 36 of the rachet 35. Such additional force could not be applied due to the butting of

shoulder extensions

50 and 52. Therefore, it would not be possible to bring the tool to the gauging position and then to release it. Further, if the nose 61 of the pawl 60 was beyond the tooth 35b in the rear clearance area 36 it would not be possible to lock the tool in a gauging p0- sition thus to determine the desired spacing. Although the nose 61 of the pawl 60 could initially be set in the desired position as is done with the tool of the prior art wear at the various crucial points such as 33 and 13 and that the pin itself upon which the pawl 60 is mounted as well as wear at various other pivotal points in the device and at the extended shoulder dies could cause this initial set position to be in error. According to the instant invention, with the dies set in the gauging position the pawl nose 61 of the pawl 60 can be positioned to the desired location between the

teeth

35a and 35b of the rachet 35 simply by loosening the fastener 72 rotating the eccentric pawl pin 80 by means of a screw driver or other similar device inserted into the slot 90 of the eccentric pawl pin 80. After the eccentric pawl pin 80 has been rotated to the desired position, positioning the nose '61 of the pawl 60 at the desired location the fastener 72 may be tightened to prevent relative movement between the pawl 60 and the eccentric pawl pin 80. In FIG. 5 the location of the pawl 60 prior to the start of the compression operating cycle is shown. The

handles

14 and 15 are separated causing the separation of the replaceable die element 17 and the shiftable jaw 18'. At this point a crimpable connector and a conductor to which the connector is to be assembled may be placed in the nest 29 of the replaceable die element 17.

The nose 61 of the pawl 60 is now to the extreme left of the ratchet 35 and fails to engage any of the teeth thereof. As pressure is applied to the

handles

15 and 14 the rachet 35 begins to sweep over the nose 61 of the pawl 60 from the initial position established by the spring 43. The movement of the upper handle 15 towards the lower handle 14 causes the rachet 35 to travel in a direction generally shown by the arrow in FIG. 6. In the squeeze operation the nose 61 of the pawl 60 will be moved out of position causing it to engage the teeth of the rachet 35. Any release of the pressure applied to the

handles

14 and 15 will cause the nose 61 of the pawl 60 to immediately engage a tooth of the rachet 35 and prevent the tool from opening as is shown in FIG. 6. In this manner, once the pawl 60 has engaged the rachet 35 it is necessary that the complete compression cycle be run through to insure that a good crimp is produced etween the connector and the conductor before release of the tool. Continued compression of the

handles

14 and 15 will cause the replaceable die element 17' and the shiftable jaw 18' to move towards one another until they reach the gauging position, as shown in FIG. 4, at which time the nose 61 of the pawl 60 will be between

teeth

35a and 35b of the rachet 35. A slight additional pressure, applied to the

handles

14 and 15, will permit some flexing of the end of the member 11 to permit the rachet 35 to be advanced so that the pawl 60 can move past the tooth 35b and into the rear clearance 36 as shown in FIG. 7. At this point the full-stroke compelling mechanism is cleared and the device tool may be opened at will.

As was noted above limited flexing of the end 16 is permissable and is possible with the device. However, the amount of flexure is limited and thus the gross mispositioning of the nose 61 of the pawl 60 could not be accommodated by the flexure of the end 16 and thus the tools full-stroke compelling mechanism would not be released. Further, a mispositioning in the other direction, that is past tooth 35b towards the rear clearance 36 causes the tool 10 to be opened too quickly and thus would not lock at the gauging position as is desired.

With the adjustable mechanism described herein it is possible to change the location of the pawl with respect to the rachet teeth to accommodate changes due to wear in the extended shoulders of the dies or wear in the various pivotal points of the tool. Further, it is also possible now to accommodate changes in the replaceable die element and still have the desired full-stroke compelling mechanism operate.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to the preferred embodiment it will be understood that various omissions and substitutions and changes of the form and details of the device illustrated and in its operation may be made by those skilled in the'a-rt, without departing from the spirit of the invention.

The embodiment of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a crimping tool of the toggle-type having a full-stroke compelling rachet mechanism, the improvement comprising an adjustable pawl arrangement comprising: a pawl; an eccentric pin coupling said pawl to the body of said tool adjacent the full-stroke compelling rachet; spring means coupled between the body of said tool and said pawl to bias said pawl to an initial position; and locking means coupling said pawl to said eccentric pin to prevent relative movement between said pawl and said eccentric pin; said locking means permitting the locking of said pawl to said eccentric pin after said pawl has been positioned adjacent a desired portion of said rachet.

2. An adjustable pawl arrangement as defined in claim 1, further including adjustment means coupled to said eccentric pin for rotatably positioning said eccentric pin with respect to said rachet.

3. An adjustable pawl arrangement as defined in claim 1, wherein said eccentric pin comprises: a first bearing section arranged to be rotatably mounted in a first aperture of said tool body; a second bearing section ar ranged to be rotatably mounted in a second aperture of said tool body; said first and second bearing sections having a common center line; and an eccentric section coupled between and to said first and second bearing sections; said eccentric section having a center line different than that of said first and second bearing sections.

4. An adjustable pawl arrangement as defined in claim 3, wherein said eccentric means further includes adjustment means for rotatably positioning said eccentric pin with respect to said rachet.

5. An adjustable pawl arrangement as defined in claim 1, wherein said locking means is a screw member which can be selectively operated to couple or uncouple said pawl to said eccentric pin, whereby said pawl can be repositioned adjacent said rachet as required.

6. An adjustable pawl arrangement, as defined in claim 3, further including retaining means coupled to said eccentric pin, for retaining said eccentric pin, in said tool body while permitting rotation of said eccentric pin.

References Cited UNITED STATES PATENTS 104,426 6/1870 Clark 81-406 556,394 8/1900 Deiters 81406 2,696,747 12/1954 Bergan 72410 2,738,693 3/1956 Logan 72-410 2,933,000 4/1960 Wood 72410 3,406,558 10/1968 Tillmann 72-416 CHARLES W. LANHAM, Primary Examiner G. P. CROSBY, Assistant Examiner US. Cl. X.R.

53 5 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION atent 3,514,990 Dated June 2, 1970 Paul D. Bauknicrht and Robert Lahrheim identified patent shown below:

Inventor(a) It is certified that error appears in the aboveand that said Letters Patent are hereby corrected as Column 4, line 40, delete "attentional" and insert additional sen-m EAL) Attest:

mm 1:. w 1 R- EdMM-mm'h Commissioner of Patents Atteudngoffioer