US2672387A - Folding table leg and locking mechanism therefor - Google Patents

Description

March 16, 1954 FLDING TABLE LEG AND LOCKING MECHANISM THEREFOR A. G. BARRlcKs 2 Sheets-Sheet l .March 16 1954 A. G. BARRlcKs 2,672,387

FOLDING TABLE LEG AND LOCKING MECHANISM THEREF'OR Filed 0G12. 5l, 1950 2 Sheets-Sheet 2 INVENTOR. m m'c/af. 24 26,26 27 BY Patented Mar. 16, 1954 FOLDING TABLE LEG AND LOCKING MECHANISM THEREFOR Arthur G. Barricks, Chicago, Ill.

Application lOctober 31, 1950, Serial No. 193,262

Claims.

My present invention relates, generally, to innovations and improvements in folding table legs and locking mechanisms therefor which are stronger, more rigid, longer wearing, and safer than previous folding table leg and 1ocking mechanism units of which I am aware, as well as being more economical to maintain and more convenient to operate.

While my present invention is applicable, generally, to folding or collapsible tables of all types, it is particularly suited for large, heavy-duty tables of considerable weight and length such as are used in hotel, restaurant and institution dining rooms. Such tables are subjected to rough handling and usage and are required to sustain heavy loads.

An important object of my invention is a new and improved folding table leg and locking mechanism unit for use with a table top, or the like, and characterized by: its superior strength and rigidity; the positive and safe action of the locking mechanism; absence of free play or looseness between moving parts; ease with which the folding leg mechanism may be operated both to fold and unfold the legs; simplicity and ruggedness of design; and, ability to withstand rough usage and wear for long periods of time without developing looseness or mechanical difficulty.

A more specific object of the invention is a folding table leg unit and locking mechanism therefor for collapsible type tables, or the like, wherein a rail constitutes one of the elements thereof and is adapted to be attached to the bottom side of a table top so as to also serve as a rigidifying member or brace for the table top.

Another object of the invention is a folding table leg unit and locking mechanism therefor wherein the locking mechanism automatically compensates for wear of the moving parts so as to prevent looseness or free play from developing.

Still another important object of the invention is a folding table leg and locking mechanism unit adapted to be easily attached to all types of table tops and other flat platforms.

Certain further objects of the invention will, in part, be obvious and will, in part, appear hereinafter.

For a more complete understanding of the nature and scope of the invention, reference may now be had to the following detailed description thereof taken in connection with the accompanying drawings, wherein:

Fig. 1 is a perspective view showing a folding type table in theerected or unfolded condition,

and which is provided with a pair of folding table leg mechanisms forming one embodiment of the invention;

Fig. 2 is a bottom plan view showing the underside of the table shown in Fig. 1 with one of the pairs of legs being shown in its folded condition and the other pair being shown in its unfolded or extended position, the latter pair of legs being also shown in the folded condition in broken line;

Fig. 3 is a side elevational view of the table of Fig. 1 with the opposite pairs of legs in the collapsed and folded condition;

Fig. 4 is an enlarged fragmentary sectional view taken on line 4 4 of Fig. 2;

Fig. 5 is a View corresponding to Fig. 4 but with the pair of table supporting legs shown locked in the unfolded vertical position;

Fig. 6 is a fragmentary perspective View taken on enlarged scale showing one of the leg locking units as it appears in Fig. 2;

Fig. '7 is a detail sectional view taken on line 1 1 of Fig. 5;

Fig. 8 is a detail sectional view taken on line 8 8 of Fig. 4;

Fig. 9 is a perspective View of a clip forming a part of the folding table leg mechanism; and

Fig. 10 is a side elevational View of a spring loaded finger which forms an element of the leg locking unit shown in Fig. 6.

In the drawings, a collapsible or foldable type table provided with a folding table leg mechanism forming one embodiment of the invention is indicated generally at 5. The table 5 includes a table top 6 which is rectangular in outline and the details of construction of which do not constitute a part of the present invention. The size and shape of the table top 6 may be other than that shown in the drawings and the invention is broadly useful in connection with table tops and platforms of any particular size, shape, or construction.

The table 5 is provided adjacent the opposite ends with two pairs of folding legs which are designated at 1 1 and 8 8 respectively. Preferably, the legs are in the form of integral U- shaped members having straight interconnecting yoke portions l0 and I l, respectively, as shown, for example, in Fig. 2. Pairs of attaching clips or straps l2 l2 and I 3 I 3, respectively, serve to pivotally attach the legs to the underside of the table top 6. The integral U-shaped members providing the legs 1 and 8 may be formed of tubular metal stock. In order to retain the legs 'l and 8 in their folded or collapsed condition underneath the table top 6, spring clips l5 and I6, respectively, are provided. The clips I5 and I5 may be attached to cross bars II and I8, respectively, which form part of the structure of the table top 6. Similarly, the attaching clips or straps I2 and I3 may be attached to cross members or cleats 2U and 2 I, respectively, located at opposite ends of the table top and forming part of the structure .thereof An important part of the 'j folding table. leg mechanism is the rail means, indicated generally at 22 in Fig. 2, which extends lengthwise of the underside of the table top 6 and is equally spaced between the opposite sides thereof. v4-Therail means 22 comprises a pair of angleY iron-bars 23-23 which are attached to thefunderside of the table top 8 by means of a series of spaced apart spacer blocks 2li-2d. "The=blocks`24 may take the form of wooden pieces Whichare. secured to the under structure or cross members of the table top Eby means of wood screws 25-25, the heads of which are countersunk and iiush with the bottom faces of the blocks 24. rThe angle iron bars 23 are.. attached. to oppositesidesof the spacer blocks'2ll .with the vertical legs 2'3-26 (Fig) of the bars23 attached to opposite sides ofthe spacerblocks. and with the edges of the legs 25`1ittingagainst the', cross bars or cleats of the vvtable topiE. 'The horizontal legs 2'I-2'! of the, angleironhars are` outwardly/directed in oppositedirection asshown; for example, in Figs. 6 and 8. ScreWs28-'28.serve to secure the vertical legs 26 to the opposite sides of the blocks 2e.

In addition' tom functioning .as aA rail means as will be explained indetail below, the rail means 22 also serves. asa longitudinalv rigidifying or strength impartingmember'foithe table top 5. If desired, the rail means'22may be divided into two,sections,.one for each end of the table or other platform.

So-called rail followers vform part of themechanism associated with each of the pair of folding legs 1 and.8. The railfollowers` may take 'the ormofstuds or"bars`3"and 3I whichmay be formed of cylindrical rod stock. These elements have ksuiiicientl length'soas toproject overv the opposite edges-of thex horizontal legs`-27 ofthe rail means 22 when the vfollowers are placed crosswise thereof'as shown,'for-example, in Figs. 2 and 8. The bars 3D and'- 3 I-may`be tapped from opposite ends soas to Iprovidefor the reception of screws 32'32-which serve 15o-connect the adjacentk ends of leg-brace links- 33 and 3e to the followers and* 3 I respectively.

The links 33 have end portions 35-35 by which the links can be pivotally attached tothe legs 'I by'means of rivetsSG-#SE- extending therethrough as indicated in-iFigs. 1 and 2. Similarly, each of the links34 has an end'por'tion 3l on oneend thereof |luy which' the-linkmay be pivotally attached by a rivet-38 ,tof one ofthe legs 8 intermediate the ends thereof.

lEach of thelbrace'l links' 33 also has an end portion -40 on the opposite end from the end portion whichextends parallel to the length of; the vtable 5 andalso parallel to the end'portionsv 35. These'end portions 43 are secured to theadjacent endsof the rail follower 3E by means ofthe-screwsv32. In lkevmanner, each of the brace links 34- is provided with end portions 4I which are attached by screws i2-'42 to the adjacent ends of 'the rail follower 3i.

*The rail followers-'30 and 3I-aremaintained atall times in sliding contactwith the ,underside of the'railsor'horizontal legportions ZIbymeans of lLJshaped elipse' 43 Awhich are shown' in detail lili topsidesof.thehorizontal railnleg 2.1,.as shown.

Only oneuof the-clips 31 is required'for. each of the followers 33 and 3l.

When the pairs of legs I and 8 are in the folded or collapsed position and fitting against the'f-undersideofl the table top ii, the followers 30 and-`3|-are in positions adjacent the middle l5 ofi-the table. When the legs l and 3 are vertically extended or turned downwardly, the folrlowersl 3I) and 3l fare retracted along the rail means22to positions closer to the respective ends of the' table top 5. Thus, in Fig. 2 of the drawings, the follower 33 is'shown in broken line in its' position adjacent the center of the -tablewith the legs 'I folded underneath the table topA 5 and in fullline the legsl are shown in theirdownwardly turned or vertical position with the follower 30 in 'its retracted positions.

Locking units are associated with each of the pairs' of legs l and 8- to firmly securev and lock the legs when they are in their downwardly turned, table-Supporting position. These locking units cooperate with the rail followers 3!) and 3I and are indicated generally at'65.

Each of the locking mechanisms I5l includes a spring loaded ngeror trigger d5 formed of a suitabler material such as steel or aluminuml and provided with a pin receivingaperture' 41; a locking notch 48 and a safety notch 50. vThe trigger d6 is pivoted intermediate its ends on a pin 5I which projects through the aperture el and* which is supported on opposite rends in left-handed and right-handed Ifixtures 52 and'53. The fixtures 52 and 53 have horizontal iiangesby which they may bev attached to the horizontal legs'Z'I'y of the angle iron bars 23 by'means of bolts 5d-54- 'The vertical portionsl 55and'56 of the fixtures 52 and 53, respectively, arel provided with aligned apertures which receive the opposite ends of the pin 5I so that the trigger ll'islocated midway therebetween.

A coil or torsion type spring is provided for each trigger so as to force the end thereof provided with notches 48 and 56 toward the table top. The spring is designated generally at 5'! .in Fig. 6 and is formed of spring wire stock and'has an outwardly extending middleportion' 58 which 5 iits over the trigger 46 adjacent;V the endY thereof opposite the notches i8 and 50. The end engaged by the spring portion 58 is designated-at 66] and may be termed the iinger portion of the trigger 46 since it is the portion which the table user touches to operate the trigger when the table 5 is to be collapsed. The spring 51 also includes coil portions 6 I-'SI which iit over and around the pin 5I and in between the upright portions 55 and 560i the fixtures 52 and 53, respectively, and the adjacent side of the trigger 46 as shown in Fig. 6.

The inner end ofeach of the coil portions' EI extends outwardly and is connected integrally with the portion 58 which engages the trigger 4E as described above. The outer end of. each of the coil portions 6I is formed into a free end portion G2 (Figs. 4 and 5) theends 830i Vwhiclfriit behind one of the cross pieces orA cleatspf. the table top 6. l

Since the. freeends 52-1-E2garean'chored against rigid portions ofthe table top structure and are not free to move, the portion 58 which engages the end 6l) of the trigger 46 tends to rotate the trigger 4G about the pivot pin 5| in such a way that the end carrying the notches 48 and 5t is forced towards the table top, that is, in a counterclockwise direction as viewed in Figs. 4 and 5. The outer end of the trigger t6 adjacent the safety notch E@ has a curved or camined contour as indicated at 64 and the end of this cam portion which is indicated at 65 in Fig. 10 engages the head of one of the screws for a spacer block 24 as shown in Figs. 4 and 6. This is a desirable feature since if the end 65 engaged directly upon the wood face of a sp-acer block 2li, it would very quickly wear a depression in the wood so as to a1- low the end @E to project beyond the faces of the outwardly turned legs Z'I-Z'l and prevent the followers til and 3| from properly engaging with the cam surface S4 so as to automatically force themselves between the trigger 45 and the rails when the legs are unfolded.

The table leg folding mechanisms operate in a positive manner which is apparent from the foregoing description. When the legs are in the folded position, up against the underside of the table top 6, they are retained in this position by the spring clips l5 and I 6. In order to set up the table 5, each pair of legs 'l and ci is freed from the retaining clips |5 and Ie, respectively, and, turned outwardly as far as possible whereupon the rail followers 3h and 3| become engaged in the locking slots or notches 48 of the locking mechanisms IE5. The parts are so dimensioned and arranged that the followers will be so engaged in the notches te when the legs are in the vertically extended position as shown in Fig. l. During the outward turning of the legs, the followers 33 and 3l are retracted along the rails and they reach the place where they engage the cammed shaped ends Ell of the triggers Mi. Continued turning of the legs causes the followers to wedge themselves under the triggers and rst to engage in the safety notch 5G and then on continued movement to the full vertical position the followers are brought into the slots 48.

The purpose of the safety slots 5@ is to insure that the legs will not collapse even through the table is not properly set up by reason of the legs not being extended to the true vertical position.

For example, if someone fails to turn out the legs t far enough, the rail followers 3@ or 3| will not become fully engaged in the respective notches t3 but they will catch in the safety notches 5i). If it were not for the safety notches 59, the table might collapse when a load was placed on it if it were not properly set up. Due to the presence of the safety notches 5E, the legs will not in such an instance collapse .but will be held in a semiupright position until someone comes along' and straightcns them out so that the followers Bil or 3| are brought into the locking notches 48.

In order to fold or collapse one of the tables l after it has been erected, the user in turn presses on the free end 58 of each of the triggers 'St so as to free the notch t8 from the railv follower Sii or 3| and permit the respective pairs of legs 'l and 3 to be folded.

The various parts of the leg folding mechanism should be accurately manufactured and assembled so as to provide a rigid construction which is free from looseness. This is important since if there is excessive free play or looseness, the wear on the parts is much more rapid than if the parts t tightly without looseness or free play. In this connection, each notch 48 in a member 46 is preferably formed so that the front edge of it which is designated at 66 and which engages the respective cam followers 30 and 3|, will tend to seat itself or lock the cam followers with increasing tightness after the followers have once entered the notch 48. The side 66 of'each locking notch 48 is straight and tangent to the curvature at the base of the notch. The surface or edge 66 can stand considerable wear and there will still be a tight locking it against the rail followers 30 or 3| thereby preventing any looseness or shakiness in the legs 'i and 8.

In view of the foregoing disclosure, it will be apparent to those skilled in the art wherein modications may be made in the design of various elements and parts of the folding leg locking mechanism without departing from the spirit and scope of the invention. Accordingly, it is intended that all matter described above or shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense in so far as details of design are concerned.

Having fully described my invention and a preferred embodiment thereof, what is claimed as new 1s:

1. For combination with a table top or the like, a folding table leg and locking mechanism unit comprising, at least one pair of supporting legs, means for pivotally attaching each of said legs adjacent its upper end to a table top whereby each leg is foldable underneath said table top and is downwardly swingable to a vertical table supporting position, said legs being swingable in parallel planes, rail means mounted underneath said table top so as to extend parallel to and be spaced between said legs when the latter are attached to and folded underneath a table top, said rail means comprising a pair of spaced angle iron bars having their vertical legs turned towards the underside of a table top and having their horizontal legs turned outwardly in opposite directions, a plurality of spacer blocks fitting in between said vertical legs in spaced relationship therealong, means for attaching said blocks to the table top, and means for attaching said vertical legs to the opposite sides of said blocks for supporting said angle iron bars on the underside of said table top, rail follower means in the form of a rod extending across the opposite edges of said outwardly turned horizontal legs of said angle iron bars and at least one clip member mounted on said rod adjacent one end thereof with an integral portion fitting against the top side of the horizontal leg of the adjacent angle iron member, a brace link for each of said legs pivotally connected thereto at one end of the link at a point intermediate the opposite ends of the leg with the other end of the brace link being pivotally connected to the adjacent end of said rail follower, and manually releasable locking means for locking each pair of said legs in their downwardly turned table supporting position comprising, a spring loaded trigger having a notch formed in the upper edge thereof for engaging said rail follower, a pin extending from opposite sides of said trigger rearwardly of said notch, fixtures attached to the underside of said rail means for supporting said pin crosswise of said rail means, and a spring one end of which engages said trigger rearwardly of said pin with the other end of the spring engaging a rigid portion of the structure, said spring being maintained under compression so as to press upwardly the forward portion of said trigger having the notch.

7 2. 'I'he -folding leg nand lockingmechanisnx-:unit called .for claim. 1-: wherein. the. trigger7 ofsaid locking means has two. ,notches formedttherein the. rear one of .said notches. serving toengage .and retain said rail. follower whensaidl legs are vertically extended` Vand the front one .ofsaid notches. serving. as a safety notch to engage and retainsaid rail followervwhen the legs have not been fully extended to the vertical position.

3.The folding table .leg mechanism of. claim 1 wherein said spacer blocksl are. attachedto the underside of said table top by screws .the headsof which are flush withwthe bottom faces of .said blocks .a-ndone of saidspacer blocks-isfsolocated withV respectstosaid spring loaded4 finger that the front end of` saidnger engages a screw head in the .bottom yface of saidone spacer block when said` rail follower is not engaged in. said notch ofthe spring linger, the front end of said spring finger .having .a cammed shape so as to permit the rail follower to .force its entry between. the spring finger and the table topagainst the force of said spring.

.4.1 In combination vwith a table. top,.afolding table leg mechanism comprising, two pair of supporting legs located at opposite endsof the Atable top, each of said pairs of legs being Y-provided by an-.integral U -shapedmemben means for pivotally,attaching the yokeportion of each of said U- shaped members to the underside of -said table topwherebyzeachpair of legs is foldable toward each. othery underneath said table top and .each is downwardlyswingable toa vertical table supporting position, rail means mounted underneath saidtable top and. extending parallel yto and spacedmidway betweensaid pairs of legs when the -latterare folded underneath said table top, said .railmeans comprising a pair of spaced angle iron -bars .having their vertical. legs turned towards the underside of said table top and having` .their horizontal `legs turned outwardly, a pluralityvof spacer blocks `fitting infbetween said vertcallegsin spaced relationship therealong, means for .attaching each of saidA blocks yto .the table top. and means. for attaching said verticalflegs of .the angle ironbars to the .opposite-sides .of said .blocks thereby supporting said barsjon the undersideof said table top, rail'follower means for each of said pairs of-legs in theV form of a cylindrical rod extending across theopposite edges of said outwardlyr turnedhorizontal'` legs of Said angle iron .bars and at least one clipmember for each cylindrical. rod havingA loop portion fitting-over the rod adjacent one end thereofwith outwardly turned ends fitting.. against the upper side` of the horizontal leg ofltheadjacentangle iron` ban-.a brace linkr .for each. of saidlegs pivotally connectedthereto at one end of the link at a point intermediate the oppositeends ofthe associated` leg. with .the other endof. the brace link being pivotally .connected .to .the adjacent end ofV the. associated rail follower, .and .manually releasable. locking means for eachof said pairs of legs rfor locking, the, .legsin their downwardly turned tablesupporting position, each ofsaid locking means.` comprising, va spring .loadedngermember having, a notch formedin the upper edge thereof for engagingsaidrail follower, a pinextending from opposite sidesof said linger 8 rearwardly: fof said.- notch,` .fixtures 1- attached-.to the ,underside of saidv rail 'means for supporting said pin crosswise of said railmeans, and a spring oneend of which engages said `finger rearwardly of said pinwith the other end of thespringengaging a rigid portion of the table top structure, said spring being maintained under compression soas to press `upwardly the forwardportionof said finger having the notch.

. 5. For combination with a table top-or thelike, afolding table leg-and locking mechanism-.unit comprising, atleast one pairof table supporting legs, means for pivotally attaching said-legs .adjacent their upper ends to a table top fwhereby the legs are foldablefunderneath said tabletop and arevdownwardly swingable to a vertical table supporting` position, rail means mounted underneath said table top so as to extendparallel. to said legs and spaced therebetween, said railmeans having a pair of horizontal rail anges which are spaced from the bottom surface of lthe table topby meansof integrally formed verticallflanges which are uniformly spaced fromY eachother. so as Ato form a channel therebetween, .means for securing said rail means to the underside of. said table top, rail follower means in .the foi-mona rod extending across. the underside of .-saidhorizontal rail anges and provided withv at least-one hook means which hooks slidably overone of .the edges of said rail flanges so as to retain .therail follower means in sliding contact therewith,.a brace linkage for. each of said pairsof legs. one end of which linkage is pivotallyconnectedto the legs intermediate the endsthereof and the other end of which linkageispivotally connected to the adjacent rail follower rod, and manually releasable locking means for locking each` pair. of said legs in their downwardly turned .table supportingv position comprising, a spring loadedtrigger having a notch formed in thev upperedge thereof vfor engaging said rail follower, aA pin. .eX- tending from opposite sides of said trigger rearwardly of said notch, fixtures attached to the underside of said rail means for supportingsaid pin crosswise of said rail means, andan actuating spring for said trigger one portionof which engages said trigger and another portion offwhich engages a rigid portion of the. structure, said spring being maintained undercompressionso as to press upwardly the forward portion of. said trigger having the notch.

ARTHUR G. BARRICKS.

References Cited' in the le of this patent UNITED STATES PATENTS Number Name Date 390,173 Jones Sept.25, 1888 1,571,807 Schmitt Feb. .2, 1926 1,786,045 Vogt Dec..23, 1930 1,888,117 Fox Nov..151932 1,956,946 Duffy Mayl, 1934 2,223,618 Kalisz Dec. 31940 2,484,768 Van Pelt Oct. 11,1949 I 2,495,965 vGustaveson J an.. 31, 1.950

FOREIGN PATENTS Number Country lDate 6,779 Great Britain 1914

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