US2018437A - Bow saw - Google Patents

Description

@ctZZ, 1935. BURKHARDT 2,018,437

BOW SAW V Filed May 31, 1954 Patented Oct. 22, 1935 UNITED STATES PATENT OFFICE BOW SAW Hermann Burkhardt, Weiningen, Switzerland Application May 31, 1934, Serial No. 728,391 In Switzerland June 10, 1933 1 Claim.

which can be handled easier in places difiicult of access and which easily can be taken apart and put together. To attain these objects the new saw consists of two straight wooden uprights of the same shape, a metal bow with ends bent down at an angle loosely abutting against and engaging into recesses of the uprights in the manner of knuckle-joints, tension-rods actuated by wingscrews attached at one end to the angular points of the metal bow by means of articulated joints and lying at the other end in the prolongation of the mean part of the bow in s1its of the uprights open on top, a blade carried parallel to the mean part of the bow, said bow, tension rods and blade forming the only transversal parts between the uprights.

The accompanying drawing exemplifies an adaption of the invention and shows:

Fig. 1a lateral view of the saw, partly in section;

Fig. 2the detached bow;

Fig. 3-the blade with the uprights in another position; and

Fig. 4-a section along line I-I of Fig. 2.

Blade l at its ends is provided with adjusting pins 2 connected by means of articulated joints, said pins passing through bores of the uprights 3, the latter consisting of straight wooden pieces and the blade possessing handles 4 bearing on the uprights. 5 is a metal bow, having in the design shown an intermediate straight part 6 with ends I bent down at a sharp angle. Ends 8 of said ends 1 rest loosely, with some play, in recesses 9 of the uprights 3. Tension-rods I l, carrying wing-screws [3, pass through slits 12 open on top, of uprights 3, said tension-rods acting on straight part 6 ofbow 5 5 by means of forks l9 jointed loosely to said how. When tightening or slackening the blade, by turning the wing-screws i3, ends 8 form fulcrums for the uprights 3 on bow 5.

My saw has the following advantages: there 10 are but two horizontal transverse parts, that is blade I and the mean part of bow 5 parallel to it, so that between the two there is provided much room to work in; since the ends of bow 5 are bent down at an angle, wing-screws II are 15 aligned with the mean part of bow 5 (see Fig. 1) giving rise to favorable tensile stresses; since ends 8 rest loosely in uprights 3, and the wingscrews II sit in s1its i2 open on top, the saw can easily be taken apart and put together. The 20 straight wooden pieces of the uprights 3 can easily and cheaply be made.

I claim:

A buck hand saw having two straight wooden uprights of the same shape, a metal bow with 25 ends bent down at an angle loosely engaging in recesses of said uprights, tension-rods with wingscrews at one end attached to the angle-points of the bow by means of a joint and at the other end lying in alignment with the mean part of the bow in s1its of the uprights open on top, a blade parallel to the mean part of the bow, said blade, bow and rods forming the only transversal parts between the uprights.

HERMANN BURKHARDT.

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