US2256889A - Folding table leg brace lock - Google Patents

Description

P. BLINK Sept. 23, 1941.

FOLDING TABLE LEG BRACE LOCK Filed Jl me '7, 1940 INVENTOR a2 6% ATTORNEY- Patented Sept. 23, 1941 7 2,256,889 FOLDING TABLE LEG armor LOCK Peter Blink, West Allis, Wis., assignor to Mitchell Manufacturing Company, Milwaukee, Wis., a corporatienof Wisconsin Application June 7, 194.0, Serial No. 339,352

4 Claims.

This invention relates to improvements in folding table leg brace locks.

Collapsible tables, platforms and stands are provided with folding legs and each leg unit is foldably maintained in a perpendicular supporting position by means of pairs of pivotally joined braces or stays whose opposite ends are hingedly connected to an under portion of the table or platform, and to a portion of the leg unit, respectively. The function of a pair of braces is to insure maintenance of an unfolded leg unit in a proper supporting position. However, if the pivotally joined ends of a pair of braces should, under pressure or strain, tend to break or fold in either direction, then the legs associated therewith will be deflected from vertical and the efiicacy of the same for supporting the table or platform will be imperiled and the table may collapse or tilt.

It is, therefore, a primary object of the present invention to provide a folding table leg brace lock, which, when the legs of the table are unfolded to proper supporting position, will automatically lock and hold the outstretched associated braces against undesired movement or folding in either direction and will consequently insure maintenance of the legs in proper, rigid, supporting position.

A further object of the invention is to provide a folding table leg brace lock which will automatically snap into its locking position when the leg unit and associated braces are unfolded to their proper positions.

A further object of the invention is to provide a folding table leg brace lock of the character described which can be actuated, by a simple manual manipulation, to release it for permitting return folding of the leg unit and associated braces to their proper collapsed or folded positions.

A further object of the invention is to provide a folding table leg brace lock of the character described which, when manipulated for releasing purposes, positively prevents folding movement of the braces in an improper direction and requires folding movement of said braces only in the correct direction.

A further object of the invention is to provide a folding table leg brace lock which, when'the leg unit and associated braces are outstretched in proper supporting positions, can be set so as to prevent manipulation for releasing purposes.

A further object of the invention is to provide a folding table leg brace lock which is of very simple construction, is easy to manipulate,

may be applied to a folding table or platform structure with facility and at a minimum of expense, is strong and durable and effective, and is well adapted for the purposes set forth.

With the above and other objects in View the invention consists of the improved folding table leg brace lock, and its parts and combinations as set forth in the claims, and all equivalents there- In the accompanying drawing in which the same reference characters indicate the .same parts in all of the views: W V

Fig. 1 is a fragmentary 'invertedplan view of a table showing a folding leg unit associate-d with one end thereof with folding bracesbetween the under surface of the table and a portion of the leg unit and with the improved brace lock applied adjacent the joint between the connected ends of the braces, the leg unit, and braces being shown incollapsed position;

' Fig. 2 is a fragmentary transverse sectional view through the in'vertedtable top showing a leg unit unfolded toward its perpendicular or supporting position, with the associated braces like-' wise unfolded and in the position the same assume just prior to their final" bracing position and prior to the securing of the brace lock member;

Fig. 3 is a fragmentary detail sectional-view similar to the showing in Fig. 2, only showing the braces in their final outstretched supporting position secured against deflection from this position by the improved brace lock;

Fig. 4 is an enlarged'fragmentary detail view, partly in section, showing the brace lock in locking position, as applied to the unfolded braces of a leg unit;

Fig. 5 isan enlarged fragmentaryview of the brace lock in its released position with the braces I in substantially the condition shown in Fig. 2; and

Fig. 6 is a detail sectional view taken on-line 6-6 of Fig. 4. I

Referring now more particularly to thedraW- ing, it will appear that the numeral l0 .desig nates a flat table top, platform or other structure which is to be supported by folding legs. Folding leg units ofthe type illustrated are'applied to both ends of the table top or platform I 0 and may furthermore be applied to intermediate portions thereof .if the member I0 is unusually elongated. Obviously the legunits and associated mechanism are securedto the under surface of the table or platform l0, and are adapted to be folded flatly against. said surface within the confines of said rails ll when the a le'or oFFIcE i platform is collapsed. In the drawing only one leg unit, applied to a single end of the member ID, has been illustrated, together with the associated braces and brace look, but it should be understood that for the other end of the table or platform, and for intermediate portions thereof, if necessary, said arrangement may be duplicated.

A typical form of leg unit is designated generally by the numeral l2. This unit, at its inner end, includes a pintle rod l3 traversing the under side of the table top If! and having its ends journalled for rotation in suitable bearing brackets I4. Longitudinal elements 15 extend spacedly from intermediate portionsof the pintle rod l3, and at their outer ends said elements [5 merge into an outer transverse member I6 whose extremities I! are turned right-angularly to provide the supporting extremities of the leg unit.

Rigidly extended between intermediate portions of the leg elements 15 is a transverse strut '18 having a curved or bowed medial portion l9. Projected from said'bowed portion IQ of the strut I 8 is aflange 20 to which is pivotally secured, as at new end of a brace 22. The opposite end of the brace 22 substantially overlaps the outer end of a companion brace 23 and the adjacent ends of the braces 22 and 23 are pivotally secured together by a rivet 24. The inner end of the brace 23 is pivotally secured, as at 25, to a lug 26 projecting from a plate 21 secured on the under side of the table top or platform I 9. With the structure thus far described it should be apparent that the leg I2 in its inoperative position assumes the position of Fig. 1 against the inner face of the table top Ill, and the braces 22 and 23 fold upon one another and likewise extend compactly adjacent the inner surface of the table top H]. When it is desired to unfold the leg unit l2 for table or platform supporting purposes the leg unitis moved bodily,- with the pintle ends turning in the bearing brackets M, to move the leg unit from its horizontal position to a projecting position perpendicular to the plane of the member Ill. During this movement the com panion braces 22 and 23 unfold relative to each other and ultimately become extended, as in Figs. 2 and 3, and in their extended condition the same provide a foldable bracing arrangement extended diagonally from an under portion of the table to a leg'unit strut I8. It will furthermore be obvious that without the provision of any stop or limit means the braces might be defiected from their outstretched position andbe caused to break or commence to fold in either direction, To prevent this contingency and to provide a positive automatic means for retaining the braces in their unfolded outstretched and alined condition, thereby assuring rigid securement of the leg unit in its perpendicular supporting condition, the present invention provides an improved brace lock designated generally by the numeral 28.

The brace lock 28 is applied'to the hingedly connected overlapping or knee portion of the companion braces 22 and 23. This lock is in the form o'fa 'curv ed'shell having a transverse dimension slightly greater than the width of the braces'to'which it is applied. Intermediate side portions of the lock shell 29 are pivotally mountedon a pin 36 which is journalled in an enlarged portion of a plate 3| rigidly secured to an outer face of one of the brace members. Within the rear portion of the shell 29, which serves as the handle or grip for operating purposes, and confined between a wall of the shell and a surface portion of the plate 3|, is a coiled spring 32 which serves to normally urge the handle or grip portion of the shell outwardly to project the inner portion of the shell in the opposite direction. The side walls of the shell at its innermost extremity are formed with ears 33 and 34. It will be observed that the ear 34 on the innermost side of the shell 39 is substantially longer than the opposite ear 33.

The general manner in which a leg unit and the associated braces are unfolded and projected has heretofore been explained. When the leg unit and braces are moved from the position of Fig. 1 to the position of Fig. 2 (the latter figure representing the condition of the parts just prior to the final securement of the parts in supporting position) the unfolded braces are not quite longitudinally alined. The short ear 33 of the locking shell 29 rides on the limited exposed adjacent surface of the brace 22. To complete the unfolding operation the associated braces 22 and 23 are moved a trifle further so as to cause perfect longitudinal alinement of the same, Whereupon the short ear 33 of the shell 29 will ride off of the brace 22 and assume the edge-embracing position shown in Fig. 3. The compensating movement of the shell 29 is permitted by virtue of the-pivotal mounting 30 and the expanding action of the spring 32. It will also be noted that the long ear 3 of the shell 29 substantially engages the opposite side edges of the outstretched braces 22 and 23. Hence, in the arrangement of Fig. 3, with the leg unit in its perpendicular and correct supporting position, the outstretched braces 22 and 23 are actually embraced and confined between the ears-33 and '34 of the shell 26. As long as the locking shell is in this position, and it will normally stay in this position'by virtue of the spring 32, the braces are absolutely locked against folding or .defiection movements in either direction, and consequently the leg unit is very effectively and firmly sustained in its perpendicular supporting position.

It may be desirable to secure the locking shell 29 in the effective position of Fig. 3 or Fig. 4 against unauthorized tampering or release, and for this'purpose the grip end of the shell 29 is provided with a tapped opening 35 (see Fig. 4) into which a bolt 36 may be screwed, with the inner end of the bolt impinging against a surface of the brace 23. With the bolt thus positioned it is impossible to manually depress the shell 29 and, hence, the lock 28 cannot be released to disengage the braces, whereby the braces and leg unit may not be unfolded or collapsed. Of course, when the bolt 36 is utilized, which is optional, for ultimate collapse of the table it is only necessary'to unscrew the bolt 36 suificiently to permit manualm'anipulation and depression of the grip end of the shell 29.

It may be additionally explained that by virtue of the extreme length of the ear 34 under no conditions can the shell be manipulated so as to completely disengage the long ear 34 from a' position adjacent an edge of the brace 22. "This long ear 34 therefore provides at all times "a positive limit stop whereby the unfolding movement of the braces is limited. They may not be un-' folded or deflected beyond the outstretched position of Fig. 3. When the leg unit I2 is to be collapsed, however, a depression of the grip end of the shell. 29 removes the short ear 33 from the other side of the brace 22, as in Fig. 2 and Fig. 5, and this will permit a folding of the braces in the proper direction to effect horizontal collapse of the leg unit to the ultimate position of Fig. 1.

From the foregoing description it will be seen that the improved folding table leg brace lock is of very simple construction, automatically snaps into limiting and locking position when the leg braces are unfolded to the correct extent, and is easily manually manipulatable to permit proper collapse of the leg unit and braces when desired. The brace lock is, furthermore, of simple and novel construction and is well adapted for the purposes set forth.

What is claimed as the invention is:

1. A latch for a pair of foldably connected braces pivotally connected at opposite ends with a supporting member and with a leg unit respectively, comprising a shell carried adjacent the mutually joined portions of the braces and operative to embrace said portions of the braces when they are unfolded relative to' each other to prevent undesired folding of the same, said shell including a movable member having opposite side flanges, one of which is substantially longer than the other whereby when the movable member is in one position both of said flanges embrace opposite sides of the mutually joined portions of the braces and prevent movement of the same, and yielding means constantly urging the movable member toward said position, the movable member, when moved away from said position having its shorter flange free of one side of the braces to permit folding of the braces in one direction only.

2. A latch for a jointed and ioldable brace extended between a table top and a folding leg, comprising a shell having transversely separated ears, one of the ears being long and the other being short, means pivotally mounting the shell on said brace adjacent the joint therein, and yielding means constantly urging said shell toward a position wherein both ears abut opposite sides of the brace.

3. A latch for a joint d and foldable brace extended between a table top and afolding leg, comprising a shell having transversely, separated ears, one of the ears being long and the other being short, means pivotally mounting the shell on said brace adjacent the joint therein, and yielding means constantly urging said shell toward a position wherein both ears abut opposite sides of the brace, the shell being manually movable in the other direction to disengage only the short ear from the side of the brace.

4. A latch for a jointed and foldable brace extended between a table top and a folding leg, comprising a shell having transversely separated ears, one of the ears being long and the other being short, means pivotally mounting the shell on said brace adjacent the joint therein, yielding means constantly urging said shell toward a position wherein both ears abut opposite sides of the brace, the shell being limitedly manually movable in the other direction suflicient to disengage only the short ear from its side of the brace, and adjustable and removable means to lock the shell in the first-mentioned position.

PETER BLINK.

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