US221916A - Improvement in surveyorsj targets - Google Patents

Description

S. HASLETT. Surveyors Target.

C Y u r Y wav vl qm. S hllwl "www UNITED. i STATES PATENT OFFICE.

SULLIVAN HASLETT, OF BROOKLYN, NEV YORK.

lMPROVEMENT IN SURVEYORS TARGETS..

Specification forming part of Letters Patent No. 221,916, dated November 25, 1879; application filed April 2l, 1379.

To all whom 'it may concern:

Be it known that I, SULLIvANHAsLETT, of Brooklyn, in the county of Kings and State of New York, have invented a new and useful Improvement in Surveyors Targets; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon, making part of this specification.

This invention is .in the nature of an improvement in surveyors7 targets; and the invention consists in a surveyors target constructed with a micrometer adjusting-screw and clamping-screws, whereby the target may be accurately adjusted .to the divisions on the ,surveyors staff, and whereby the sliding portion of the staif itself may be adjusted, in the manner hereinafter more particularly described.

In the accompanying," sheet of drawings, Figure lis a front view of target and statt; Fig. 2, a side view of `my invention; Fig. 3, a reverse side view of same; Fig. 4, a section through line w m, Fig. l; Fig. 5, a cross-sec tion of adjusting devices, showing micrometer-screw and springs; Fig. 6, a front view of adjusting devices, with sleeves partly in section, in line y y, Fig. 5; and Fig. 7, front view of stalf, showing. interior slidev and interior markings.

Similar letters =of reference indicate parts in the several figures.

In surveying and leveling, the well-known target is ordinarily adjusted to the divisions on the surveyors staff by hand, and the frequent inaccurate adjustment in this Way has led to errors, and also to loss of time in making the adjustment. The same remark applies also to the adjustment of the sliding portion of the surveyors staff-that is, the accurate adjustment of the slide to the divisions of the scale formed between the sliding surfaces of the staff.

To obviate these difficulties I construct my target A, which may be of any desired size or shape on its face, with a bracket or sleeve, B. This sleeve is firmly secured lto the back of the target, and is preferably rectangular in shape. Within the sleeve B is accurately tted a second sleeve, C, which is not' attached like to the target, but which is constructed to permit the surveyor-s stati D to pass through it, with suflicient space between the surface ot' the staff D and the inner surface of the sleeve O to allow the interposition of lia-t springs a I) c d, which are secured within the sleeve C. The sleeve B on one side has formed in it a slot, c, which slot is parallel with the length of the stat't'D, and the sleeve O likewise has a small slot, j, formed in one of its sides, which last-mentioned slot is also parallel with the staff D.

To the sleeve .O is fixed a stud, j', which passes through the slot e in the sleeve B. This stud has screw-threads formed in it', which receive the threads of a screw, g, with a milled head, h, formed on it, and through the sleeve B passes a screw, fi, which screw enters into the slotj in the sleeve C.

To the rear .side of the sleeve B is fixed or formed a projection, 7c, and within this projection is iitted a sliding nut, Z. This nut has made in it screw-threads into which passes a screw, E, working in bearin gs m and a, formed on the rear side of the sleeve O, the screw E being provided with a milled head, o.

The staff D vemployed is the ordinary surveyors staff, with the divisions r on its face, and made in two parts, s and t, which slide together, and also with divisions o on the slide w.

My target, constructed substantially as above described, is operated as follows: It is moved by hand until the dividingliine y on its face is nearly coincident with the marking ou thelscale r on the face of the staff, or as nearly as may be to the height indicated by the surveyor, in which position it is held by turning the clamping-screw g, which forces the spring d against the side of the staff, tightly clamping the target in position. Then, when a more accurate adjustment requires thi-e target to be moved carefully up or down from its clamped position, as before stated, the micrometer-screw E is turned to the right or left, thereby raising or lowering the target with accuracy to a given position on the staff. This raising and lowering of the target is accomplished by the action of the micrometer-screw working through the nut l, which is iixed to the sleeve C, so that as this sleeve is clamped n to the staff by the binding-screw g the sleeve B slides over the surface of the sleeve G, carrying` the target A, which is iiXed to it, as before stated. This action of the micrometer, screw E not only adjusts the target on the staff with great nicety, but it also holds the target iiXed in whichever position it may be adjusted by the action of the screw E.

The purpose of the slot c in the sleeve B is to permit the sliding` movement of the sleeve without interruption from the binding-screw g.

To adjust the sliding parts ot' the staff to the scale v on the slide w, a plate, a2, with a screw-hole formed therein, is countersunk and fastened to the side of the face-section or sliding part s, of the statt', and the sleeve B is moved up to that plate, or the stail is otherwise adjusted so that the screw t' may enter into the screw-hole formed in the plate a2, thereby firmly clamping the sleeve B to the face 0r sliding part s ofthe statt', and when so fixed, by releasing the clamping-screw g and turning the micrometer-screw E, the two sections 0f the staffs and t will be made to slide on each other up or down, as may be desired, till an apprcximately-accurate adjustment of the height of the statt' is obtained. Then by tightening the screw g the accurate adjustment is effected by the action of the micrometerscrew E, which causes the sleeve B to slide up and down on the sleeve C as the screw is turned to the right and left; and since the sleeve B is practically screwed fast to the front sliding4 portion, s, of the staff', as before described, this front portion ot' the staff is carried by the sleeve B by its movement, as before stated.

Vhen adjusting thc target so that this adjustment of the length of the sta-ft' by the micrometer-screw is desired, it is necessary to slacken up the clamping-screw g, so as to permit the two sections of the staii' to freely slide upon each other. The slot j in the sleeve C permits the sleeve C to move up and down unobstructed by the screw The purpose ofthe springs 11,1), and c is to cause the target to slide steadily' without wabbling and with ease on the stai D. The spring` d also assists in that particular, and besides acts as a clamp in connection with the screw g, as hereinbe-fore described.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, .is-

1. A surveyors target, A, in combination` with sleeves B and C, micrometer-screw E, and staff D, substantially as and for the purpose described.

2. In a surveyors target, the combination of a micrometer-screw, E, a clamping-spring, a, and clamping-screw t', substantially as and for the purpose described.

3. In a surveyors target, the combination of a micrometer-screw, E, a clamping or holding screw, g, and sliding sections s and t ot a- `surveyors stati', D, substantially as and for the purpose described.

4. In a surveyors target, the combination of the staff D, the sleeve B, sleeve C, micrometer-screw E, clamping-screws g and t', and

springs a b c d, substantially as and for the purpose shown and described.

SULLIVAN HASLETT. Witnesses:

H. L. WATTENBERG, G. M. PLYMPTON.

Images