US2162672A - Folding table leg latch - Google Patents

Description

June 13-, 1939. I JQHANNSEN 2,162,672

FOLDING TABLE LEG LATCH Filed Oct. 27., 1936 H ll-t Una J0 HFIIVNSE/Y IN V EN TOR.

ATTORNEY Patented June 13, 1939 iJNiTED STATEE)? oFFies FOLDING TABLE LEG LATCH Application October 27,

4 Claims.

My invention broadly relates to a collapsible ironing-board stand and is more particularly directed to improved latching devices that may be associated with the so-called front leg of a threelegged stand of this kind.

The refined appurtenances herein disclosed are especially applicable to a folding table structure of the bipartite or knuckle jointed type of front leg such as has been more explicitly set forth in .my Patent No. 2,050,846, issued August 11, 1936, and the like purposes. The same latch mechanism likewise finds application to a solid front leg disposition when similarly linked for coordinated movement with a rear leg structure.

The object of the present invention is to provide for an improved latch device of the character indicated that is located in the medial region of the front leg and there fully exposed to view in erected table position, said latch being designed to overcome certain operative difficulties that may be encountered by inexperienced users in the manipulation of the aforesaid foldable table or the like collapsible stand.

Embodied herein are also detailed structural features arranged to promote the end in view. Reference is had to the accompanying one sheet of drawings which are illustrative of alternative embodiments, and in which drawing:

Fig. 1 represents an elevational front end view of an erected ironing board assembly whose bipartite front leg is equipped with by latch devices, and Fig. 2 is a side view thereof.

Figs. 3 and 4 respectively detail such devices in enlarged scale, while Figs. 5 and 6 similarly show 'a modified or rigid front leg provided with the same style of latch devices.

Referring more specifically to Figs. 1 and 2 as one exemplification of an ironing table, this comprises a top board 9 and a pair of metallic rear legs l0 and II of which the respective upper end regions are pivotally bracketed to said board at E2 in a conventional manner. Complementary straps'such as l3 may be attached to each rear leg and are preferably disposed to bring about a lateral spread between said legs when the table is erected The so-called front leg shown in Figs. 1 and'2 is of the bipartite type comprising a thigh section or upper leg portion l4 and a shank section l5 that are pivotally adjoined. by the knee. fulcrum or subsidiary pivot I 6 preferably located between the respective ends of said upper leg portion. Such lower front leg portion is herein made to serve as a component of a certain toggle linkage presently to be defined. The upper end of the 1936, Serial No. 107,779

thigh section may be fixedly attached to a suspension plate I? pivotally mounted at l8 underneath the top board in a forwardly spaced relation to the rear leg structure. As detailed in Figs. 3 and 4, the thigh and the shank sections may respectively be stamped up from sheet metal into separate cross-sectionally trough shaped components i4 and [5.

Each such leg section may comprise a pair of mated flanges such as I9 or 20 of which one such flange pair may extend onwardly beyond the knee fulcrum or the like subsidiary pivot it so as to overlappingly nest the other section therein when said sections are axially aligned in erected leg position. My latch devices are disposed to releasably retain such aligned sections in the manner indicated by full lines in Fig. 3. Such fulcrum I6 is preferably entered intermediate the ends of the upper leg portion it through both flange pairs 59 and 20 as in Fig. 4.

Each rear leg is further provided with a supplementary pivot 2i disposed between the respective leg ends and the front leg shank section G5 has a toggle pivot 22 located contiguous to said knee fulcrum or subsidiary pivot [6, as shown. These pivots may be operatively coordinated for simultaneous front and rear leg move ment by the use of companion brace rods or links 23 that respectively interconnect the pivot It with the supplementary rear leg pivots 2!. The leg hook-up is herein completed by a pair of relatively long guide rods or links 24 of which corresponding ends may be pivoted to the toggle pivot 22 and the other ends may by the use of a bracket be pivotally attached to the top board coincident with or closely adjacent to the rear leg end pivot [2. It is not essential however that the front leg attachment of said brace link 23 be hooked up to the extremities of the knee fulcrum since it may likewise be pivotally secured to the thigh section at a point displaced from said fulcrum by an independent link pivot.

By virtue of thedescribed linkage, my bipartite front leg may by the manipulation of its shank section 55, be partially collapsed into the dotted position represented in Fig. 2, which in turn carries the rear legs therewith until all the table legs become superimposed flatwise against the top board. In practice, it has been found that 'an unskilled user not'infrequently attempts to forcibly fold said shank while it remains latched to its. thigh section and that the resulting cocking thrust imposed upon the locking bolt is likely to set up an undue binding effect which the present improvements aim to overcome.

of the front leg shank portion.

The latch mechanism disclosed in my above identified patent was arranged with a manipulative resilient latch strip that directly carries a retractible locking pin, said strip when pulled away from a leg flange serving to release said pin out of latched engagement.

In order to allow of a reversed mode of actuation, I now provide for a manipulative lever end that may be pressed inwardly toward a leg flange and thereby afford a more effective latching device capable of comfortably withdrawing such locking pin by an intermediary leverage or pry when manipulated against any normal binding thrust, even when the cited leg folding operations are performed in incorrect sequence.

To this end, the Figs. 3 and 4 style of front leg may be equipped with a dished resilient latch strip 26 of which the respective ends may be apertured. One such apertured end may be arranged beneath the stub end of the brace link 23 and have the knee fulcrum it entered therethrough as shown. Superimposed upon and riveted to said strip is a flat manipulative pry lever 21 of which the actuated portion 21A may project axially lengthwise of the thigh section M. The retractible toe end of this multiplying lever or pry carries a round nosed or otherwise pointed locking pin or retractible bolt 28 that slidably operates in mated flange holes such as 29 and (see Fig. 4), said holes being located to fall into registry when the front leg sections are axially aligned.

Such tiltable lever 21 may be hingedly mounted by the strip 26 so as to constitute a fulcrum mounting disposed adjacent to the lever toe end. By depressing the manipulative lever end toward the leg flange into its dotted position, my selflocking bolt 28 will be forcibly withdrawn from its aperture 39 located intermediate the terminals The bipartite legs may thereupon be freely folded, it being the intent to initially release said locking pin prior to exerting the required cocking tilt upon the erected shank section 15. However, should the sequence of these operations be inadvertently reversed, sufflcient multiplying leverage is still afforded to effectively release my latch pin. The depressible lever end 21A may be conspicuously inscribed with the word Push to call attention to its purpose on part of uninitiated users. The face of said lever is preferably given a Z-like contour of which the end 21A is offset in longitudinal alignment with respect to the toe end, as shown. Such disposition clears the stub end of the brace rod 23 and also affords access for riveting a head on the adjacent tip of the fulcrum pin l6 when fabricated from rod stock. It will be observed that when the manipulative lever end 21A is depressed to retract its locking pin, the latter still remains in engagement with the flange hole 29 and thus prevents rotation of the fixed latch strip end about its retaining rivet l6.

Assuming the front leg sections l4 and IE to be axially aligned in their erected position, then the latch strip 26 will cause the locking pin 28 to automatically drop into the flange hole 30 whenever its mated hole 29 falls into registry therewith. The bifurcated front leg will then be held rigid for use. By pushing inwardly upon the lever end 21A, the retracted locking pin allows the shank section 15 to unobstructedly turn about its fulcrum it into and through its dotted position IE to bring about a full collapse of the table understructure, as will be understood.

Referring now to Figs. 5 and 6, this shows substantially the same style of latch mechanism except that the previously described thigh has now been extended to constitute a channel shaped rigid or unitary front leg 3|. As a further modification, the previously described shank section is here cut ofi to constitute a shortened link or rocker 32 that is apertured at 4!] intermediate such rocker terminals. One end of such shorter link is also apertured to mount the subsidiary pivot 33 therethrough. The respective forward terminals of the brace rods 34 are carried to such pivot. The opposite end of the relatively short link 32 may be flattened as shown and provided with a toggle pivot 35 that mounts the forward extremities of the relatively long guide rods 36. The links comprised in such jointed toggle are essentially equivalent in structure and purpose to the corresponding members l5 and 24 of Fig. 2 where a portion of the front leg shank is utilized as an apertured toggle component of which one terminal is mounted to turn about its subsidiary pivot It.

In the present instance, the terminal spacing of the guide rods 36 are kept sufliciently close to freely enter within the flange confines of the rigid front leg 3!. Such multiplying latch lever 31 may again be tiltably mounted by a leaf spring 38 and have a retractible locking pin 39 associated therewith. Intermediate the arm ends, there is provided a hole 40 into which said pin automatically drops when the arm 32 assumes axial alignment with the rigid front leg 3!. The hookup of the guide and brace rods are otherwise substantially identical with those of the Fig. 2 exemplification so as to cause the table legs to similarly collapse alongside the board face. When operatively latched, either alternative structure prevents a relative collapsing movement on part of the brace and guide rods and hence, fixedly retains the table legs in erected position, until released. My manipulative lever grip makes plainly evident how such latched leg gear is intended to be released.

Other advantages inherent in my improved devices are believed apparent to those skilled in this art, it being understood that the same underlying latching principle may be associated with other than'ironing board stands and that various modifications in design may be resorted to, all without departing from the spirit and scope of my invention heretofore described and more particu larly pointed out in the appended claims.

I claim:

1. In a collapsible table adapted to unfold into erected position, a top board, a front leg portion of which one end is pivoted to the board, a subsidiary pivot disposed between the ends of said front leg portion, a rear leg structure having one end pivoted to the board in spaced relation to the pivotal attachment of the front leg portion, supplemental pivot means disposed between the respective ends of the rear leg structure, brace rod means extending between the subsidiary pivot and the supplemental pivot means, a toggle jointed linkage comprising a pair of links of different lengths with a terminal of one such link pivotally adjoined to a terminal of the other link and which shorter link is apertured intermediate the length thereof, the free terminal of the shorter link being mounted upon the subsidiary pivot and the free terminal of the longer link being pivotally bracketed upon the board contiguous to the attachment of the rear leg structure, and a latch mechanism including a manipulative pry lever pivotally mounted on the front leg portion in a location exposed to view when the several table legs are erected, said lever being equipped with a shiftable bolt that in erected leg position interlockingly engages the aperture of said short link and which mechanism is so proportioned and arranged that a manipulation of its lever withdraws the engaged bolt from said aperture. 7 V

2. In a collapsible table adapted to unfold into erected position, the combination of a top board, a channeled front leg of which one end is pivoted to the board, an apertured rocker arm of which one end is pivotally attached to and adapted to be received within the channeled confines of the front leg when said leg assumes its erected position, guide link means pivotally interconnecting the board to the other end of the rocker arm, a rear leg structure having one end thereof pivoted to the board in spaced relation to the pivotal attachment of the front leg, supplemental pivot means disposed between the respective ends of said structure, brace link means extending from the supplemental pivot means and pivoted to the front leg, and a latch mechanism including a tiltable lever pivoted between its ends to the medial region of the front leg and having a releasable bolt associated with one lever end region that retractibly engages the aperture of said arm in erected leg position, the opposite lever end region being manipulative to release the locking bolt and which lever is exposed to view in erected table position.

3. In a collapsible table adapted to unfold into erected position, a top board, a channeled front leg portion having complementary flanges, one end of said front leg portion being pivotally bracketed to the board, a subsidiary pivot spanning said flanges and disposed between the ends of said front leg portion, a rear leg structure having one end pivoted to the board in spaced relation to said pivotal bracket, supplemental pivot means disposed between the respective ends of the rear leg structure, brace rod means extending between the subsidiary pivot and the supplemental pivot means, a toggle jointed linkage comprising a pair of links of different lengths with a terminal of one such link pivotally adjoined to a terminal of the other link and which shorter link is apertured intermediate the length thereof, the free terminal of the shorter link being entered between said flanges for operative connection to the subsidiary pivot and the free terminal of the longer link being pivotally bracketed upon the board contiguous to the attachment of the rear leg structure whereby said apertured short link in its erected table position assumes substantial alignment with respect to the channeled front leg portion, and a latch mechanism including a spring retained pry lever pivotally mounted upon an exterior face of one such fiange and further including a lever actuated bolt slidably entered through said one flange, said mechanism being so proportioned and arranged that said bolt will in erected table position automatically fall into interlocked registry with the link aperture and which lever when actuated serves to disengage the interlocked bolt.

4. In a collapsible table adapted to unfold into erected position, a top board, a front leg portion of which one end is pivoted to the board, a subsidiary pivot disposed between the ends of said front leg portion, a rear leg structure having one end pivoted to the board in spaced relation to the pivotal attachment of the front leg portion, supplemental pivot means disposed between the respective ends of the rear leg structure, brace rod means extending between the subsidiary pivot and the supplemental pivot means, a toggle jointed linkage comprising a pair of links of different lengths with a terminal of one such link pivotally adjoined to a terminal of the other link and which shorter link is apertured intermediate the length thereof, the free terminal of the shorter link being mounted upon the subsidiary pivot and the free terminal of the longer link being pivotally bracketed upon the board contiguous to the attachment of the rear leg structure, and a latch mechanism including a manipulative pry lever together with a resilient strip secured to the subsidiary pivot to constitute an interposed pivotal mounting for said lever and of which lever one end is equipped with a shiftable bolt that in erected table position interlockingly engages the aperture of said short link, said mechanism being so proportioned and arranged that a manipulation of the other lever end inwardly toward and axially crosswise of the erected front leg withdraws the engaged bolt from said link aperture.

- U'DO Ks JOHANNSEN.

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