US696401A - Lateral adjuster for surveying instruments. - Google Patents

Description

No. 696,401. Patented Apr. I, |902.

C. L. BERGER.

LATERAL ADJUSTER FR SUHVEYINE INSTRUMENTS.

(Application fled Sept. 25, 1901.) (No Model.)

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SPECIFICATION forming part 0f Letters Patent N0. 696,401, dated April 1, 1902. Application filed Septemberz, 1901. Serial No. 76,516. (No model.)

To @ZZ whom it may concern..-

Be it known that I, CHRISTIAN L. BERGER, a citizen of the United States, residing at Boston, county of Suffolk, State of-Massachusette, have invented an Improvement in Lateral Adjusters for Surveying Instruments, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

Myinvention relates to the base portion of a surveying instrument, and is more particularly adapted to mining-transits, being intended to provide means for quickly shifting the transit horizontally after it has been properly leveled and adjusted without disturbing said adjustment. j In general, surveying instruments have been moved laterally relatively to the tripod in two ways, one way being to move the upper part of the instrument relatively to the base and the other way being to move the instrument and its base bodily, the former, however, resulting in placing the telescope and adjacent parts eccentric to the vertical axis of the instrument, and hence in that respect in improper position for usual work, especially mining-work, and the latter, al- 'though not subject to the last-mentioned objection, being, however, of such construction that precision of movement and maintenance of the instrument adjustments could not be relied upon. AccordinglyI have devised the special means, which are more fully set forth in the following description, for enabling the operator to be sure at all times that when once adjusted and leveled the instrument, although moved laterally, will maintain its said adjustments, and to know also that the lateral movement takes place with perfect precision, as intended.

In the drawings, in which I have illustrated a preferred embodiment of my invention, Figure l is a perspective view of a usual surveying instrument having one form of my invention applied thereto. Fig. 2 is an enlarged central vertical section of the most complete form of my invention. Fig. 3 is a right-hand side elevation thereof, parts being broken away. Fig. 4. is a sectional view similar to Fig. 2, showing a simple form of the in vention. Fig. 5 is a vertical cross-sectional detail on the line 5, Fig. 4; and Fig. 6 is a bottom plan View, parts being broken away.

For convenience of illustration I have shown a portion of a usual transit A, mounted on a4 usual tripod a, the former containing a usual post a', leveling-screws a2, base-plate a3, centrally apertured at co4 to permit usual lateral adjustment of the base a5 of the supporting-post, and the tripod is provided at its upper end in usual manner with a threaded shoulder or ring as. Preferably the threads of the plate a3 correspond to the threads of the ring a, so that when desired the intermediate device (which constitutes my invention) may be removed and the plate a3 may be screwed onto the ring a6 in its usual position. My invention, as already stated, resides in providing special means between the plate a3 and the tripod-ring a6 for accurately shifting the superposed instrument one way or another precisely as required, this feature being of particular value in mining-work below ground, although I do not limit the same to this use.

In mine-surveying the work is sometimes done in the dark or partial darkness and the leveling of the instrument by the aid of a faint light, and proper adjustment thereof consumes a great deal of time, patience, and skill, so that when it is once accomplished it is of peculiar advantage to retain the adjust ments. For example, in getting the range of two plumb-lines, which may be suspended in usual manner from the top of a vertical shaft, the plumb-bobs being held stillin buckets of molasses or in other well-known manner, the surveyor first sets up his tripod as nearly in correct position as he can judge and as may be 4permitted by the situation. He then gets the instrument more accurately in line by means of the telescope, and, having done so, levels the instrument; but in doing so he throws the telescope out of line. If, now, the instrument is of the ordinary kind, as shown in the upper portion of Fig. l, he must slightly loosen the leveling-screws a2, so as to shift the instrument-post a5 relatively to the plate a3, and thereby bring the telescope back approximately into line.. This, however, has destroyed the accurate leveling of the instrument, and therefore it must again be leveled. Bearing in mind that this IOO all takes place in comparative darkness with only at least a glimmer of light, it will at once be seen that this destroying of the proper leveling of the instrument becomes very serious. To prevent this difficulty, I provide a guideplate Z1, provided centrally with threads b', fitting the ring a, so that it may be screwed rigidly in place, and on this plate I mount a slide-plate b2, which may be provided in the simpler form of my invention with an annular flange b3, threaded to correspond to the ring a6 for receiving the base-plate a3 of the instrument. In this case the instrument has a lateral movement in one direction by reason of the slide-plate b2 moving over the guideplate b. Preferably, however, a lateral movement is provided also in an opposite horizontal direction, this result being accomplished, as herein shown, by providing on the upper side of the slide-plate b2 a guideway b3, similar in general construction tothe guideplate b, and on this guideway b3 is fitted a second slide-plate b4, which is provided with an annular threaded flange b5 for receiving the base-ring c3 of the instrument.

Referring further to the consti-notional details of the device, it will be seen that the edges of the guides b b3 are beveled or oblique and that the slide-surfaces of the plates b2 b4, which bear on said oblique surfaces, are also correspondingly oblique, thereby insuring a permanently accurate it and also providing a construction which makes it impossible for drib or moisture to reach the bearing-surfaces. Absolute accuracy of adjustment is secured by providing bearing-'screws b in lthe slideplates to bear against the adjacent top surface 'of the guides, as clearly shown in Figs. l and 5.

On its under side the slide-plate b2 is provided with retaining-screws b', which engage the under sides of the adjacent edges 'of the plate b, and for the same purpose screws bs are provided to engage a narrow flange bf of the plate b4 when the latter is employed. In

this manner the instrument may be kept in l true position precisely as required. At one or b'oth ends, the. latter giving the greatest precision, I provide operating screws b, i working in the threaded ends Z910 of the plates b and b4 and bearing against apertured projections Z112 from the superposed slides, these screws being provided with suitablethumbnuts or other turning means Z213. Preferably, also, each screw carries an accurately-spaced indicator bm, said indicator, as herein'shown', having points 1915, located forty-five degrees from each other, for coperation with a projection bw on the adjacent sliding member, so that in the comparative darkness the operator may know precisely how far to one side or the other he shifts his instrument simply by feeling the number of points of the indicator which he turns past kthe projection 1916.

From the above description the operation of my improved lateral adjuster willl be readily understood. The operator wishin g to do underground work simply takes his usual instrument and separates the upper portion at the base-plate a3 from the tripod and then screws onto the latter my attachment and places the upper part of the instrument on top thereof, screwing the base-plate a3 on the liange b5 in case the more complete form of the device is used or on the ring b3 in case the simpler form shown in Fig. 4 is employed. Having adjusted his instrument in usual manner, as required, he now shifts the entire instrument with precision to the left or right, forward or backward, as the case may be, by simultaneously turning in reverse directions the opposite thumb-screws Z113, or one of them only in case the other is omitted,and by counting the number of points Z915 which turn past his thumb resting on the projection 1916 he knows the exact distance to which the instrument is shifted. In case he should desire to tip the instrument slightly one way or the other or take up any wear of parts, he correspondingly adjusts the screws b or such of them as may require it.

While I have herein shown and described my invention in all its preferred details, I wish it understood that, excepting as otherwise required in the claims, I do not limit my invention thereto, as many changes in construction and arrangement of parts may be resorted to within the spirit and scope of my invention.

Having described my invention, what I claim as new, and desire to secure by Letters Patent of the United States, is

l. A lateral adjuster for mining-transits, comprising a guide-plate provided centrally with means for rigidly securing the same on a vusual tripod, a slide-plate mounted thereon, said two plates being mutually provided with cooperating ways for maintaining accurate direction of movement, a thumb-screw in engagement with said two plates for accurately moving the top plate on the bottom plate, and means for mounting above said top plate a mining-transit- 2. A lateral adjuster for mining-transits, comprising 'a 'guide-'plate provided centrally with means for rigidly securing the same on a usual tripod, a slide-plate mounted thereon, said two plates being mutually provided with co'peratingv-'ays for maintaining accurate direction of movement, a thumb-screw in engagement with said two plates for accurately l moving the top plate on the bottom plate,

said top plate being provided on its upper side with guideways extending transversely to the direction of movement of said plate on the guide-plate below, a topmost guide-plate mounted on said guideways and shaped on its under surface to t on said guideways, means for moving said topmost plate on said guideways, and means above said topmost plate for securing thereto the instrument proper.

3. In a mining-transit, means located between the instrument proper and the tripod IOC IIO

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for shifting the instrument bodily in one direction in a horizontal plane, and means for similarly shifting said instrument bodilyin a direction transversely thereto.

4. In a mining-transit, means located between the instrument proper and the tripod for shifting the instrument laterally in a horizontal plane, and means angularly shaped to indicate, by feeling, the extent of said lateral movement.

5. In a mining-transit, means located between the instrument proper and the tripod for shifting the instrument laterally in a horizontal plane, said means includingastationary part, a thumb-screw, and an indicator rotative therewith containing coarse spacingpoints for enabling the operator to tell, by feeling, the extent of rotation of said screw by reference to a relatively stationary part.

G. A lateral adjuster for mining-transits, comprising a guide-plate provided centrally with means for rigidly securing the same on a usual tripod, a slide-plate mounted thereon,

said two plates being mutually provided with coperating ways for maintaining accurate direction of movemenua thumb-screwin engagement with said two plates for accurately moving the top plate on the bottom plate, an indicatorjcapable ofreadily indicating by feeling, carried by said thumb-screw for indicating the extent of rotation thereof, and means for mounting above said top plate a mining-transit.

7. A lateral adjuster for mining-transits, comprising a guide-plate provided centrally with means for rigidly securing the same on a usual tripod, a slide-plate mounted thereon, said two lplates being mutually provided with cooperating Aways for maintaining accurate direction of movement, a thumb-screw at each end of and in engagement with said two plates for accurately moving the top plate on the bottom plate, and means for mounting above said top plate a mining-transit.

8. A lateral adjuster for mining-transits, comprising a guide-plate provided centrally with meansforrigidly securing the same on a usual tripod, a slide-plate mounted thereon, said guide-plate having its opposite sideedges beveled, and said slide-plate having at its opposite edges depending portions beveled on their inner sides to rest on the beveled edges of the guide-plate, means retaining said two plates permanently together, independentlyoperable adjusting devices for adjusting the bearing-surfaces of the two plates with relation to each other, positive means for accurately sliding the top plate on the bottom plate, and means for mounting the instrument proper above the top` plate.

H 9. A lateral adjuster for mining-transits, comprising a guide-plate provided centrally with means for rigidly securing the same on `a usual tripod, a slide-plate mounted to slide on said guide-plate, guiding means for Inutually guiding said plates in relative longitudinal movement, a transit proper mounted on said slide-plate and comprising usual telescope-leveling devices, dac., and meansfor positively moving the top plate on the bottom platete any predetermined extent required.

-In testimony whereof I have signedmy name to this specification in the presence of two subscribing witnesses.

CHRISTIAN nBEReER.

l Witnesses:

GEo. H. MAXWELL, GEO. W. GREGORY.

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