US2526666A - Adjustable support structure - Google Patents

Description

oct. 24, 1960 `A, L, JOHNSON 2,526,666

ADJUSTABLE SUPPORT STRUCTURE Filed Jan, 11;-1946 2 ShetS'f-Sheet 2 INVENTOR ALV/NL. JOHNSON @www MTORNEYA Patented Oct. A24, 1950 UNITED STATES PATENT y OFFIC ik' l52,526,666 I y l ADJUSTABLE SUPPORT STRUCTURE 'l Y Alvin L. Johnson, Worcesten'l'viass. v,A'pplicatimJarman' 11, 1946, serial No. 646,541

7 Cia'ims. (ol. ca -121) This invention relates to adjustable supports in general and it is the principal object of the in vention to provide a support such as a table, chair, lap board, etc., the height of which is readily adjustable. Y

Several persons of varying heights in a house hold may wishto use the same table, chair, or

ironing board,V or the same person may use the `same at usual height when doing certain things but Will want the table o rboard at a lower level when doing something else. It is an important object of my invention to provide a table, chair, or any board the height of which can be changed easily by the user merely by depressing a convenientpedal or lever.

It is another object of my invention to control the height of a support by a mechanism readily released to permit lowering thereof but so constructed that it Will slip and remain in any desired position when the support is raised.

The present support is carried by two pairs of vlegs one pair of which ispivoted to one end of the support. The other pair of legs is connected to the support by an improved sliding attachment which acts not only to permitr sliding but also frictionally resists too rapid descent ofkv the support When thel pedal is released.

.Itis a more specific object of the invention to vconnect the 'bottoms of the aforesaid twopairs of legs by a friction lockfreleasable by the pedal. Two springs of unequalstrengths vact on the lock, one normally holding it in locking position but being overpoweredby the other springto move lthe lock to unlocked. position vwhen the p e'dal isA It is amore particular part of the invention `to locate the lock and p arts associated in it in a housing which is so located as to engage the pivot of the legs and thus prevent bending of the control and locking rods when the support is collapsed for storage purposes.

, Withthese and other objects in view which .will appear as .the-descriptionproceeds my in -vention residesin` the combination andfarrange- Aof illustration.

Fig. 5 is a plan View looking in the direction' of arrow 5, Fig. 1, parts being broken away;

Fig. 6 is a horizontal section on line 6 6, Figfll,

Fig. '7 is an enlarged vertical section on line 1 1, Fig. 6, i

Fig. 8 is a vertical section on line S-, Fig. '7, Figs. 9 and l0 are diagrammatic side eleva# tions showing the manner of lowering and raising, respectively, the support shown in Fig. 1, and Fig. l1 shows the preferred form of` support collapsed and standing on end for storage poses. u

This invention is usable with any supportssuch as tables, chairs, boards, benches, etc., ofA any nature, but it is disclosed herein as being applied to an ironing board merely for purposes of clarity Referring particularly to Figs. l, 5 and, I have shown the board proper on which ironing opera; tions are performed at I0, a pair of primary` or control legs Il and I2, and a second pair of sece' ondary or sliding legs I3 and I4. A bolt 'Eliserves as a common pivot for the legs and may besurrounded by front and back spacers I6 and I1, and an intermediate spacerjl, seeFig. 5. j' Ahbearing frame 2|] is secured at'ZI to the underside of board jm, see Fig.;4, and has pivoted thereto at ,22 the upper ends of the primary legs. y Extending along the underside of j board l0' i s a guide bar or rail 2.5 spaced below. the bottom of the board by washers or spacers` 26 and held Ato the board by vbolts or the like 21 which .pass

v through the ends of the rail and the washers.

strip 32from the edges of which depend reinforcing ang'es 33. .It is in the llatter that the aforesaid slots: 28 are formed, and these flanges are on opposite sides of a Verticalline Apassing throught alignedpivots 3l. In this way I Vinsure smooth sliding of the cross `bar along the `rail while the bar contacts board i!. The` rail isv prefff erably'rnetallic and is sufficiently resilient to ex upwardly under the Weight ofthe board to effect the aforesaid frictional engagement. i

The mechanism for adjusting the height of the board I0 is shown more particularly in Figs. lj 6, 7 and'8. As shown in Figs. l and ,the bottom 3 ends of the primary legs are connected together by a short bolt 35 from which the legs ll and i2 diverge upwardly toward their pivots 22. A short distance above bolt 35 is a second somewhat longer bolt 36 which serves as a pivot for a pedal 31 and the left end of a bar 38 of channel form, see Fig. 8, and having upturned edges or anges 39. The bar 38 may be made of metal and near that end of it adjacent to the secondary legs has secured thereto a housing 4!! having front and vback vertical walls All and 42 connecting with Laterally eX- right and left end walls vd3 andlll. tending feet 45 on the end walls are secured to the bottom of channel bar 35-at 45. The relation of the housing and bar 3B is shown inFigs. 7 and 8.

As seen in Fig. 6 the secondary legs are connected by a. brace 3 to the center of which is secured an angle bearing 5l. A lock rod 52 hasone end thereof bent and extended through bearing 5|I to have pivotal connection with the latter. Rod 52 extends away from brace 55 and passes through slide bearings or preferably closely tting holes 53 and 54 in the right and left end Walls 43 and M, respectively= and projects some distance to the left of the housing a0, see Figs. 1, 6 and 7.

A second rod 55 is pivoted at to the pedal above pivot bolt 35 and extends to the right and into housing lil), see Figs. 1 and '7, where it is bent laterally to form an eye 57 lying close to end wall 43 and surrounding rod 52. Between the eye 51 and the left end wall lie are three movable members lcomprising a lock plate 55, a relatively strong compression spring @l between eye 5l and plate 60, and a relatively weak spring 52 between the lock plate and the left end wall d5.. A cylindrical stop'63 concentric with the lock rod 52 has a right hand stop surface 64 lying preferably in a plane perpendicular to rod 52 and positioned to engage the lock plate and hold it square across rod 52 when strong spring El is caused to exert considerable force on the lock plate. The latter has a hole 65 therein through which passes lock rod 52 and of a diameter slightly greater than that of rod 52. The lock plate has a broad lower edge Sfor engagement with the bar 38 as shown in Fig. 8, and a stop 61 secured to bar 38 may be used to limit motion of the lock plate E!) to the right, see Fig. 7.

As shown in Figs. 7 and 8, parts of the top E8 of the housing, rear wall 52, and left end wall 44 (Fig. 7) areremoved to provide an opening '69 which permits entry of eye 5'! on the control rod 55 into the housing. Opening 55 also facilitates assembly of the springs and lock plate on the, lock rod 52.if the latter is inserted through the end wall 43` after the vhousing has been secured to the bar 33. The parts in the housing, however, can be assembled as indicated in Fig. '7, after which the housing can be secured to bar 38.

Assuming that the board is in the stable position shown in Fig. 1,.weak spring 52 will be expanded to hold the lock plate 5S in the full line position shown in Fig. .7 in which position the bottom of the lock plate will be against stop 51 and weak spring 52 will hold the lock inclined. When the lock is thus placed the lower left edge of hole 65y frictionally engages the underside of the lock rod 52 and the latter together with bar 38 forms in effect a link of given length and holds thelegs against spreading.

When it is desired to lower the board lt. the

thereby rocking the pedal in a counter-clockwise direction as viewed in Fig. l and moving control rod 55 to the left from the normal to the releasing position thereof. The eye 5l thereupon slides to the left along lock rod 52 and compresses strong spring 6|. thereby overpowering the weak spring and moving the locking plate 5i] to the dotted line position of Fig. 7 against the stop surface 54. The lock rod 52 is now unlocked and can slide through the lock plate, and by holding the left or adjacent end of the board i5 the user can lower the board to the desired level by movement in the direction of arrow a, Fig. 9, after which the pedal is released and the parts return to the locking position shown in Fig. 7, full lines. The board IQ will now remain in its new position shown in dot and dash lines, Fig. 9.

During lowering of the board lil the bar or head 29 will slide frictionally along the rail 25 to resist too rapid a descent of the board if the user should not have a im hold on it. Also, the legs i3 and. i4 slide along the floor and thus supply additional friction resisting downward movement of the board. The latter, however, will ordinarily be heavy enough to move down when the 'pedal is lowered and overcome the frictional resistances mentioned.

When the board is to be raised the userplaces her foot on the bottoms of the control legs near the Ybolt 35, and! then raises the board as indicated by arrow b, to .the dotted position of Fig. l0. During this operation the lock rod slides to the left, Fig. 7, through the lock plate without requiring release ofthe lock.. The. lock plate will prevent reverse motion of the lock rod t0 the left, and the board will remain in its raised position. Raising of the board'may be easiler if the user placesher foot on the lower ends of the control legs and then depresses the pedal, since this procedure will movethe lock plate to unlocking position and the lock rod can slide through it easily.

Fig. 11 shows the board collapsed and standing on end for storage purposes. When the board is to be put away the pedal will be depressed until theboard falls to a position close to the floor, after which it can be Vstood on end as shown in Fig. l1. In the collapsedposition the housing engages the pivot bolt I5 and thus prevents bending of the control and lock rods if excessive'pressure should be accidentally exerted on the board. The lock rod islong enough to permit this collapsing. Y

From the foregoing it willbe seen that I have provided an ironing board with pairs of legs pivoted together andoonnected in pairs by a link Variable as to vlength for the purpose of adjusting the height of the board. The. link extends between the lower ends of the legs and preferably does not project beyond them, hence there is no danger that the user willtrip over it, or the pedal hy which the lock is released. The board can be folded and stored as suggested in Fig. 1l.. When the board is folded the housing will prevent the -pivot boltv I5 from engaging'and bending the con- Having thus described my invention it Will be' seen that changes and modications may.v be made therein by those skilled in the art without departing from the spirit and scope of the invention and I do not wish to be limited to the details herein disclosed. but what I claim is:

. 1. Adjustable supporting .means comprising, crossed pairs of legs pivoted together two members slidable relatively to each other and located below the point of crossing of said pairs of legs,

one member operatively connected to one of said pairs of legs and the other member operatively connected to the other pair of legs, lock means normally locking said members together to prevent separation of the lower ends of said pairs of legs, a pedal pivotally mounted with respect to one of said pairs of legs, and connections between said pedal and lock means eifective when the pedal is depressed to move said lock to abnormal position to unlock said members and permit relative sliding movement of the latter. in a direc-l f tion corresponding to separation of the lower ends of said pairs of legs.

2. Adjustable supporting means for a board or the like, cross pairs of legs pivoted together and supporting the board at their upper ends, the board due to the weight thereof tending to separate the lower ends of said pairs of legs,'a lock rod member operatively connected to the lower end of one of said pairs of legs, a holding bar member operatively connected to the lower ends of the other pair of legs and having a sliding connection with the lock rod member,'a lock mounted on one of said members normally locking said member against motion in a direction corresponding to separation of the lower ends of said pairs of legs, .a pedal movably supported by the lower ends of one of said pairs of legs, and a control rod connected to said pedal and guided and supported by one of said members and effective when the pedal is depressed to cause said lock to unlock said lock rod, whereupon said lock rod is capable of sliding movement with respect to said housing means in a direction corresponding to separation of the lower ends of said pairsof legs.

3. In adjustable supporting means for a member, cross pairs of legs pivoted together and supporting the member at their upper ends, the' member due to the weight thereof tending kto separate the lower ends of said pairs of legs, a holdingbar, a pivotal-connection between said bar and the lower ends of one of said pairs of legs, a pedal pivotally mounted on said pivotal connection, a lock rod operatively' connected to the lower ends of the other pair of legs, lock means normally in position to lock the holding bar and lockVV rod together to prevent relative movement thereof in a direction corresponding to separation of the lower ends of the pairs of legs, and a control rod for the lock operatively kconnected to the pedal and effectivewhen the latter is depressed to cause said lock to move to unlocked position, thereby enabling the lock rod to move relatively to the holding bar in a direction corresponding Vto separation of the lower ends of said pairs of legs.

4. Adjustable supporting means comprising, crossed pairsof legs pivoted together two members slidably connected to each other andlocated below the point of crossing-of said pairs of legs, one member operatively connected to one of said pairs of legs and the other member operatively connected to the other pair of legs, adjacent ends of said members mutually supporting each other, lockA means operatively secured to one member for engagement with the other member, resilient means normally holding the lock means in position to lock the members together to prevent separation of the lower ends of said pairs of legs, and pedal means held in normal position by said resilient means and operative when moved to releasing position to move said lock means against the action of said resilient means to abnormal position to unlock said members, the latter thereupon being capable of relative sliding movement to permit separation of the lower ends of said pairs of legs, the resilient means returning the lock means to normal position to lock said members together upon movement of the pedal means to the normal position thereof.

5. In adjustable supporting means for a member, crossed pairs of legs pivoted together and supporting the member at their upper ends, the member due tothe weight thereof tending to separate the lower ends of said pairs of legs, holding bar means operatively connectedto the lower vends of one of said pairs of legs, a lock rod operatively connected to the lower ends of the other pair of legs and having sliding relation with respect to the holding bar means, a lock operatively secured to said holding bar means surrounding the lock rod, a spring normally holding the lock in locked relation with respect to the lock rod, a second spring stronger than the rst named spring normally ineffective to move the lock to unlocked position, and pedal operated control means extending into operative relationship with respect to said second spring and effective when moved in a given direction to cause said second spring to overpower the first named spring and move the lock to unlocked relation with respect to said lock rod, whereupon said lock rod is capable of movement relatively to the holding bar means in a direction corresponding to separation of the lower ends of said pairs of legs.

6. A continuously adjustable supporting device comprising crossed pairs of legs pivoted together,a

. rod connected to each of said leg pairs, a tilting fric vent relative separating motion thereof so that the leg pairs cannot separate, said lock means being eiTective to provide for easy, smooth, and continuous relative advance of the rods to allow the leg pairs to move toward each other, and means to release the lock means.

7. A continuously adjustable supporting device comprising crossed pairs of legs pivoted together, a rod connected to each of said leg pairs, a lock means on the rods and being effective normally to prevent relative separating motion thereof s0 that the leg pairs cannot separate, said lock means being effective to provide for easy, smooth and continuous relative advance of the rods to allow the leg pairs to move toward each othenmeans to release the lock means, means to normally urge the lock means to locking position, a control .means to operate the lock release means remotely from the lock means, one of the rods Vbeing a lock rod and the lock means compris- (References on following page) REFERENCES CITED UNTTED STATES PATENTS Number Name Date Kilbourne Mar. 4, 1879 King June 27, 1882 Parmelee July 19, 1892 Finnegan et a1 Apr. 3, 1900 10 Number 8 Name Date Messer N'ov. 14, 1905 Thorner Oct. 11, 1910 Hone Dec. 7, 1915 Danielson Mar. 30, 1920 Stevenson May 17, 1932 Swanson July 26, 1932 Williams May 8, 1934 Johannsen Aug. 31, 1937 Monnot Feb. 8, 1944

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