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Publication numberUS3329105 A
Publication typeGrant
Publication dateJul 4, 1967
Filing dateJun 3, 1966
Priority dateJun 3, 1966
Publication numberUS 3329105 A, US 3329105A, US-A-3329105, US3329105 A, US3329105A
InventorsMcpherson Paul M
Original AssigneeMcpherson Instr Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Optical support table
US 3329105 A
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Description  (OCR text may contain errors)

July 4, 1967 p MCPHERSON 3,329,105

OPTI CAL SUPPORT TABLE Filed June 5, 1966 l NVEN'l "OR. Palm M JJZFEVZfW/b BY United States Patent 3,329,105 OPTICAL SUPPORT TABLE Paul M. McPherson, Acton, Mass., assignor to McPherson Instrument Corp., Acton, Mass., a corporation of Massachusetts Filed June 3, 1966, Ser. No. 555,057 3 Claims. (Cl. 108-144) This invention relates to the field of support tables, and more particularly to tables used for moving and stabilizing extremely sensitive optical apparatus.

Support tables now in use conventionally have four legs with wheels and four stabilizers by means of which the Wheels are raised equally off the ground for stable support. Lever means or hydraulic means are used to simultaneously actuate the stabilizers to elevate the table. These features, while adequate for many purposes, prove unsuitable for general use with sensitive optical apparatus which must be precisely levelled on fioors customarily a bit uneven, and which must be elevatable to diverse workin heights for use with other apparatus. Moreover, the means used often do not work smoothly, but permit apparatus to be bumped or jarred as it is raised or lowered.

Accordingly, the principal objects of the present invention are to provide a support table which olfers firm and stable support for optical apparatus, which is easily and precisely levelled without loss of stability during levelling, which is elevatable to diverse working heights, which can be lowered or raised smoothly and without jarring or bumping, and which, when mobile, safely and stably transports heavy and costly optical apparatus.

Briefly summarized, the invention is a mobile optical levelling table having a bench structure upon which the optical apparatus is to be placed, and a first set of legs attached to and depending from the bench structure. These legs have casters at their lower ends for mobility. In addition, a second set of three triangularly spaced hollow legs is attached to the bench structure such that the center of gravity of the table is located a substantial distance inside the triangle defined by the legs.'In each of these hollow legs there is an independently adjustable screw-jack means which is extensible downwardly from a position above the casters to a position below the casters, whereby the table may be smoothly raised and precisely levelled, or lowered carefully upon the casters. Each screw-jack means extends into a hollow leg a major part of the length of the hollow leg, so that the table has a wide range of possible elevations.

For the purpose of illustration a typical embodiment of the invention is shown in the accompanying drawing in which:

FIG. 1 is an isometric view showing the table supported for transport by the legs with casters, the screw-jack means being elevated above the casters;

FIG. 2 is an isometric view showing the table supported by-the screw-jack means, the screw-jack means being extended below the casters;

FIG. 3 is a plan view of the table; and

FIG. 4 is a section on line 4-4 of FIG. 3.

In the particular embodiment of the invention chosen for the purpose of illustration, the table has a bench structure 1 comprising a flat top portion 2, a fiat bottom portion 3, and a peripheral skirt 4 extending between the top and the bottom portions. As shown in FIGS. 1 or 2, portions of the top portion, the bottom portion and the peripheral skirt are removed to reduce the weight of the bench structure.

Attached to and depending from the bench structure 1 is a first set of three spaced legs, 1a, 2a, 3a. This first set of legs is spaced to form a triangle; the leg 1a being centrally located at one end of the bench structure 1, and the legs 2a and 3a being located at the corners of the opposite end of the bench structure.

As shown in FIG. 4, each leg 1a, 2a or 3a comprises a hollow tube 5 which fits through a circular hole provided in the bottom portion 3 of the bench structure and abuts the top portion 2. Tack welds secure the tube 5 to the top and bottom portions of the bench structure. In the lower end of the tube 5, and secured thereto by welding or the like, is a cylindrical block 6, to which a swivelling caster 7 is fastened.

-The first set of legs 1a, 2a and 3a stably supports the table when it is transporting optical apparatus. As shown in FIG. 3, the center of gravity of the table is substantially within the projection of a triangle defined by the first set of legs. To further increase stability during transport of apparatus, it is preferable that the first set of legs be susbtantially shorter than the intended operating height of the table. This provides a low center of gravity for the table and apparatus when it is mobile and permits safe negotiation of ramps and uneven surfaces without danger of tipping.

Also attached to the bench structure 1 and depending therefrom is a second set of three spaced legs 1b, 2b and 3b, terminating above the first set of legs. This second set of legs is triangularly spaced as shown in FIGS. 1, 2 or 3, the leg 1b being centrally located between the legs 2a and 3a at one end of the bench structure 1, and the legs 2b and 3b being located at the corners at the opposite end of the bench structure. As shown in FIG. 3, the center of gravity of the table also lies substantially within the triangle defined by this second set of legs, so that either set of legs supports the apparatus stably.

As shown in FIG. 4, each leg 1b, 2b or 3b comprises a hollow tube 9, fitting through a hole provided in the bottom portion of the bench structure, and abutting the top .portion 2 of the bench structure. Tack welds secure the tube 9 to the bench structure. A cylindrical plug 10 is inserted in the upper end of the tube 9 and secured thereto. A hole 11, threaded to receive a machine screw, is provided in the plug 10 and upper portion 2 of the bench structure.

A plurality of cylindrical guide blocks 12 is spaced lengthwise of the interior of the tube 9 and secured thereto by welding or the like.

In each of the hollow legs 1b, 2b and 3b, a screwjack 13 threada-bly engages the guide block 12 so as to be adjustable axially in the tube 9. Each screw-jack extends into a hollow leg a major part of the length of the hollow leg. This permits the table to be raised a substantial distance and provides a wide range of operating heights. At the lower end of the screw-jack 13 a ball-and-socket levelling pad 14 is provided to obtain firm support on uneven surfaces. Just above the levelling pad, gripping means 15 are provided, whereby the screwjack may be rotated and adjusted axially with a wrench or the like. Alternatively, a lever may be attached to the screw-jack to facilitate its rotation and adjustment.

As shown in FIGS. 1 and 4, the screw jacks 13 are extensible upwardly to an elevated position above the bottoms of the casters 7 on the first set of legs. When so elevated, the table is mobile. As shown in FIG. 2, the screw-jacks are also extensible downwardly to a lowered position substantially below the casters, thus raising the table to a desired working height. As described, each screw-jack means is independently and continuously adjustable, which permits the table to be easily and precisely levelled. The provision of exactly three screw-jack means, spaced triangularly about the center of gravity of the table, assures that the table will remain stable during the levelling process. And the continuous, even motion Q of the screw-jacks assures that sensitive apparatus will not be jarred or bumped as the table is raised or lowered.

It should be understood that the present disclosure is for the purpose of illustration only and that this invention includes all modifications and equivalents which fall within the scope of the appended claims.

I claim:

1. A mobile optical levelling table comprising (a) a bench structure (b) a first set of least three spaced legs attached to and depending from the bench structure, said legs having casters at their lower ends,

(c) a second set of three spaced hollow legs fixed to and depending from the bench structure, each of said legs terminating above the first set of legs,

(d) screw-jack means in each of said hollow legs and adjustably extensible downwardly out of said hollow legs from an elevated position above said casters to a lowered position below said casters, the center of gravity of said table being located a substantial distance inside the projection of a triangle defined by said three screw-jack means, each screw-jack means extending into a hollow leg a major part of the length of the hollow leg, and each said screw-jack means being independently adjustable,

whereby said table may safely stably transport heavy optical apparatus when on said casters, and thereafter may be raised by said screw-jack means to operating height and stably levelled.

2. A mobile optical levelling table comprising (a) a bench structure;

(b) a first set of three triangularly spaced legs attached to and depending from the bench structure, the center of gravity of the bench structure lying a substantial distance within the triangle defined by the first set of legs, each of the first set of legs compris- (1) a tube secured at one end to the bench structure; and

(2) a swivelling caster fastened to the opposite end of the tube, whereby the table may safely stably transport heavy optical apparatus when on the casters;

(c) a second set of three triangularly spaced vertical legs attached to and depending from the bench struc- 4 ture, the center of gravity of the bench structure lying a substantial distance within the triangle defined by the second set of legs, each of the second set of legs comprising '(1) a tube secured at one end to the bench structure and terminating above the first set of legs;

(d) screw-jack means in each of the second set of legs and independently adjustably extensible downwardly out of the legs from an elevated position above the casters to a lowered position below the casters, each screw-jack means comprising (1) a plurality of guide blocks spaced lengthwise in the leg and secured therein;

(2) a screw-jack threadably engaging the guide blocks and extending a major part of the length of the leg; and

(3) a levelling pad secured to the lower end of the screw-jack, whereby the table may be raised by the screw-jacks to operating height and stably levelled.

3. A mobile optical levelling table according to claim 2 wherein the bench structure comprises (a) a flat top portion;

(b) a fiat bottom portion; and

(c) a peripheral skirt extending between the top and bottom portions and secured thereto;

and wherein the tubes of both sets of legs extend through holes provided in the bottom portion and abut the top portion, being secured to the top and bottom portions by welds.

References Cited UNITED STATES PATENTS 198,576 12/1877 DAmore 182-l7 X 204,893 6/1878 Gibbons 18217 X 2,360,999 10/1944 Wyen 182-l7 3,232,377 2/1966 Smith 182l7 X FOREIGN PATENTS 280,126 4/ 1952 Switzerland.

DAVID J. WILLIAMOWSKY, Primary Examiner.

FRANK B. SHERRY, Examiner.

G. O. FINCH, Assistant Examiner.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US198576 *Dec 25, 1877 Improvement in fire-escape ladders
US204893 *Apr 12, 1878Jun 18, 1878 Improvement in fire-escape ladders
US2360999 *Apr 8, 1943Oct 24, 1944Wyen Peter APortable scaffold structure
US3232377 *Jun 17, 1963Feb 1, 1966Baker Roos IncAdjustable scaffold
CH280126A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4789121 *May 1, 1987Dec 6, 1988Edward D. GidsegSystem for supporting and adjusting refrigerators and the like
US5653457 *Sep 30, 1994Aug 5, 1997Key Functional Assessments, Inc.Convertible table/cart apparatus
US5967472 *Apr 3, 1997Oct 19, 1999Bsh Bosch Und Siemens Hausgeraete GmbhHeight-adjusting device for an adjusting foot of a household appliance
US6354231 *Dec 8, 1999Mar 12, 2002Anderson Hickey CompanyTable leg with height-adjusting spacer
US7159829 *Jun 18, 2004Jan 9, 2007Kason Industries, Inc.Height adjustable support for food service equipment
US7571887Dec 7, 2007Aug 11, 2009Kason Industries, Inc.Height adjustable support for food service equipment
US8152118Feb 25, 2009Apr 10, 2012Jonathan Jonny MelicLocking and lifting mechanism for safety fence support post
US8590849Aug 9, 2006Nov 26, 2013Jonathan Jonny MelicLocking and lifting mechanism for safety fence support post
US8651448 *Aug 21, 2008Feb 18, 2014Wasyl RosatiMeans of stripping concrete formwork from a concrete surface
US20100288909 *Aug 22, 2007Nov 18, 2010Wasyl RosatiMeans of stripping concrete formwork from a concrete surface
US20110316199 *Dec 4, 2008Dec 29, 2011Wasyl RosatiMeans of stripping concrete formwork from a concrete surface
Classifications
U.S. Classification108/4, 108/136, 248/466, 108/144.11, 248/188.2
International ClassificationA47B91/00, A47B91/02, A47B37/00
Cooperative ClassificationA47B37/00, A47B91/024
European ClassificationA47B37/00, A47B91/02D2
Legal Events
DateCodeEventDescription
Dec 23, 1986ASAssignment
Owner name: BANK OF NEW ENGLAND N.A. (AS AGENT)
Free format text: SECURITY INTEREST;ASSIGNOR:GCA CORPORATION, A DE CORP;REEL/FRAME:004730/0239
Effective date: 19860228
May 22, 1986ASAssignment
Owner name: BANK OF NEW ENGLAND, N.A., AS THE SECURED PARTIES
Free format text: SECURITY INTEREST;ASSIGNOR:GCA CORPORATION;REEL/FRAME:004620/0001
Effective date: 19860228
Jun 15, 1981ASAssignment
Owner name: GCA CORPORTION, A CORP. OF DE.
Free format text: SECURITY INTEREST;ASSIGNOR:SCHOEFFEL INTERNATIONAL CORPORATION;REEL/FRAME:003862/0665
Effective date: 19810504