US3941A

US3941A - Pick fob deessing stone

Info

Publication number: US3941A
Authority: US
Publication date: 1845-03-12
Anticipated expiration: 1862-03-12

Description

"bnr an einer JOHN C. DEXTER, OF IONIA, MICHIGAN.

PICK FOR DRESSING STONE,

Specification of` Letters Patent No. 3,941, dated March 12,` 1.845.

To all 'whom t may concern:

Be it known that I, JOHN C. DEXTER, of Ionia, in Ionia county and State of Michigan, have invented a new and useful Improvement on Mill-Picks for Dressing French Bur-Millstones; and I do hereby declare that the following is a full, clear, and exact description of the construction and opera tion of the same, reference being had to the annexed drawings, making a part of this speciiication, in which- Figure l shows a side view of the instrument when adjusted for use. A, the head, and B, the outer jaw with C, the inner jaw are made of cast iron. A, and B, are cast together in one piece. C, is cast in a separate piece with a channel on the inner side nearly one tenth of an inch in depth and about one and a quarter of an inch in width and extending about seven eighths of the length of the inner jaw C, C, into which channel the point D is inserted in adjusting for use. The point D, is made of the best cast steel, accurately tempered for cutting French bur stone. The thickness of the point D, is one tenth of an inch; the breadth one and a quarter inch; and the length to correspond with the length of the channel made for it inthe jaw C. The position of the point in the instrument when adjusted or use is indicated in Fig. 1, by the dark lines below the ends of the jaws B, and C, and by the dotted lines passing up through the jaw C, and through the head A. The point is kept in order for use by grinding it on a common grindstone; care being taken to grind a bevel equal on both sides of the point so as to preserve the same form as seen in the drawing at Fig. 1. E, the handle, is made of any fine grained, hard wood, and is attached to the instrument by the wrought iron rod F, which runs through it and is screwed into the head by the screw G, and made firm in the handle by the nut H, screwed on at I. e, e, is a thin ferrule of iron or brass designed to strengthen the handle near the head.

Fig. 2 represents the side of the head and outer jaw B, next the handle; also the hole at G, into which the handle is secured.

Fig. 3, represents the inner jaw C, with the point D, placed in its channel. rl, in Fig. 3, and Z in Fig. 1, shows the method of extending the point D, when worn short by use. CZ is a piece of iron of the same of the instrument I have found most ccnvenient in stones. j ,j

To adjust this instrument for use I place the point D into the channel made in C, as seen in Fig. 3 and then slide `it into the socket A Fig. 1, and then, holding the instrument by the handle with the sharp end of the point D upward, I strike the end b, of the jaw B, B, upon some hard substance, as a block of wood, which settles the jaw C, firmly into the socket A, conlining the point D firmly between the jaws B and C, and the instrument is then ready for use. )Vlien I wish to release the point for the my practice of dressing mill purpose of sharpening &c., I turn the sharp end of the point upward and then strike the opposite end of the jaw C, C, on the block of wood which instantly displaces the jaw C, C, and releases the point D.

The invention of this entire instrument I do not claim; but

What I do claim as my invention and desire to secure by Letters Patent, is-

rlhe mode of adjusting and coniining the point D, (Fig. 1,) for use; and releasing the same, when necessary from the instrument; this is effected, 1st by constructing that part of the jaw C, C, (Fig. 1) extending from c1, to c2, (Fig. 1,) in a tapering form; so that the jaw C, C, shall be at c1 about two thirds as thick as at 02,' 2d, by making the hole through the socket A (Fig. 1,) of the same degree of taper as the jaw C, C, and of the proper size to exactly embrace the jaw C, C, when driven home to its place, as seen in (Fig. 1) 3d, by making a channel on the side of the jaw C, G, (Fig. 1,) next to the jaw B, B, about one tenth of an inch deep, about seven eighths the length of the jaw C, C, terminating the channel about one inch from the end c1; 4th, by making the point D7 D, (Fig. l), about o-ne thirty-second part of an inch thicker than the depth of the channel in C, C.

To adjust the point and secure it firmly in the instrument for use, I place the point D into the Channel made in C, C, as seen in Fig. 3, then holding the point in the channel, I slide the point D, and the jaw C, C, into the socket A (Fig. I); then, holding the instrument by the handle with the sharp end of the point upward, I strike the end ZJ of the jaw B, B7 upon some hard substance, as a small block of wood; which by the force of the blow, Causes the jaw C, C, to settle rmly into its socket, and produce a pressure against the point D, which secures itrmly in its plaee.- The instrument is then ready'for use. lVhen I wish to release the point for sharpening, Sac., I hold the instrument by the handle with the sharp end of the point upward, and strike the end 01, of the jaw C, C, upon the block of wood, which instantly displaces the jaw C, C, and releases the point.

JOHN C. DEXTER. lVitnesses:

MASON HENSEY, A. F. CARR.