US3078491A

US3078491A - Broadknife

Info

Publication number: US3078491A
Application number: US64572A
Authority: US
Inventors: Robert G Ames
Original assignee: Ames Taping Tool Systems Manufacturing Co
Current assignee: Ames Taping Tool Systems Manufacturing Co
Priority date: 1960-10-24
Filing date: 1960-10-24
Publication date: 1963-02-26
Anticipated expiration: 1980-02-26

Description

Feb. 26, 1963 R. G. AMES BROADKNIFE Filed Oct. 24. 1960 INVENTOR.

ROBERT (3. AMES AT TORNEYS lllllll 3,978,49l Fatented Feb. 25, 1953 3,073,491 BROADKNIFE Robert G. Ames, Hilisborough, Calif., assignor, by mesne ass gnments, to Arms Taping Tool Systems Manufactuning Co., Harvey, lill., a chrporation of Delaware Filed Oct. 24, 1960, Ser. No. 64,572 1 Claim. (Cl. 15236) The present invention relates to improvements in a broadknife. It consists of the combinations, constructions, and arrangement of parts, as hereinafter described and claimed.

An object of my invention is to provide a broadknife having a resilient trowelling blade which is connected to an operating handle, the blade being reinforced by resilient shims positioned to reduce the bending pressure on the area where the handle is connected to the blade, when the blade is flexed, and to distribute the bending pressure over a wider area. This arrangement will prevent breakage of the blade as the latter is flexed.

Other objects and advantages will appear as the specification proceeds. The novel features will be set forth in the appended claim.

Drawing For a better understanding of the invention, reference should be had to the accompanying drawing, forming part of this specification, in which:

k l flGURE 1 is a fragmentary plan view of my broad- 'm e;

FIGURE 2 is a side elevational view thereof; and

FIGURE 3 is a plan view of one of the resilient shims.

While I have shown only the preferred form of my invention, it should be understood that various changes, or modifications, may be made within the scope of the annexed claim without departing from the spirit thereof.

Detailed Description In carrying my invention into practice, I provide a handle indicated generally at A, which is fashioned with a bifurcated end B defining a pair of spaced lugs arranged in confronting relation with one another. The handle A may be made of any suitable length and is preferably made of tubular material having a bore 11 extending longitudinally thereof. The bifurcation in the bandie defines saddles 12 on opposite lateral sides of the handle.

Moreover, I provide a resilient trowelling blade C having opposite faces 13, a leading end 14 and a trailing end 15, the latter providing a trowelling edge when the broadknife is being used. The spaced lugs 10 are disposed to straddle the leading end 14 of the blade C, when the broadknife is assembled. It will be apparent that the blade C defines a trowelling portion C extending rearwardly beyond the lugs 10.

As clearly shown in the drawing, a pair of resilient reinforcing shims D project into the space between the lugs 1%, with each shim being interposed between one of the lugs 10 and the adjacent face 13 of the blade. Bolts 16 are inserted through holes 17 formed in the lugs 1t), and these bolts extend through holes 18 in the shims D and holes 19 in the blade C. These bolts are provided with nuts 29 for drawing the lugs 10 into clamping relation with the interposed blade C and shims D, thereby removably connecting the blade C to the handle A.

Referring to FIGURE 1, it will be observed that the shims D project longitudinally beyond the lugs 10 toward the trailing end of the blade C; and, also, project laterally in both directions beyond the lugs. The shims D bear against the opposite faces 13 of the blade C to thereby reduce the bending pressure on the area where M the lugs it are connected to the blade, when the blade is flexed, and the shims distribute the bending pressure over a wider area for preventing breakage of the blade.

Particular attention is called to the fact that the blade C is fashioned with opposite lateral side edges 21 that converge toward the leading end 14 thereof. These edges 21 project into the bore 11 of the handle A and are seated in the saddles 12, thereby aiding in supporting the blade against lateral displacement from between the lugs 19. Moreover, each shim D is fashioned with opposite lateral side edge portions 22 that project into the bore 11 of the handle A and are seated in the saddles 12, thus aiding in supporting the shims against lateral displacement from between'the lugs 10.

Prior to using the resilient shims D, actual tests disclosed that the blade C would not last very long due to breakage of the blade in the area where the handle A is connected to the blade. However, when the shims are utilized, the breakage of the blade is at a minimum.

It will be noted that each shim D is formed with opposite lateral side edges 23 that converge rearwardly relative to one another in a direction extending toward the trailing end 15 of the blade C. When the shims D are not provided, the normal tendency of the blade is to flex about a stress line 24, as the trailing end 15 is pressed against a wall or the like. It will be apparent from FIGURE 1 that the rearwardly converging side edges 23 of the shims D are spaced inwardly from the forwardly converging lateral side edges 21 of the blade C, and this arrangement will allow the flexing stress imparted to the blade during use to spread into the areas 25 of the blade, which areas are disposed on opposite lateral sides of the shims. This will materially reduce the tendency of the blade to break during flexing thereof. Moreover, the rearwardly converging side edges 23 extend diagonally relative to the normal stress line 24, and this is an important structural feature contributing to a longer life of the blade.

I claim:

A handle to tool connection comprising a handle having a bore extending longitudinally thereof, said handle terminating in a bifurcated end embodying a pair of flat spaced lugs arranged in confronting relation with one another and projecting beyond the bore end of the handle, the points of merger of the sides of said lugs with the bore end of the handle providing a pair of saddles; a resilient trowelling blade having opposite faces, leading and trailing ends with the leading end shorter in length than the trailing end and being disposed between the lugs and having a non-circular periphery received in the saddles; the blade defining a trowelling portion extending rearwardly beyond the lugs and of greater width than the width of the lugs; a pair of resilient reinforcing shims projecting into the spaces between the lugs and the adjacent face portions of the blade and having non-circular leading edges received in the saddles; the shims having trailing edges slightly less in length than the widths of the ends of the lugs and being spaced from the ends of the lugs; said shims also having opposite diverging sides extending from the ends of the shim trailing edges toward the sides of the blade so as to provide lateral shim portions that extend beyond the sides of the lugs; and connecting means securing the blade and shims to the lugs.

References Cited in the file of this patent UNITED STATES PATENTS 316.924 Visscher Apr. 28, 1885 FOREIGN PATENTS 1,017,961 Germany Oct. 17, 1957