US2731993A - mount - Google Patents

Description

Jan. 24, 1956 G. w. MOUNT MAGNETIC HAMMERS Filed Jan. 4, 1952 INVENTOR GEORGE VV. MOUNT BY @07M ATTORNEYS United States Patent O MAGNETIC HAMMERS George W. Mount, Greenfield, Mass. Application January 4, 1952, Serial No. 265,034 3 Claims. (Cl. 145-30) This invention relates to an improvement in magnetic hammers and the method of making them. The advantage of magnetic hammersA is that nails and tacks are initially held against the peen or driving face to facilitate the driving of the nail or tack. Many magnetic hammer constructions have been proposed all of which, as far as is known, involve the magnetizing of the metal of which the hammer head is made.

One objectionable feature of these previously proposed constructions is that the magnetic life of such hammers is relatively short. Furthermore both ends of the head are magnetic.

It is the principal object of the present invention to provide a magnetic hammer construction by which the magnetism of the hammer is made permanent and, if desired, only one end of the head may be rendered effectively magnetic.

Other and further objects and advantages residing in the details of construction will be made apparent in the following specification and claims and in the drawings.

In the accompanying drawings,

Fig. 1 is a side elevational view of a hammer disclosing one embodiment of the invention, parts being broken away;

Fig. 2 is a fragmentary view similar to Fig. 1 but showing an intermediate step in the construction of the hammer;

Fig. 3 is a plan view of the structure of Fig. 2;

Fig. 4 is a fragmentary view similar to that of Fig. 1 but showing an alternative construction;

Fig. 5 is a similar view showing another alternative construction;

Fig. 6 is a plan view of the structure of Fig. 5 showing the structure prior to the introduction of the magnet;

Fig. 7 is a fragmentary detail view showing still another alternative construction; and

Fig. 8 is a detail view showing respective modifications in the shape of the permanent magnet and the manner of securing the closure, which forms the striking face, in place.

Referring to Figs. 1, 2 and 3, the hammer head is generally indicated at 1. The head 1 is formed in any suitable manner from non-magnetic material such as brass, or any suitable non-magnetic metal or alloy or a synthetic plastic material.

One, or both, of the end portions of the head are formed with a bore 2 extending from the free end of the head to a point short of the handle receiving opening 3 of the head. A small vent opening 4 and a larger opening 5 extend from the outer face of the head into the bore 2. A cylindrical permanent magnet 6, of less length than bore 2 is slid into the bore as shown in Fig. 2. The material of which permanent magnets are made and the method of permanently magnetizing them are well known, are not per se a part of the present invention and need not be specifically described here. It is suicient to point out that such permanent magnetizable material is too expensive and brittle for use as hammer head material.

For greatest magnetic eciency the length of magnet 6 should be approximately ve times its diameter. The length of bore 2 is substantially in excess of the length of the magnet 6 to be used. As shown in Fig. 2 the magnet is initially positioned at the base of the bore 2, in which position it is temporarily held, by a wedge or other means, not shown, inserted through opening 5. While the magnet 6 is thus held at the base of the bore 2, a relatively thin disc or cap 7 is welded, brazed, soldered or otherwise secured, as indicated at 8, to the free end of the head to close the bore 2 and form the peen or driving face of the hammer. The disc or cap 7 may be the same or a different material from that of the head.

The length of the bore is made such that while closure 7 is being welded or brazed in place, the magnet 6 is held suiiiciently spaced from the closure so that the temperature of the magnet is not raised to or above the critical temperature, approximately 350 F., at which its magnetic properties are damaged.

The magnet 6 is then released and slid forwardly into contact with closure 7 as shown in Fig. l. A non-magnetic filling material 9 such as cold solder, or a thermoplastic or thermosetting resin or other suitable material having a melting temperature below the critical temperature of the magnet, is introduced through opening 5, opening 4 permitting the air to escape as the filling material lls the cavity behind the magnet. Upon setting of the lling material 9 the magnet is permanently held in place. The outer surface of the head, including the exposed surface of the iillng material at the openings 4 and 5, is then polished or otherwise finished in any desired manner.

In the alternative structure of Fig. 4 a bore 10 is formed in the head extending from an outer side surface of the head to a point just short of the peen surface 11. The permanent magnet 12 is slid into the bore 10 and against the thin wall of the peen end of the head. The open end of the bore 10 is lled with non-magnetic filling material 13 of the character previously mentioned, after which the head is given a finished surface.

In the alternative structure shown in Figs. 5 and 6 a groove 15 is formed in the head 1 with the outer end of the groove closely adjacent the peen surface 16. The length of groove 15 is substantially equal to that of permanent magnet 17 which is seated in the bottom of the groove. With the magnet in position the groove is iilled with non-magnetic material 18 of the character previously described and the head polished or otherwise given a surface finish.

In Fig. 7 a construction is shown in which the head 1 is provided with a cylindrical recess 20 opening from the peen end of the head. The peen end is reduced in diameter and provided with exterior threads 21. A permanent magnet 22 is seated in the recess 20, the length of the magnet being substantially that of the recess. An interiorly threaded cap 23 is threaded on the reduced portion 21 to retain the magnet in place and provide the peen surface of the hammer.

Fig. 8 shows a modified shape of magnet as well as a modified form of end closure adaptable, for example, to the structure of Figs. 1, 2 and 3. As shown in Fig. 8 the end of the permanent magnet 25 is made frustoconical, tending to concentrate the lines of magnetic force. The end portion of the head is reduced in diameter and shaped to the end of the magnet as indicated at 26 and the cap member 27 is welded, brazed, soldered or otherwise secured in place to enclose the magnet and provide the peen or striking surface of the hammer.

By providing a small but strong and permanent magnet enclosed in the head of the hammer which is formed of non-magnetic material the magnetic life of the hammer is substantially increased, the greatly increased life and magnetic elciency more than making up for any greater material or manufacturing cost over prior constructions. In all of the constructions, as is obvious, one end of the magnet is separated from the striking surface of the hammer head by only a thin wall, of the order of one-eighth of an inch for example, thereby locating a strong permanent magnetic eld at the striking face.

As previously stated the cap member which may be used in any or all of the forms shown may be of different material from the body of the head, and may be and in many cases preferably is made of magnetic material.

What is claimed is:

l. The method of making a magnetic hammer which comprises forming a hammer head from non-magnetic material, forming a bore extending longitudinally of the head from the striking end of the hammer, and forming an opening from the inner end of the bore through the side face of the hammer positioning a permanent magnet in the bore, said magnet being of less length than the bore, sliding the magnet to the inner end of the bore, welding a cap member to the striking end of the hammer to close the bore and form the striking face of the hammer, sliding the magnet into contact with said cap member and introducing a non-magnetic lling material into the bore through said opening to fill the bore and said opening and fix the magnet in the bore.

2. A magnetic hammer having a head provided with a handle opening and formed of a body of non-magnetic material, said head being provided with a chamber forming bore opening to and extending from the striking end of the head part way of the handle receiving opening of the head, a permanent magnet secured therein with its outer end flush with said striking end of the head, a cap member formed of magnetic material permanently secured to the striking end of the head and forming the striking face of the head, said bore and magnet extend ing at substantially right angles to said face, said head consisting essentially of non-magnetic material except for said magnet and cap member, said chamber being of greater length than the magnet, the head being formed with an opening to said chamber rearwardly of the magnet, and means formed of non-magnetic material extending through said opening and into contact with the rear end of the magnet to hold the forward end of the magnet in permanent contact with said cap member.

3. A magnetic hammer having a head provided with a handle opening and formed of a body of non-magnetic material, said head being provided with a chamber forming bore opening to and extending from the striking end of the head part way of the handle receiving opening of the head, a permanent magnet secured therein with its outer end flush with said striking end of the head, a cap member formed of magnetic material permanently secured to the striking end of the head and forming the striking face of the head, said bore and magnet extending at substantially right angles to said face, said head consisting essentially of non-magnetic material except for said magnet and cap member, said chamber being of greater length than the magnet, the head being formed with at least one opening to said chamber rearwardly of the magnet, said opening and the portion of the chamber rearwardly of the magnet being lled with non-magnetic material to maintain the magnet in contact with said cap member.

References Cited in the rile of this patent UNITED STATES PATENTS 29,760 Boeklen Aug. 28, 1860 2,390,339 Ullman Dec. 4, 1945 2,417,762 Koller Mar. 18, 1947 2,528,709 Raymond et al. Nov. 7, 1950 2,550,775 Clark May l, 1951 2,562,714 Hawtof July 31, 1951

Images