US 2800823 A
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v My B? R957 H. TUGEND PLIER-TYPE vWRENCH Filed Nov. l, 1954 -v Hewwidn" Tugend by: SMN@ This invention relates to a lever wrench serving as a gripping, holding and clamping tool, of the kind comprising a pair of clamp jaws pivotally connected together, and said jaws being movable with respect to the other by a handle lever articulated on the body of the movable clampjaw, a toggle lever support pivotally connected at one end to the uppershorter lever arm of said handle lever so as to form with said arm a pair of toggle levers, the other end of said toggle lever support being pivotally mounted in a support in another handle lever rigid with the stationary jaw body, said support being longitudinally slidable in said second-mentioned handle lever by means of an adjusting screw and nut, and a release lever pivotally mounted in the first-mentioned handle lever for initiating the release of the toggle lever pair when .in the clamped position. Y A
In order that this kind lof lever wrench clamping device-may be elective for diterent jaw distances or jaw widths and4 to permit the adjustment of the clamp jaws to a determined jaw width, one lever armi of theopenable and closable toggle lever pair is made adjustable in length with the aid of the adjusting nut. In known constructions the adjusting nut and also the handle of the vrelease lever lie outside the reach of the-hand effecting the clamping and adjustment, so that the 4operation of the known tool is troublesome and time-consuming.
Moreover, in known tools of this type the adjusting screw and adjusting nut also lie exposed between the movable and stationary clamp bodies, or outside the latter, so that the thread of the adjusting screw can easily be damaged.
The present invention aims at obviating the foregoing disadvantages and to this end consists in a lever wrench of the foregoing kind the end of the toggle lever support, bearing against the lixed jaw handle lever, is mounted in a ball socket which is connected to an adjusting screw housed between the limbs of a U-shaped handle lever of the fixed jaw body, the adjusting nut of said adjusting screw being adapted to be operated from the outside of said handle lever and is immovably mounted between the edges of a cut-out in said U-shaped handle.
According to a further feature of the invention, the release lever is constructed as a cranked, single-armed rolling lever disposed between the U-shaped cheeks of the movable handle lever inthe plane of the toggle lever pair, the fulcrum of said rolling lever being the apex curve lying in the clamped position against the toggle support lever beneath the common pivot bolt of the toggle pair and the free bent over lever end of said rolling lever extends through an elongated slot in the handle lever at the level of the thumb of the users hand, while the other end is pivoted on said handle leverand is bent away towards the end of the handle.
In order that the invention may be more readily understood, reference is made to the accompanying drawings which illustrate diagrammatically and by way of eX- ample, one embodiment of lever wrench in accordance therewith, and in which:
tes atent l 2,800,823 Patented July 30, 1957 Figure 1 is a side elevation partly in section showing the toggle lever arrangement and the release lever in the clamped position with the smallest jaw width;
Figure 2 is a section taken on the line A-B of Figure 1; and
Figure `3 is ya view similar to Figure 1l showing the wrench adjusted to the largest jaw width, the full lines showing the clamped position and the chain-dotted lines the release position.
Referring to the drawings, the lever wrench comprises a stationary jaw body a, on which there is articulated at z in a manner known per se a movable jaw body b, the handle lever c of whichis pivotally connected by a pivot bolt d to the movable jaw body b. The handle lever c of the movable jawn body b is connected in manner knownper se to the handle lever e of the fixed jaw body a by means of a pivot bolt w and a toggle lever f of adjustable length, so that the toggle lever f forms with the lever arm g of the handle -leg c an openable and clos able toggle lever-pair, by means of which the jaws can be secured at a determined jaw width or in the clamping position, depending on the adjusted length of the toggle lever f, and released again by means of a release lever u.
According tothe present invention the other end of the toggle lever f is mounted by a ball and socket connection in `a support block l, which is connected to an adjusting screwy mfhoused between the web and cheeks of the handle lever e which is U-shaped in crosssection, an externally operable adjusting nut n of which is mounted between theA edges 0"of a cut-out p in the handle of width corresponding tothe length of the adjusting nut' n.' The depth ofrthepcut out is measured firstly in accordance with the` diameter of the adjusting nut n, and secondly in accordance with the externaldiameter of the adjusting screw m which, when screwed together with the adjusting nut n, is mounted on or detachably connected to the handle lever e together with said adjusting nut between the support of the adjusting nut n on the one hand and an abutment and support q of the embedded adjusting screw m on the other hand.
One or both side cheeks of the handle e is or are provided with a window-like aperture r and with indicating marks for the ready observation of the position of the jaw width or of the respective clamping position of the jaws.
The handle cheek has scale lines and markings 0, 1 and 2 for the smallest, middle and greatest clamping width of the jaws, while the support block l carries a datum mark which in the position of the smallest clamping width as shown in Figure 1 coincides at the top with the scale mark 0 and in the position of the greatest clamping width as shown in Figure 3 coincides with the scale mark 2 at the bottom.
A helical spring s, which is connected at one end to the movable jaw body b between the pivot bolt d and the bearing bolt t and at the other end between the cheeks of the handle e of the fixed jaw body a, holds the toggle lever f securely with its ball end in the open and correspondingly shaped socket bearing of the support block l. This is of course only necessary in the release position shown in chain-dotted lines in Figure 3.
The release lever u is arranged in the plane of the toggle lever pair between the cheeks of the movable handle lever c. The release lever u is constructed as a single-armed bent rolling lever, the downwardly directed lever arm of which is pivoted between the cheeks of the movable handle leg c, while the other lever arm projects through an elongated slot of the movable handle c and is provided at the end with a thumb plate. The fulcrum of the release lever is formed at any given moment by a point of the approximately quadrantal to semicircular apex line, which at any given moment in the clamped position of the extended toggle lever pair touches the toggle lever f, below the common pivot bolt w. In this clamped position of the release lever .11, which also corresponds to the clamped position .at the moment in question of the clamp jaws, it lies with the back facinggaway from the apex line on'the slot edges on the lower side. In order to take into account the different `position of the movable jaw body b and the different inclination of the toggle lever fin different clamping positions of the jaws, a flat spring v, acting as 'an equalizing spring, is preferably disposed between the back of the release lever u and the rear wall of the slot in the handle.
By the foregoing arrangement it will be seen that the adjusting nut n is situated near the reach of the index linger and the thumb plate of the release lever u is situated at the level of the thumb of the hand holding or operating the clamping device.
If a workpiece of the size 0 is to be clamped, the thickness of which corresponds to the minimum clamping width, while the left hand holds the workpiece, lthe index nger of the hand holding the wrench is used to move the adjusting nut until the datum line of the support block l coincides with the zero line of the scale. Through further adjustment by feel of the adjusting nut n by means of the index finger to the correct clamp position of the toggle lever arrangement, which still permits tight clamping `of the workpiece, the nal position of the jaws for clamping the workpiece of the size 0 is reached. By compressing the hand, the wrench jaws are now brought into the clamp position of the extended toggle lever arrangement. In this position the release lever u touches the toggle lever f below the common fulcrurn point w of the toggle lever pair. The release lever'ru is now in the clamp position. The release is now com pleted by pressure of the thumb ofthe hand in contact on the thumb plate of the release lever u.
The position shown in chain-dotted lines of the movable clamp jaw body b and of the rockable handle c in Figure 3 corresponds to the release position of the clamping wrench with the maximum clamping width, which is indicated on the scale by II. In this case the helical spring s prevents further movement apart of the wrench jaws.
1. In a wrench type pliers having a pair of relatively movable handles and an over-center locking element operatively connected to said handles, the improvement corn- Yprising a single-armed substantially zigzag-shaped releasing lever pivotally mounted at one end thereof on one of said handles in such a manner that the free end portion of said lever extends in the direction of said one handle, said lever being so constructed and arranged as to impart a releasing movement to said locking element upon movement of said free end portion toward said one handle.
2. The arrangement defined in claim 1 wherein said one handleis channel-shaped and opens inwardly and wherein the intermediate portion of said lever extends through a longitudinal slot of said one handle which slot is only of substantially such length as to permit the pivotal movement of said lever which is necessary in order that said lever may effect releasing movement of said locking element.
References Cited in the le of this patent UNITED STATES PATENTS