Hack saw frame

1,995,679

March 26, 1935.

F. H. KELLEY

HACK SAW FRAME

Filed May 29, 1934

<img file="US1995679A_D0001.tif" />

Patented Mar. 26, 1935

1,995,679

UNITED STATES PATENT OFFICE

1,995,679 HACK SAW FRAME

Frederick H. Kelley, Franklin, N. H., assignor to G. W. Griffin Co., Franklin, N. H., a corporation of New Hampshire

Application May 29, 1934, Serial No. 728,093

Claim. (Cl. 145—108)

This invention relates to hack saw frames and and has for its object to provide a novel hack saw frame which is inexpensive to manufacture, Which is constructed so that the saw blade can 5 be quickly and easily installed in the frame or removed therefrom and which is further so constructed as to hold the saw blade under the proper amount of tension.

In order to give an understanding of the in10 vention I have illustrated in the drawing a selected embodiment thereof which will now be described after which the novel features will be pointed out in the appended claim.

Fig. 1 is a side view of a hack saw frame em15 bodying the invention;

Fig. 2 is a fragmentary view showing a portion of the blade-carrying arm and the blade-locking member;

Fig. 3 is a section on the line 3—3, Fig. 1 with ²⁸ parts broken out;

Fig. 4 is a section on the line 4—4, Fig. 1;

Fig. 5 is a section on the line 5—5, Fig. 1.

My improved hack saw frame, which is indicated generally at 1, is made from a length or ²⁸ strip of material which is bent to form the back portion 2 of the frame, a blade-carrying arm 3 extending laterally from one end of the back portion, and a handle portion 4 extending laterally from the other end of the back portion. ³⁰ The handle portion 4 is considerably longer than the blade-carrying arm 3 and the end of said handle portion is bent into a U shape as indicated at 5 so that the arm 6 of the U is ₃₅ directed backwardly toward the back 2.

The extremity of the arm 6 is provided with a pin or projection 7 adapted to enter the usual aperture in one end of the saw blade 8. The other end of the saw blade 8 is attached to the 40 end of the blade-carrying arm 3 in such a way that when the blade is installed in the frame the frame will be flexed slightly and the arm 3 and handle portion 4 will be drawn together slightly from their normal position. The frame ⁴⁸ 2 has some resiliency and because of the flexed condition of the frame the resiliency thereof serves to hold the blade 8 taut and under the proper degree of tension.

₅₀ The handle portion 4 is provided with a handle grip 9 of wood or other suitable material which encloses the portion 4 of the frame and provides a convenient hand hold to grasp in the hand. This handle grip may be made of wood 55 or any other material and is shown as having a groove 10 in which the portion 4 of the frame is received. This portion 4 may be retained in the groove in any suitable way and as one simple and inexpensive but effective way I have illustrated a plurality of staples 11 which are driven 5 into the handle in such a position that the legs of the staples will cross the groove 10 in front of the portion 4. Any other way of locking the handle portion 4 in the handle grip might be employed, however, without departing from the 10 invention.

The end of the saw blade 8 is detachably secured to the end of the blade-carrying arm 3 by a simple means which is constructed so that the attachment and removal of the blade can be very 15 easily and quickly accomplished.

Pivoted at 12 to the end of the blade-carrying arm 3 is a lever arm 13 which is provided with a laterally-extending pin 14 to which the saw blade 8 is secured, said pin being of a size to be ²⁰inserted through the usual aperture with which the hack saw blades are provided.

The lever arm 13 is adapted to be swung from its operative position in which it is folded against the arm 3 to its open position shown in dotted ²⁵lines Fig. 1. When the saw blade is to be installed in the frame the member 13 will be swung into its open position and one end of the saw blade 8 will be attached to the arm 6 of the handle _goportion by inserting the pin 7 through the aperture in the end of the saw blade and the other end of the saw blade will be attached to the swinging member 13 by inserting the pin 14 through the aperture in said other end. The lever 35 arm 13 is then swung from its open dotted line position into its closed operative position shown in full lines.

The arm 13 is preferably U shape in cross section and when it is in operative position the 40 U shape of said lever arm embraces the arm 3.

The pin 14 extends across the channel of the lever arm 13 and the lower end of the frame arm 3 is cut away as shown at 15 to accommodate said pin 14 when the lever arm 13 is in its opera- ⁴⁵tive position. During the swinging movement of the member 13 from its open to its closed position the pin 14 swings about the pivot 12 as a center and because the saw blade 8 is attached ₅₀to the two pins 7 and 14 the movement of the pin 14 in its arcuate path will cause the arm 3 and the handle portion to be drawn together slightly thereby flexing the saw frame. The yielding or flexing movement of the saw frame may take 55

1,995,679 place in either the arm 3 or in the handle portion 4 or in both parts of the saw frame.

The swinging movement of the arm 13 from its open to its closed position carries the pin 14 g from one side to the other of the center line of the pivot 12 and the pm 7. As soon as the pin 14 passes this center line then the resiliency of the frame tends to complete the swinging movement of the member 13 and to fold it against the arm 3. IQ The relation between the length of the saw blade 8 and the normal distance between the arms 3 and 6 is such that when the saw blade is installed in the frame and the lever arm 13 is in its operative position the frame will still be 15 slightly flexed thereby applying a tension on the saw blade which will hold it taut. This tension locks the lever arm 13 in its operative position so that said arm will not be accidentally swung into its open position when the saw is be20 ing used.

The installing of the blade in the arm, therefore, involves simply swinging the lever arm 13 into its open position, applying the saw blade to the pins 7 and 14 and then swinging the lever 25 arm 13 back into its operative position.

The handle portion 4 is longer than the bladesupporting arm 3 so that if the line occupied by the saw blade were extended it would cut the handle grip at its intermediate portion. This is an advantage because the power or force employed in manually operating the saw is applied to the handle grip substantially in the line of the 5 saw blade. This makes a frame in which the power is most effectively applied.