US122215A - Improvement in head-blocks - Google Patents

Description

N. F. BVECKWITH.

Improvement in Head Block's.

Patented Dec. 26,1871.-

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NELSON F. BEGKWITH,

' PATENT or OMRO, wIscoNsIN.

IMPROVEMENT IN HEAD-BLOCKS.

Specificationforming part of Letters Patent No. 122,215, dated December 26, 1871.

To all whom it may concern:

Be it known that I, NELSON F. BECKWITH, of Omro, in the county of Winnebago and State of Wisconsin, have invented certain new and useful Improvements in Head-Blocks 5 and I declare that the followingis a full, clear, and exact description thereof, reference being had to the accompanying drawings, in which Figure 1 is a top-plan view of my improved standard. Fig. 2 is a central vertical section of the same; and Fig. 3 is a front elevation.

Similar letters of reference in the several drawings indicate the same parts.

The principal difficulties encountered in sawing logs into boards are as follows, to wit: First,

when a log has been reduced to such thickness that only .sufficient material remains for one or two boards, it is almost impossible to hold it upright upon its edge against the standards upon the carriage during the operation of sawing. The liability of the log to thus turn or slip upon the head-blocks is greatly aggravated if its lower edge next to the standard is wany or rounded off from any cause. For this reason, it is'customary in all saw-mills to leave the last out in the form of a thick plank, affording sufficient bearing-surface to prevent its turning upon the head-block. Two thicknesses of lumber are therefore sawed from the same log or cant. Secondly, the standards employed for saw-mill carriages are usually so constructed to hold the log that, when the latter is to be sawed entirely into'narrow boards of the same thickness, the last two or three are liable to bend during the operation of sawing, varyin g thickness of each more or less, and producing thereby imperfect boards.

My invention has for its object to overcome these difficulties; and tothis end it consists in constructing the standards with wide-bearing faces for the logs, and in providing each with a central vertical slot or mortise, through which a i series of hooks are projected to grasp the log or cant. The lower hook is curved upward to catch into the lower edge of the log next the standard, and the upper hooks are curved downward to catch into the face of the log. The lower hook and the series of upper hooks, therefore, move in -opposite directions to grasp the log between them and prevent it from slipping. The hooks are operated simultaneously by a lever from the back of the standard, and by a suitable system of connecting-bars, as I will presently describe. By this arrangement the upper hooks hold the log securely in contact with the lower hook, while the latter holds it firmly against the standard and prevents it from slipping until the last board is sawed. By constructing the standards with a wide face, and in arranging the hooks to project through a central slot, a broad bearing is formed for the log upon each side of the hooks, sothat when the log is reduced to the thickness of two or three boards, the latterareheld securely against bending while being sawed.

[n the accompanying drawings, A is the standard, constructed with a wide face, B, and adapted to be applied to a carriage in the usual manner. 0 D are the hooks, pivoted in the same vertical line to the side of a metal plate, K, as shown, and arranged to be projected through a vertical slot, E, formed centrally in the wide face B of the standard. The plate K is set off from the side of the standard to a distance about equal to the width of the slot E, so as to form a continuation of said slot, as well to afford a protecting case for the hooks and their attachments as to afl'ord proper supports forthe same. The points" of the hooks O are curved downward, and their inner ends are pivoted to a common connecting-bar, F. Thelower hook D is pivoted at the angle of the standard, with its point curving upward. G is the operating lever, pivoted to the plate K at h, midway between the hook D and the lower one' of the series 0. The book D is connected to the short arm of the lever by the pivoted bar I, and the hooks G are connected to the lever upon the opposite side of its pivot h by means of the bar J, which is either pivoted to the lower hook of the series 0 or to the connecting-bar F. I have thus far described the hooks and their attachments pivoted to the side of aplate,'K; but that is not absolutely essential, as they may be pivoted directly to the side of the standard and the plate K dispensed with.

The operation is as follows: A log or cant is first laid upon the carriage in contact with the face of the standards, two or more of which may be employed, as preferred. The outer end of the operating lever is then raised, projecting the hook D upward through the slot E into'the lower edge of the log, and the upper hooks G downward through the slot into its face. When the lever reaches the perpendicular, the respective points FEICE,

f the connecting-bars F I J are in the same verical line, or nearly so, and the hooks are there- )re locked in place against the possibility of asual displacement. By this means the log is eld firmly against the standards until the saw- 1g is completed, the last board being held as seurely as at the beginning of the sawing. I proose to construct the lower hook of sufficient trength to hold the log, in some cases dispenslg entirely with the upper series, though prefrably using both. To release the last board, it i only necessary to depress the lever which re- ?acts the hooks behind the face B. In this potion, as shown in Fig. 3, they are out of the way t the succeeding log laid against the standards.

While I have shown a standard specially conructed to receive the hooks I do not limit myalf to this construction, as I design to apply win to all varieties of standards, old and new. 'either do I desire to limit myself to the precise rrangement of the operating lever, as it may be rranged to project the hooks when thrown down nd to retract them when thrown up, which results are efl'ected by transposing the ends of. the

. bars I J upon the operating lever.

Having thus described my invention, what I 3. The combination of the supporting guard- 7 plate K with. the slotted standard and the hooks O D and their attachments, substantially as described, for the purpose specified.

NELSON F. BEGKWITH.

Witnesses:

.N. FRANK, J. H. BANKS; (1.30)

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