US2775497A - Adjustable drawing table construction - Google Patents

Description

Dec. 25, 1956 M. M. ALVAREZ ADJUSTABLE DRAWING TABLE CONSTRUCTION 2 Sheets-Sheet 1 Filed Oct. 27. 1.955

m M rN a E 9 Z 0 VV /5 3 N :4 7 A 0 4 M a m 47 n a v M B Dec. 25, 1956 M. M. ALVAREZ ADJUSTABLE DRAWING TABLE CCNSTRUCTION Filed Oct. 27. 1.955 2 Sheets-Sheet 2 Fig. 3

- Fig.4 I06 I04 58 I06 41 X 72 4/02 |4 Manuel M. Alvarez IN VEN TOR.

ADJUSTABLE DRAWING TABLE CONSTRUCTION Manuel MaAlvarez, Los Angeles, Calif assignor of fifty percent to James E. Gonzales, Van Nuys, Calif.

Application October 27, 1955, Serial No. 543,173

4 Claims. (Cl. 311--39) A more specific object of invention in conformance with that set forth above is to provide a novel extensible support leg construction usable for drawing tables which includes a telescopically supported rod member including a peripheral vertically disposed rack portion telescopically received within a tubular support element, and wherein said rack portion is engageable by a spring urged dog element of a readily manipulable and actuated latch assembly.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure .1 is a perspective view of a drawing table incorporating the novel. vertically adjustable leg structure;

Figure 2 is a sectional view taken substantially on line 22 of Figure 1;

Figure 3 is a sectional view taken substantially on line 33 of Figure 1; v

, Figure 4 is a sectional view taken substantially on line 4-4 of Figure 3;

Figure 5 is an explodedperspective view of the housing member of the novel latch assembly of the invention; and

Figure 6 is an enlarged perspective view of the actuating lever of the latch assembly.

Indicated generally at 10 is a vertically adjustable drawing table including a wooden board portion 12 having side frame members 14 and 16 which include an integral intermediate pivot ear element 18 and 20, respectively, and an arcuate slotted guide track element 22 and 24, respectively.

A pair of substantially identical oppositely disposed leg assemblies 26 and 28 are provided beneath the respective pivot earportions 18 and 20 of the drawing board the assemblies 26 and 28 each including an arcuate foot element 30 which includes ground engaging lower end portions, having suitably secured in an upwardly opening intermediately disposed socket portion 32 an extensible support leg assembly 34.

The support leg assemblies 34 include a lower tubular support member 36 telescopically receiving an upper vertically adjustable rod member 38, the upper end of the rod member 38 including a flattened end portion 40 which has a suitable aperture portion therethrough aliguable I with a cooperating aperture portion in the pivot ear portions 18 and 20, the rod members 38 pivotally supporting by means of suitable nut and bolt assemblies 42 the drawnited States Patent 0 ing board 12. The rod 38 includes in vertically disposed relationship a wing nut bolt assembly 44 which extends through a suitable aperture portion therein, the bolt assembly 44 extending through the arcuate guide slot element 22 integral with the drawing board whereby the same may be adjusted about a horizontal axis defined by the bolt assemblies 42.

A suitable transverse foot rest element 46 is suitably secured at opposite disposed portion-s on the tubular sup port members 36 for providing a foot rest for the user of the drawing board as well as rigidifying the drawing table structure.

As most clearly seen in Figure 2, the socket portion 32 of the foot element 30 includes therein a suitable coil spring 48 which is in coaxial alignment with the tubular support member 36 and cngageable with the lower end portion 50 of the rod member 38, said spring aiding in taking up shock resulting from dropping the tubular rod members 38 downwardly toward the foot elements 30 as well as aiding in raising the same. i

Each of the rod members 38 includes a vertically disposed toothed rack portion 52 comprised of a plurality of horizontally disposed abutment teeth 54, see Figure 3, engageable with a suitable dog element of the latch as sembly 56 to be subsequently described.

The latch assemblies 56 include a housing member 58 comprised of a pair of cooperating side portions 60 and- 72 (not shown in portion 62) through which suitable fasteners extend. The portion 62 further includes a horizontally disposed step portion 74 terminating in a vertical wall portion 76 which terminates in a transversely extending notched out portion 78 comprising a horizontal wall I portion 80 and vertical wall portion 82. The portion 76 includes a pair of spaced vertically disposed pivot apertures 84 and 86 spaced on opposite sides of an arcuate lost motion slot portion 88. The member 62 also includes on the side opposite the horizontal wall portion 74 x a horizontal wall portion 90 terminating in an upwardly extending abutment portion 92 having a transverse spring receiving aperture 94 extending therein. The horizontal wall terminates in upwardly extending vertical wall portion 94 intersecting the horizontal wall 80 and in cluding therein a pivot aperture portion 96.

In addition to the fastening elements which will extend through the aperture portions 72 of the housing members, the housing portions 60 and 62 include suitable tapped screw receiving portions 98 extending vertically therethrough which are alignable with suitable aperture portions 100 extending through a cover plate element 102 which secures said portions 60 and 62 in a substantially rigid position, said cover plate element 102 including a central aperture portion 104 reciprocably receiving therein the rod member 38. The plate element will be secured by means of the cooperating aperture portions 98 and 100 by means of suitable fasteners indicated at 106 the portions 60 and 62 may have their outer sides covered by means of suitable cover plates 108 (only one being shown) secured thereon by means of cooperating aperture portions 110 and 112 in the housing members and cover plates, respectively.

An arcuate actuating lever is indicated at 114 and includes a lower hand engaging lever portion 116 which extends out of the housing member, see Figure 3, said lever member having an upper apertured portion 118 pivotally aligned with the pivot aperture portion 84 of housing member portion 62 being pivotally retained therein by means of a suitable pivot pin 120, and including a laterally extending integral trunnion element 122 which is 'gu'id'ingly received in the arcuate slot portion 88 of the member, 62, and which extends through an enlarged aperture portion 124 of a force transmitting link element 126 which is pivotally supported on a pivot pin 128 in the pivot aperture portion '86 and including an upper end portion pivotally connected by means of a suitable pivot element 130 to a transverse force transmitting link 132. The link 132 is pivotally connected at its opposite end by means of a suitable pivot pin element 134 pivotally connected to an upper lever portion 136 of a 'dog element 138 -which is interrncdiately pivoted at 140 in the pivoted aperture portion 96 of member 62, the dog element 138 including a lower lever portion 144, the other end of said compression spring extending into the aperture portion 94 in member 62. The compression spring accordingly tends to rotate the dog element 138 about the pivot 140 in a clockwise direction urging a latch portion 136 thereof into intersecting relationship with the toothed rack 52 on the rod element 38, thus retaining the table in a vertically adjusted position.

It is believed readily apparent by exerting pressure on the handle or lever portion 116 of the actuating lever, the force transmitting links 126 and 132 will be moved toward the left as seen in Figure 3 and the dog element 138 will be pivoted about the pivot portion 140 thereof overcoming the spring pressure of spring 144 resulting in a rod member 38 being freely reciprocable in the tubular support 36 permitting ready adjustment thereof.

The lever portion 116 includes a forward cam or braking surface 147 and as the lever portion 116 is pivoted about the pin 120, the braking surface v147 will engage the side portion of rod 38 opposite the rack portion and to thus prevent a sudden descent of the drawing board as well as aiding in the vertical adjustment of the drawing board.

It will be noted that the rod members 38 include a relatively enlarged notched out portion 148 in alignment with the rack portion 52 for apprising the user of .the table as to when the outermost or highest adjusted position of the rod members 38 has been reached.

Various positional directional terms, such as front, rear, etc., are utilized herein to have only a relative connotation to aid in describing the device and are not intended to require any particular orientation with respect to any external elements.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. An extensible support leg construction for use in vertically adjustable drawing tables comprising a tubular support member telescopically receiving .in one end portion a vertically adjustable support rod, said rod including an intermediate vertically disposed tooth rack portion, and a latch assembly carried on said one end portion of said tubular member, said latch assembly including a housing member secured on said tubular member in circumposed relationship to the rod member, a vertically pivotal actuating lever extending from one side of said housing member, a vertically pivotal dog element pivotally supported in said housing and including a latch portion intersectingly engageable with the tooth rack portion on said rod member, spring means engageable with a first lever portion of said dog element for urging the latch portion into locking engagement with said rack tooth portion, force transmitting linkage means operatively connected between said actuating lever and a second lever portion of said dog element for transmitting force to actuate the same upon overcoming said spring means, and brake means on said actuating lever engageable with the rod member when the latch portion is disengaged from the rack tooth portion.

2. In an extensible support leg construction as set forth in claim 1 including a resilient shock absorbing spring coaxially disposed in a lower end portion of said tubular support member for engagement with a lower end portion of said support rod.

3. A vertically adjustable drawing board comprising a drawing board, a pair of extensible support leg assemblies secured in-depen'ding relationship from opposed side edge portions-of said board, each of said support leg assemblies comprising a tubular support member telescopically receiving in one end portion a vertically adjustable support rod, said rod including an intermediate vertically disposed tooth rack portion, and a latch assembly carried on said one end portion of said tubular member, said latch assembly including a housing member secured on said tubular member in circumposed relationship to the rod member, a vertically pivotal actuating lever extending from one side of said housing member, a vertically pivotal dog element pivotally supported in said housing and including a latch portion intersect-ingly engageable with the tooth rack portion on said rod member, spring means engageable with a first lever portion of said dog element for urging the latch portion into locking engagement with said rack tooth portion, force transmitting linkage means ioperatively connected between said actuating lever and a second lever portion of said dog element for transmitting force to actuate the same upon overcoming said spring means, and brake means on said actuating lever engageable with the rod member when the latch portion is disengaged from the rack tooth portion.

4. A vertically adjustable drawing board as set forth inclaim 3 including a resilient shock absorbing spring coaxially disposed in a lower end portion of said tubular support member for engagement with a lower end portion of said support rod.

References Cited in the file of this patent UNITED STATES PATENTS 427,223 Carr May 6, 1890 522,508 Jones July 10, 1894 709,612 Smith Sept. 23, 1902 922,565 Cole May 25, 1909 928,752 Hawley July 20, 1909 1,048,143 Franke Dec. 24, 1912 1,075,323 Benjamins Oct. 14, 1918 2,646,322 Laxo July 21, 1953

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