US2497933A - Carpenter's transit - Google Patents

Description

Edm 211 119% c. E. DEVERS CARPENTERS TRANSIT Filed Dec. 26, 194-5 INVENTOR 23 CHARLES E. DEVERS ATTORNEY .upwardly extending tabs Patented Feb. 21, 195

UNITED STATES" PATENT OFFICE 4 Claims.

This invention relates to a surveying instrument or carpenters transit.

One object of the invention is to provide a telescopic sighting instrument in a form convenient for use by carpenters and the like. Another object is to provide a surveying instrument which may be mounted for use upon structural members around a building under construction. Another object is to provide an inexpensive and compact instrument which may be used for establishing levels, for measuring vertical and horizontal angles, and for aligning structural members and the like. These and other objects are attained by my invention which will be undersists of an instrument body H having a circular table portion l2 from the center of which a shaft l3 extends downwardly, and from the periphery of which an upright supporting member 14 extends upwardly in the opposite direction from the shaft. 40 provided in the supporting means l5. This supporting means I5 has an upper cylindrical part I6 upon the top flat side of which rests the underside of the circular table l2. The supporting means I5 is provided below the cylindrical part [6 with a spherical portion which forms a ball I! which provides a ball and socket type universal joint with a socket member l8. The socket member l8 above the portion engaging the ball I! has 19 into which are threaded thumb screws '20 directed against a narrowed neck portion 2| of the supporting means I5, and by means of which the vertical position of the shaft I3 and the cylindrical part It may be adjusted, thereby positioning the circular table [2 of the instrument body I l. The socket member I8 is provided with a lateral extension 22, preferably square in cross section, adapted for attachment to the clamp member 23 by which the whole instrument may be attached to upright or horizontal structural members of a building or the like. The clamp member is removably attached to the lateral extension 22 by the set screw 24. The socket member is conveniently made in halves for convenience in assembling around the The shaft I3 is adapted to rotate in a hole clamping device permits the easy attachment of "is provided with indices showing the degrees spherical portion of the base, the two halves being means It is extended below the spherical portion I! to provide a neck 26 which is conveniently threaded for attachment to a tripod or the like when this is desired. The lower end of the shaft I3 is provided with a threaded portion 21 upon which the lock nut 28 may be threaded to lock the relative positions of the shaft 13 and the supporting means l5.

The circular table [2 has mounted thereon at right angles to each other spirit levels 29 and it is also provided with a magnetic compass '30 which 'is centered with the axis of the shaft [3. A telescopic sighting tube 3| preferably provided with cross hairs, is pivoted to the upright [4 by means of the pivot 32 which is mounted'in a hole in the upper end of the support member I4 and is adapted to be locked in any selected position by means of the thumb nut 33. The pivot 32 is provided with an index hand 34, whose point moves over a scale 35 showing the angle of inclination in either direction from vertical of the tube 3|. The tube is conveniently provided with a spirit level 36 which is mounted in a slot 31 provided in the sighting tube case. An indexing pointer 38 is conveniently provided on the periphery of the circular table 12 to indicate the angular movement of the circular table relative to the upper cylindrical portion of the supporting means whose periphery is conveniently of approximately the same diameter as'that of the circular table and circle.

The advantages of my instrument are that it is simple and inexpensive and may be used conveniently by a carpenter'or other mechanic in aligning and levelling which is necessary in ordinary building construction. The provision of the the instrument to structural members of the building and the instrument may be readily aligned either vertically or horizontally by convenient thumb screw adjustments using the spirit levels on the table and on the sighting tube for this purpose.

I claim:

1. A surveying instrument comprising a body portion including a rotatable instrument table having an underside flat bearing surface, a telescope support means extending upwardly from the edge of said table, and a shaft extending downwardly from the center of said table; a supporting means having a cylindrical portion adapted on its upper end to form a bearing surface for the under surface of said table, a spherical portion, a narrow neck portion between said cylindrical and said spherical portions, and a hole extending centrally through all said portions adapted for turning said shaft therein; a socket member adapted to partly enclose said spherical portion of the supporting means to form a ball and socket universal joint, said socket member being provided with tabs with radial adjusting screws disposed adjacent said neck portion of the said supporting means between the spherical portion and cylindrical portions thereof, a telescopic sighting tube horizontally pivoted midway between its ends to said upright support means on said body portion; and adjustable clamp means attached to said socket member, said clamp means being adapted to support said instrument on a structural member of a building or the like.

2. A surveying instrument comprising a body portion including a rotatable instrument table having an underside flat bearing surface, a telescope support means extending upwardly from the edge of said table, and a shaft extending downwardly from the center of said table; a supporting means having a cylindrical portion adapted on its upper end to form a bearing surface for the under surface of said table, a spherical portion, narrow neck portions above and below said spherical portion, and a hole extending centrally through all said portions adapted for turning said shaft therein; a socket member adapted to partly enclose said spherical portion of the supporting means to form a ball and socket universal joint, said socket member having tabs with radial adjusting screws disposed adjacent said neck portion of the said supporting means between the spherical portion and cylindrical portions thereof; means associated with the lower narrow neck of said supporting means to adjustably fix the relative angular positions of said shaft and said supporting means; a telescopic sighting tube horizontally pivoted midway between its ends to said upright support means on said body portion; and adjustable means attached to said socket member, said clamp means being adapted to support said instrument on a structural member of a building or the like.

3. A surveying instrument comprising a body portion including a rotatable instrument table having an underside fiat bearing surface, a magnetic compass centrally positioned on said table, two spirit-level tubes arranged at right angles to each other near the edge of said table, a telescope support means extending upwardly from the edge of said table, an index marker on the. edge of said table, and a shaft extending downwardly from the center of said table; a supporting means having a cylindrical portion 1 ing means between the spherical portion and cylindrical portions thereof; a telescopic sighting tube having a longitudinal spirit level tube mounted thereon, said sighting tube being horizontally pivoted midway between its ends to said upright support means on said body portion, and having an index hand movable over a scale on the support means for indicating the angle of inclination of said sighting tube; and adjustable clamp means attached to said socket member, said clamp means being adapted to support said instrument on a structural member of a building or the like.

4. A surveying instrument comprising a body portion including a rotatable instrument table having an underside fiat bearing surface, a telescope support means extending upwardly from the edge of said table, and a shaft extending downwardly from the center of said table; a supporting means having a cylindrical portion adapted on its upper end to form a bearing surface for the under surface of said table, and a hole extending centrally therethrough adapted for turning said shaft therein; a telescopic sighting tube horizontally pivoted midway between its ends to said upright support means on said body portion, adjustable clamp means adapted to engage a structural member of a building or the like; and universal joint means adapted to adjustably attach said clamp means to said supporting means.

CHARLES E. DEVERS.

REFERENCES CITED The following references are of record in the file of this patent:

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