US1091937A - Tool for gripping and lifting. - Google Patents

Description

G. LEWIS.

TOOL FOR GRIPPING AND LIFTING.

" APPLIOAT-ION FILED DEG-.11, 1912.

1,091,937. I Patented Mar. 31,1914. v

f9 .'15 mum f) 1 UNITED STATES PATENT OFFICE.

GEORGE LEWIS, OF SOUTH BOSTON, MASSACHUSETTS.

TOOL FOR GRIPPING- AND LIFTING.

To all whom it may concern: Be it known that I, GEORGE LEWIS, a c1t1- zen of the United States, residlng at South Boston, in the county of Suffolk and State of Massachusetts, have invented new and useful Improvements in Tools for Gripping and Lifting, of which the following is a specification.

This invention relates to improvements in tools for gripping and lifting.

More particularly it relates to tools for seizing a pin, post or the like, on opposite sides, and extracting it from the material in which it is embedded; but the tool or suitable and simple modifications of it are applicable to a variety of other uses.

It is the object of the invention to pro: vide a tool combining a firm grip, powerful leverage, and simplicity and strength of construction with adaptability and convenience of handling and the other advantages that characterize the tool herein disclosed; and it is the object of the patent to cover such features of novelty as reside in the construction disclosed,

One embodiment of the invention is illustrated in the accompanying drawings, in which,

Figure 1 is a side elevation, with the head of the tool shown in section on the line 11 of Fig. 3; Fig. 2 is a plan of the same tool; Fig. 3 is a section of the same tool on i the line 33 of Fig. 1; Fig. 4: is a similar section of a modification; Fig. 5 represents another modification in side elevation; and Fig. 6 is a side elevation showing another way of using the tool.

In the form illustrated in Fig, 1 of the drawings, the tool is seen to be composed of a handle 10, having an enlarged portion or head, integral therewith, carrying the jaw 11, and a yoke or loop movable on the head and carrying the jaw 12 which is adapted to cooperate with jaw 11 to grip a pin 18. The yoke has two shanks 14, similar to each other, extending loosely through trunnions or gudgeons 15 carried on the head of the handle. The construction of these trunnions is seen in Fig. 3, where they are represented as being plugs held in the head by screw threads seen at 16 and having close fitting smooth bearings therein at 17. The threaded portion of each holds it in place, but when in use the trunnion is not screwed firmly to its limit, but is left projecting a little as illustrated so that it can turn freely Specification of Letters Patent.

Application filed December 11, 1912.

Patented Mar. 31, 1914.

Serial No. 736,123.

through a portion of a revolution during the natural operation of the tool as herein described. The head on which the jaw 11 is formed has shoulders 18 toward the rear, with faces that are conical about the axes of the trunnions as seen most clearly in F 1g. 3, each of which shoulders is adapted tobe engaged by a nut 19 having a concaved conical face corresponding in curvature to that of the shoulder which it is to engage, these nuts being mounted on screw threads 20 formed on the rear end of each shank 14. The under side of the head carrying the jaw 11 is shaped in a curve, leading from the handle up to the jaw and designed in a form suitable for serving as a fulcrum in prying anything up with the jaw 11.

In using the tool, the jaw 11 is placed against one side of the pin that is to be pulled and then the yoke carrying the jaw 12 1s passed over the pin, the jaw 12 brought in engagement with the other side of the pin. If necessary, in order to accomplish this, as in the case of pulling a continuous wire, or pulling a telegraph pole out of the ground; the nuts 19 may be unscrewed from the shanks of the yoke, the yoke removed from the trunnions and then re-inserted in the trunnions in position to surround the thing that is to be gripped. Both jaws having been brought into contact with whatever is to be gripped, both nuts 19 are screwed toward the shoulders 18 until they engage therewith; and the tool is then operated by pressing on the handle 20 toward whatever external support is available as a fulcrum support, 6. 9., the plank 21 in which the pin 13 is represented as set in Fig. 1. iVhen the handle is thus depressed the jaw 11 is raised. The jaw which has been drawn tight against the pin 13 by the hand operated screw nuts 19 is prevented by those nuts from receding. The pin is thus gripped bet-ween the two jaws, and the two are raised together, with the pin, as the handle is depressed, the whole tool acting as a lever turning on a fulcrum at some place on the bottom, such as, for example, the point 22. The grip quickly becomes so tight that jaw 11 cannot slip on the pin; and then both aws 11 and 12 move upward together, drawing the pin with them. During the time in which the grip is tightening on the pin and the initial slip, if any, is occurring, the trunnions 15 supporting the yoke and aw 12 turn slightly in the head on which the jaw 11 is carried. There is also some turning between the positions to which the yoke is adjusted for gripping an article of large diameter and that for one of small diameter. In the form illustrated in Figs. 2 and 3 the turning incidentally involves a slight lateral movement of the trunnibns because of the pitch of the thread 16. If the threads run in opposite directions there will be a spreading, or drawing together, but by making both in the same direction there will be merely a tendency to shift the yoke bodily sidewise a little. This may be so little that it is negligible, particularly if the thread be fine, and may be allowed for by a moderate degree of looseness of the fit of the shanks 1 1 in passing through the trunnions.

As illustrated in Fig. 3 the thread 16 is formed on the stud by which the trunnion is centered in the head, and there is another bearing surface at 17 which is smooth; but the posit-ions of this smooth bearing and the threaded bearing might be reversed if desired; and a modification is shown in Fig. 1 in which the slight lateral displacement due to the use of the threaded engagement of trunnion with the head is entirely elimi' nated. In that the bearing at 16 and that at 17 are both smooth surfaces; and the two trunnions 15 are tied together by a pin 16 which may be screwed from one into the other, being reached through a hole in the end of one of the trunnions, or preferably, and as illustrated, may be a plain double headed pin. This tie pin does not need to be especially strong, because when the tool is in use, the main twisting stresses are carried directly on the bearings 16, 17, and on the shoulders 18 and nuts 19. The pin merely holds the trunnions in place, and permits them to turn together, or separately, as circumstances require. Any tendency of the yoke to twist or spread owing to its gripping something at one end of its jaws only, or owing to other causes arising in the operation of the tool, is prevented by the concave conical formation of the faces of the nuts 19 which, engaging with the convex conical rear shape of the shoulders 17 effectually holds those nuts from spreading sidewise, somewhat on the principle of a dove-tailed joint. The tighter the draft coming through the shanks 1 1, the more tightly are the nuts 19 held inward by the oblique bearing of the nuts against the shoulder. Consequently in the construction of Fig. 4: all of the parts may be fitted with great precision and without looseness or playroom.

The modification of the invention illustrated in Fig. 5 shows a jaw 11 corresponding to that of Fig. 1, and a jaw 12 which is a repetition of jaw 11 with a handle 10 corresponding to handle 10. The shanks 14: of the yoke in this case pass through similar trunnions at each end, with similar shoulders and nuts for holding them. In

this apparatus each handle may constitute a lever; and by the use of both a tighter grip may be obtained (if such be needed in any special case) than by the form illustrated in Fig. 1 which is the form best adapted for ordinary use.

It will be understood that various modifications of the structure illustrated may be made without departing from the scope of the invention, and that the tool may be applied to a considerable variety of uses. The form illustrated in Fig. 1 is especially adapted for pulling a pin in the direction of its axis. If, however, it be desired to turn a pin around its axis that may be accomplished by the triple grip illustrated in Fig.

6, where the under surfaces 14 of the shanks 1 1 and the flank 11 of the jaw 11 cooperate with the jaw 12 to grip the pin or pipe 13. A variation of this may be made, capable of holding larger pipe, by extending the jaw 12 farther downward, in which case the pipe may either be engaged between the three flat surfaces, viz., 14:, 11, and the flank of the jaw 12, or the jaw 12 may be so long that the engagement will be the precise opposite of that illustrated in Fig. 6, viz., between 14 and the point of jaw 11 and the flank of jaw 12. When the 'tool is to be made. especially for rotating pipe, that portion of the yoke which lies between the shanks 14, as indicated at m in Fig. 1, may be omitted, thus separating the two shanks, and allowing each, with the fragment of jaw 12 remaining on it, to adjust itself on the pipe independently of its duplicate shank and jaw, the jaw 11 operating upon the pipe between the two separate jaws 12 thus formed.

As the shanks 14 are removable from the trunnions it will be'understood that a variety of shapes and sizes of jaws, adapted for various special work, may be provided, and used interchangeably. In such cases, each yoke or pair of shanks might be made to fit the same set of nuts 19. In case it is desired for any special work the shoulders 18 may be designed with a lightly cam shaped curve, as shown at 18 in the left half of Fig. 5, instead of the circular curve shown in Fig. 1, thus tightening the nuts more quickly when the yoke turns on the trunnions.

I claim:

1. A tool for gripping, comprising a lever having a head with a jaw at its end and trunnions at each side back of said jaw, a yoke having another jaw adapted to cooperate with the first; the shanks thereof passing adjustably through said trunnions and engaging back of them.

2. A tool for gripping, comprising a lever having a head with a jaw at its end, another jaw adapted to cooperate therewith and having a shank, a pivotal connection between own length through the pivot of said connection, to vary the distance of the jaws apart; and means for holding it against extension from said adjustable position.

3. A tool for gripping, comprising a lever having a head with a jaw at its end and trunnions at each side back of the jaw, another jaw adapted to cooperate with the first, shanks leading therefrom through said trunnions and adjustable in the direction of their own length, and screw nuts on said shanks engaging back of said trunnions.

4. A tool for gripping, comprising a lever having a head with a jaw at its end and trunnions at each side back of the jaw, another jaw adapted to cooperate with the first, shanks leading therefrom through said trunnions and adjustable in the direction of their own length, shoulders formed on the head back of the trunnions with faces that are conical around the axis of the trunnions and nuts on said shanks having conical faces adapted to engage said shoulders.

5. A tool for gripping, comprisinga lever having a head with a jaw at its end and trunnions at each side back of the jaw,

another jaw adapted to cooperate with the first, shanks leading therefrom through said trunnions and adjustable in the direction of their own length, and means preventing the shanks from slipping out; there being a pin located at the axes of the said trunnions and holding them in place.

6. A tool for gripping, comprising an arm having a jaw at its end; another jaw, adapted to cooperate therewith and having a shank; a pivotal connection between the shank and the arm, the shank being adjustable in the direction of its own length through said pivotal connection to vary the distance of the jaws apart; and means for holding it against extension from said adjustable position; the said shank and the two inner flanks of said jaws cooperating in triangular relation to grip a body between the three.

Signed by me at Boston, Mass, this 28th day of October, 1912.

GEORGE LEWIS.

Witnesses:

JOSEPH T. BRENNAN, MARY A. OBRIEN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0.

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