US2804793A

US2804793A - Worm-latch means for a slidable side-jaw wrench

Info

Publication number: US2804793A
Application number: US545834A
Authority: US
Inventors: Francis G Coughlin
Original assignee: Individual
Current assignee: Individual
Priority date: 1955-11-09
Filing date: 1955-11-09
Publication date: 1957-09-03
Anticipated expiration: 1974-09-03

Description

p 1957 F. G. COUGHLIN WORM-LATCH MEANS FOR A SLIDABLE SIDE-JAW WRENCH Filed Nov. 9, 1955 IN VEN TOR, franc/Ls 6. 0055/1 i172 Arfo rwgy.

. w 1 3 It United States Patent WORM-LATCH MEANS FOR A SLIDABLE SIDE-JAW WRENCH Francis G. Coughlin, Philadelphia, Pa. Application November 9, 1955, Serial No. 545,834

3 Claims. (Cl. 81-165) The object of the invention is to provide improvements in wrenches, and more particularly in means to positively resist accidental shifting of the usual jaw-adjusting means, and consequently to maintain a predetermined adjustment when once set against the tendency to lose such adjustment, as a result of the usual looseness that characterizes such tools, and the ever-present possibility of consequent alteration from a preset distance between the jaws.

Another object is to provide a wrench that essentially comprises two relatively adjustable jaw elements, and any well known form of worm gear carried by one of said elements in normal mesh with a rack carried by the other element for adjusting the space between the jaws of said elements, said worm gear being characterized by an axial extension that is provided with a roughened surface, and which extension projects laterally beyond the outer surface of the adjacent portions of the wrench, in combination with a lever that is pivotally connected with said wrench at a mid-point, and comprises in one direction a finger-engageable portion, while its opposite end is provided with a roughened surface adapted to normally engage and interlock with the corresponding surface of said gear extension, and a spring to yieldingly maintain such engagement until pressure upon said finger-engageable portion forces said roughened surfaces apart, and which thereby and then only permits said worm gear to be revolved and the distance between said jaw elements increased or decreased.

A further object is to provide a wrench of the general construction as broadly described in the foregoing paragraph, but in which the axial extension of the worm gear axis preferably is generally convexly shaped, as for example in the shape of a bevel gear, and the adjacent surface of the locking lever is provided with a generally concavely shaped surface, said last mentioned surface being provided with complementarily roughened irregularities, such for example as the irregularities of an internal bevel gear, whereby in the absence of manual pressure applied to said lever said surfaces are maintained in interlocking engagement, said worm gear is positively held against rotation, and the distance between the jaws of the wrench is positively maintained.

With the objects thus briefly set forth, the invention comprises further details of construction and operation, which are fully described in the following specification, when read in conjunction with the accompanying drawings, in which Fig. 1 is a .plan view of a wrench comprising one embodiment of the invention; Fig. 2 is an enlarged fragmentary view of the head of the same; and Fig. 3 is a section on the line 33 of Fig. 2.

Referring to the drawings, an adjustable bolt and nut type of wrench is shown as comprising the usual elongated handle 1, of which one end is provided with an angularly enlarged head 2, having a freely projecting, right-angle extension 3 at one end, provided'with a clamping surface 4 and an inwardly positioned surface 5, which serves 2,804,793 Patented Sept. 3, 1957 as an inner limit for movement of a bolt or nut against which said jaw surface is placed. Extending diagonally through said head and parallel with said inner surface 5 is a bore 6, in which is reciprocatively positioned the base portion 7 of a freely projecting movable jaw 8 having a clamping surface 9, between which and said firstmentioned surface 4 a bolt or nut may be clamped.

The enlarged head 2 is provided with a windowlike aperture 10 into which said bore opens through two of its opposite and one intervening surfaces. Within said aperture is rotatably positioned a worm 11, that is provided upon its innermost end with an axially directed trunnion 12, revolvably positioned in a bore 13 in one side wall of said aperture, while in the opposite direction said worm is provided with an axially projecting trunnion 14, that extends through a bore 15 in that end wall of said aperture adjacent to the movable jaw 8. Rotation of said worm by manual engagement with its characteristic spiral ridge operates to vary the distance between said jaw surfaces in the usual manner.

The outermost end of the worm trunnion 14 is provided with a radially enlarged terminal 16 having a suitably serrated or otherwise roughened convex outer surface, the irregularities of which may take the form of radially extending, circumferentially spaced ridges and grooves, such as are suggested by a bevel-gear. Complementary to this surface is the concave surface 17 of the transversely enlarged head 18 of one end of a lever, which medially comprises a pair of transversely spaced angularly directed cars 19, that are positioned upon the opposite sides of said handle shank adjacent to the windowlike aperture 10, and beyond while said lever comprises a finger engageable end portion 20. Said end portion is normally maintained spaced from said handle under the influence of a coil spring 21 whose opposite end extends into and is secured within a bore 22 in said handle.

Having thus described my invention, what I claim and desire to protect by Letters Patent of the United States is:

l, A wrench, comprising a fixed element having a work surface, a clamping element having a work surface substantially parallel with said first work surface and a shank movable longitudinally in a path angularly disposed with respect to said work surface, said shank being provided with rack teeth, a worm longitudinally fixed but rotatably carried by said fixed element and engaging said rack teeth, one end of said worm being provided with bevel gear teeth, and a member movably carried by said fixed element and having a surface provided with concavely recessed bevel gear teeth normally in locking engagement with the teeth of said worm end, to positively prevent accidental rotation of said worm and variation in the distance between said work surfaces as the interengageable teeth wear.

2. A wrench, comprising a fixed element having a manually engageable portion and a work surface, a clamping element having a work surface substantially parallel with said first work surface and a shank movable longitudinally in a path angularly disposed with respect to said work surface, said shank being provided with rack teeth, a worm longitudinally fixed but rotatably carried by said fixed element and engaging said rack teeth, one end of said worm being provided with a convex surface having bevel gear teeth, and a lever pivotal-1y carried by said fixed element and having a concave surface provided with bevel gear teeth that are complementary to and normally in locking engagement with said first gear teeth, to positively prevent accidental rotation of said worm and variation in the distance between said work surfaces as said gear teeth Wear, and resilient means to normally maintain said lever in operative position.

3. A wrench, comprising a fixed element pierced by a windowlike aperture and having a work surface, said element being also provided with a transversely extending channel opening in opposite directions into said aperture, a clamping element having a base portion reciprocatable in said channel and a work surface substantially parallel with said first Work surface, said base portion being provided with rack teeth, a Worm longitudinally fixed within said aperture and having a spiral rib in engagement with said rack teeth, said Worm in one direction having an axial extension that projects laterally from one side of said fixed element and is provided with a surface having regularly arranged bevel gear teeth, a lever pivotally carried by said fixed element and atone end having a surface provided with concavely recessed bevel gear teeth normally engageable with said first gear teeth, to

4 positively prevent accidental rotation of said worm and variation in the distance between said Work surfaces, and resilient means to normally maintain said lever in operative position, the opposite end of said lever being manually actuatable to shift said lever against said resilient means to separate said toothed surfaces.

References Cited in the file of this patent UNITED STATES PATENTS Ryland Oct. 2,