US2725086A - Detachable grip for increasing leverage of tool handles - Google Patents

Description

DETACHABLE GRIP FOR INCREASING LEVERAGE OF TOOL HANDLES Filed Jan. 9, 1952 I In;

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United States Patent f) DETACHABLE GRIP FQR INCREASING LEVEHAGEDF TUOIIHKNDLES Edward N. Keyes, Short Hills, N. J.

Application January 9, 1952, Serial No. 265,696

1 Claim. (Cl. 145-61) This invention relates to an auxiliary tool handle that is detachably applied over the ordinary permanent handle of a screw driver, or other rotary tool, to increase the torque that can be exerted with the tool.

Various types of auxiliary tool handles have been proposed and it is an object of this invention to provide an improved auxiliary handle which combines substantial increase in leverage with convenience in application and removal, and with simplicity and very low manufacturing cost.

In the preferred construction, the auxiliary handle of this invention is an integral unit without any moving parts and with a hub portion that has a recess for receiving the tool handle. The recess has straight sides and a transverse cross-section that corresponds to that of the tool handle.

The tool handle may fit tightly with a slight wedging action when fully inserted into the recess of the auxiliary handle, but it does not fit tightly enough to prevent it from being pulled out of the recess by hand when the auxiliary handle is to be removed from the tool.

With this invention a set of hand tools can have the usual small diameter handles, and the resulting convenience in storing in a tool chest; and any one of them can be used to apply greater torque, than would otherwise be possible, by applying the auxiliary handle of this invention over the permanent handle of the particular tool selected for use.

Other objects, features and advantages of the invention will appear or be pointed out as the description proceeds.

In the drawing, forming a part hereof, in which like reference characters indicate corresponding parts in all the views,

Figure 1 is a side elevation of a screw driver equipped with an auxiliary handle made in accordance with this invention; and

Figure 2 is a sectional view taken on line 2-2 of Figure 1.

Figure 1 shows a screw driver having a working element with its lower end shaped to fit into a screw slot, and a shank 11 at its upper end extending into ahandle 12. The shank 11 is commonly made with a square cross section in order to prevent it from turning in thehandle 12. The socket in the handle, which holds the shank, has a cross section corresponding to that of the shank and fits tightly so that the shank and handle are permanently connected to one another. Screw drivers commonly have aferrule 14 at the lower end of the handle to prevent any spreading of the handle, when the handle is made of wood, and for ornamental purposes with handles that do not need to be reinforced against spreading.

The screw driver shown in the drawing is merely representative of rotary hand tools, and it will be understood that thehandle 12 may be the permanent handle of any hand tool which is operated by rotating about an axis which extends lengthwise of the handle. The material, of which thehandle 12 is made, may be wood, metal, plastics, or any other substance suitable for the purpose.

The handles of tools which must be rotated about their 2,725,086 we 2a 1 Wheel extendsv from one, side of. the wheel. 17; and preferably from the lower side only so as to leave the upper side of the wheel unobstructed. This makes it possible to obtain a firmer grip on thewheel 17 when turning it with one hand.

Thehub 18 has anannular face 22 at the end of the hub remote from the wheel, as best shown in Figure 1. There is arecess 24 opening through theend face 22, and this recess preferably extends throughout most of the longitudinal length of therecess 24 to anupper end wall 25 at the top of therecess 24.

Therecess 24 has a transverse cross section with flutes which extend into the grooves between theflutes 15 of the handle. In order to have the auxiliary handle fit tools of different sizes, there is ashoulder 23 intermediate the upper and lower ends of therecess 24, and the cross section of the recess above theshoulder 23 is smaller than below the shoulder. The recess 24 below theshoulder 23, is of the same transverse cross section as thehandle 12, and the upper end of the handle abuts against the annular surface provided by the shoulder. The upper portion of the recess, above the shoulder, fits a handle of smaller size. Other embodiments of the invention can have different cross sections, of non-circular contour, that engage thefluted handle 12 without fitting into all of the contours of the handle.

It is a feature of the invention, however, that therecess 24 is of non-circular, transverse cross section; and that the auxiliary handle is held against rotation, with respect to the tool, by having thenon-circular recess 24 fit noncircular portions of thehandle 12 so as to force thepermanent handle 12 to rotate with theauxiliary handle 17.

The sides of therecess 24 are preferably straight, at least throughout the greater portion of their length; and in any event, the sides of therecess 24 extend in directions substantially the same as the sides of the tool handle with which the auxiliary handle is to be used.

Toward the upper end ofrecess 24 the side walls of the recess are preferably made so that they converge slightly and grip the upper end of thehandle 12 with enough wedge action to hold thehandle 12 in therecess 24. As previously explained, this wedging action is light and the auxiliary handle can always be pulled off by hand.

The preferred embodiment of the invention has been illustrated and described, but changes and modifications can be made without departing from the invention as described in the appended claim.

What is claimed is:

A hand grip element for use with a tool which has a working element with a shank extending into and rigidly connected with a tool handle which has a section of substantially uniform diameter with flutes in its outside surface for facilitating the gripping of the handle, said grip element including a wheel having a top face with a broad convex surface for comfortable contact against the palm of the hand of a person using the grip element to exert both the axial and torque forces required for operation to be performed by the tool, the wheel having a rounded perpiheral portion and a bottom face with which the peripheral portion merges and under which the fingers of the hand extend when the wheel is firmly gripped with its top face against the palm of the hand, and a hub for the one-p iececop s truct ion with thewheel, but

wheel rigidly connected with the remainder of the wheel and extending downwardly for a substantial distance below said bottomface at a substantial distance inward from the peripheral portion of the wheel, said hub havinga lower end face with a recess opening therein and extending up- 5 ward to a location above the bottom face of the wheel and the recess having side walls parallel to one another and fluted for at least the lower portion of their length and said recess having a cross section that fits the cross section of the handle of the tool with which the element is intended to 10 be used.

References Cited in the file of this patent UNITED STATES PATENTS 445,451 Miller Jan.27, 1891 15 4 Chesson June 27, 1899 Jacobs May 18, 1909 Probst Mar. 7, 1911 Barnes June 21, 1921 Booth Sept. 20, 1921 Peterson Oct. 5, 1926 Schneider Dec. 31, 1929 Fratz Dec. 2, 1952 FOREIGN PATENTS France Sept. 14, 1926

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