US3854354A

US3854354A - Plier type toggle wrench

Info

Publication number: US3854354A
Application number: US00417382A
Authority: US
Inventors: T Angquist
Original assignee: Cooper Industries LLC
Current assignee: Cooper Industries LLC
Priority date: 1973-11-19
Filing date: 1973-11-19
Publication date: 1974-12-17
Anticipated expiration: 1991-12-17

Abstract

A plier type toggle wrench incorporating a novel operating connection means between the wrench lever handles and the toggle link, providing an improved closed-wrench ''''holding'''' effect which is responsive to relatively small manually applied forces to effect release of the toggle holding action, while at the same time being stable when in wrench-closed condition and free from violent snap-action type opening effects.

Description

[ Dec. 17, 1974 FOREIGN PATENTS OR APPLICATIONS 610,306 12/1960 Canada......................... 81/368 Primary ExaminerJames L. Jones, Jr. Attorney, Agent, or FirmBean & Bean [57] ABSTRACT A plier type toggle wrench incorporating a novel oper- PLIER TYPE TOGGLE WRENCH Inventor: Torsten F. Angquis t, Jamestown,

Assignee: Cooper Industries Inc., Houston,

Tex.

Nov. 19, 1973 Appl. No.: 417,382

United States Patent [191 Angquist [22] Filed:

g an improved holding effect which is responsive to relatively small manually applied forces to effect re- S m 0 14 u MMMMMM .w F g .m m I ating connection means between the wrench lever handles and the toggle link, providin closed-wrench lease of the toggle holding action, while at the same time being stable when in wrench-closed condition and free from violent snap-action type opening effects.

[51] Int.

[58] Field of Search [56] References Cited UNITED STATES PATENTS 2,496,308 2/1950 Pugh et PLIER TYPE TOGGLE WRENCH BACKGROUND OF THE INVENTION Toggle wrenches of the general type disclosed for example in US. Pat. Nos. 2,280,005 and 3,710,658 have been in use for many years and have proved useful for performing a wide variety of operations, since these wrenches possess the advantages of being adjustable to accommodate many differently shaped and sized workpieces, and of being adjustable to control the amount of gripping pressure applied to the work. Further, wrenches of this type are self-locking in work-gripping position, and are thereby operable to properly hold work-pieces in clamped condition without need for continuously applied manual pressures on the wrench.

Such wrenches typically employ over-center toggle mechanisms to maintain the jaws in work-clamping position; but as a result thereof relatively large manually applied forces are required to both make and break the toggle holding action when it is desired to clamp the wrench on a work-piece and to separate the wrench from the work. Also, such wrenches tend to snap open rather violently when the toggle action is overcome, whereby such wrenches are inconvenient if not somewhat dangerous to use due to momentary loss of control of the operation by the user. These serious disadvantages of the basic type toggle wrench had led to many suggestions for improvements, such as various type force-multiplying devices designed'to assist the user in making and breaking the toggle effect; and various forms of such so-called improved toggle wrench constructions have been on the market for several years but have not provided satisfactory solutions to the above stated problems.

SUMMARY OF THE INVENTION The present invention is directed towards plier type toggle wrenches, and more particularly to an improved wrench construction which provides the proper mechanical advantages for the user when closing the wrench on a work-piece, while at the same time reducing the amount of manually applied force required to break the toggle holding effect which maintains the wrench in work-piece clamping condition. The toggle wrench of the present invention differs from the prior type toggle wrenches in the manner in which the toggle link component of the wrench is operably connected to the manually movable handle lever.

More specifically, the wrench of the present invention includes a main body or handle having at one end a stationary work-piece engaging jaw; a movable jaw pivotally mounted upon the main handle; a fulcrum device carried by the other end of the main handle in positionally adjustable relation thereon; a lever-like second handle pivotally secured to the movable jaw; and a toggle link having one end thereof coupled to the lever handle and bearing at its opposite end against the fulcrum device.

The present invention features a novel mode of restraining the toggle link member of the wrench in holding position, and from becoming accidentally dislodged therefrom; the restraining action being attained by means of a cam-sliding frictional engagement between the toggle link and the lever handle. The mechanism applies maximum strains upon the operative parts of the wrench when the wrench is closed upon a work-piece, because the toggle mechanism is then in dead-centered condition; but because of the present invention the mechanism is stabilized in this condition. Toggle wrench systems of the prior art depend upon being forced into over-center positions in order to be stabilized in work-piece holding condition. Hence, they require non-rigid toggle mechanisms and application of relatively large manually applied forces to establish and overcome their toggle-holding effects. When they are manually forced towards open" position their toggles pass over dead-center position, and then snap open; being assisted in this effect by their jaw-opening springs. In the case of the present invention the wrench may be both closed and intentionally opened more easily and smoothly by the user; unaccompanied by any violent snap-action type opening effects such as accompany the openings of prior art toggle-type wrenches.

In a preferred form of the present construction, the toggle control link is connected to the lever handle by means of a pin-and-slot connection. More specifically, as shown herein, the slot is formed in the toggle link so as to be oriented and shaped to define an inclined guide surface against which the pin (which is carried by the lever handle) bears as the toggle is being closed. Hence, the slot permits the pin to be self-centering relative to the center line of the toggle as the latter is closed incidental to frictional engagement of the cam reaction surface of the lever handle with the cam portion of the toggle link. The toggle mechanism is thereby maintained in its centered" condition by frictional engagement of the cam and the cam reactive surface, thereby preventing any unintentional opening of the wrench.

DRAWINGS The nature and mode of operation of the present invention will now be more fully described in the following detailed description, taken with the accompanying drawings wherein:

FIG. 1 is a side elevational view of a plier type toggle wrench incorporating the improvement of the present invention;

FIG. 2 is a fragmentary, enlarged scale sectional view, illustrating the operable connection between the toggle link and the lever handle when the wrench is in its open condition; and

FIG. 3 is a fragmentary view corresponding to FIG. 2, illustrating the operable connection between the toggle link and the lever handle when the wrench is closed.

DETAILED DESCRIPTION As shown by way of example in the drawing herewith, a plier type toggle wrench of the invention may be constructed to include a main handle 10 having a fixed jaw 12 carried at one end thereof; an opposed, movable jaw 14 which is pivotally mounted on handle 10 by suitable means such as a pivot pin 16; a fulcrum device 18 which is adjustably mounted on handle 10; and a tension spring 20 for normally biasing movable jaw 14 towards an open condition. An operating or lever handle 22 is pivotally mounted on movable jaw 14 by suitable means such as pivot pin 24.

A toggle link 26 is provided, and at one end thereof is movably coupled to handle lever 22 by means of a pin 28 (as will be explained more fully hereinafter) and is at its other end socketed for pivotal bearing engagement with the front end of fulcrum 18. As thus far described, the construction is essentially similar to that disclosed for example in US. Pat. No. 2,280,005.

However, the toggle wrench of the present invention departs from the prior art in that lever handle 22 and link 26 are coupled by the pin 28 carried by lever 22 in a slot 30 formed in the link 26, and in that the link and lever handle devices are formed with cooperating friction cam and

cam reaction surfaces

32 and 34, respectively. As shown in FIG. 1, the fulcrum device 18 is provided in the form of a rounded end or nose portion on a screw 36 which is threaded through the end portion of the main handle 10. Thus, manual adjustments of the positionof the fulcrum will accommodate the wrench to engagements with variously sized workpieces. Note that the slot 30 in the toggle link 26 provides the necessary freedom for relative movements of the parts when the wrench is open and/or being adjusted, while the pin 28 still operates at all times to hold the parts in assembled relation. It is of course to be understood that the cam surface of link 26 and the cam bearing surface 34 of lever 22 will be so shaped and dimensioned, and that the slot 30 will be so located in the link 26, that when the pin 28 bottoms in the slot (incidental to closing of the wrench handles) it will force the cam portion of the link 26 to slide into frictional holding bearing engagement with the inner surface 34 of the handle 22.

Thus, it will be appreciated that the frictional cam action between the toggle link member and the lever handle of the wrench of the present invention develops smoothly as the latter is moved into wrench closing position relative to the main handle. At the same time the toggle link moves into its dead center position. The toggle mechanism is thereby stabilized when in its centered position by the cam friction effect (when the tool parts are under maximum strain) whereby the invention provides an important improvement over the prior art wrenches which are highly unstable whenever they are in toggle link centered condition and are therefore awkward and inconvenient if not dangerous to use.

Thus, whereas the wrench of the present invention is stable and therefore safer when in toggle-centered, wrench closed position, in order to release the wrench from the workpiece holding condition it is only necessary to overcome the frictional coupling of the toggle link and the lever handle; the requisite force being materially less than that required to open an over-center toggle-locked type wrench of the prior art.

I claim:

1. In a wrench of the type having a main handle-like body portion provided with a fixed jaw; a movable jaw pivotally mounted upon said body; a spring normally biasing said movable jaw toward open position relative to said fixed jaw; and a toggle mechanism operable for locking said jaws in closed condition upon a workpiece, said toggle mechanism including a lever handle pivotally connected to said movable jaw and a toggle link having opposite ends thereof operably coupled to said lever handle and pivotally bearing upon a fulcrum device carried by said body;

the improvement wherein said toggle link is operably coupled to said lever handle by a pin-slot connection device and said link is provided with a cam surface arranged for engagement with a cam reaction surface portion of said lever handle when the latter is moved in one direction to a wrench-closed position and to simultaneously shift said toggle mechanism so as to arrange the pin of said pin-slot connection device substantially on the center line of said toggle mechanism whereby to frictionally lock said lever handle in said position whereat maximum jaw-locking strain is applicable upon a workpiece by the wrench parts.

2. In a wrench as set forth in claim 1, wherein the pin of said pin-slot connection device is carried by said lever handle.

3. A plier type toggle wrench having a main handle carrying a first jaw and a second jaw connected to said main handle for pivotal movement relative to said first jaw between wrench open and closed conditions; a toggle mechanism comprising a lever handle and a toggle link pivotally interconnected and manually shiftable to dead-centered condition only for locking said jaws in wrench closed position, and coacting means on said handle and said link for frictionally retaining said toggle mechanism in dead-centered condition.

4. A plier type toggle wrench as set forth in claim 3, wherein a lever handle is pivotally connected at one end to said movable jaw to provide mechanical advantage to the user when opening and closing the wrench.

5. A wrench as set forth in claim 4, wherein said toggle mechanism includes a toggle link pivotally coupled at one end to said lever handle and fulcrumed at its other end against an abutment portion of said main handle.

6. A wrench as set forth in claim 5, wherein said abutment portion is positionally adjustable relative to said main handle.

7. A wrench as set forth in claim 6, wherein said toggle link is slotted and coupled to said lever handle by means of a pin slide-fitting within the slotted portion of said link.

8. A wrench as set forth in claim 7, wherein the wrench parts are so shaped, dimensioned and arranged that when said lever handle is moved to close the wrench upon a work-piece the toggle mechanism moves into dead-centered condition and said link moves into a slide-friction-bearing condition relative to said lever handle, thereby stabilizing the wrench in closed condition.

Claims

1. In a wrench of the type having a main handle-like body portion provided with a fixed jaw; a movable jaw pivotally mounted upon said body; a spring normally biasing said movable jaw toward open position relative to said fixed jaw; and a toggle mechanism operable for locking said jaws in closed condition upon a work-piece, said toggle mechanism including a lever handle pivotally connected to said movable jaw and a toggle link having opposite ends thereof operably coupled to said lever handle and pivotally bearing upon a fulcrum device carried by said body; the improvement wherein said toggle link is operably coupled to said lever handle by a pin-slot connection device and said link is provided with a cam surface arranged for engagement with a cam reaction surface portion of said lever handle when the latter is moved in one direction to a wrench-closed position and to simultaneously shift said toggle mechanism so as to arrange the pin of said pin-slot connection device substantially on the center line of said toggle mechanism whereby to frictionally lock said lever handle in said position whereat maximum jaw-locking strain is applicable upon a workpiece by the wrench parts.