US2549431A - Retractable worktable - Google Patents

Description

Patent ed Apr. 17, 1951 RETRACTABLE WQRKQTABLE Giacomo Crosa and Luigi Crosa,

Genoa-Bolzaneto, Italy .Application-April20,1948,Serial N0.22, 166 if InItalyApril29y1947,

1 Claim.

The present invention relates to a device for lifting into working position or for lowering into a resting or non-use position, implements, such as sewing machines, typewriters, radiosets, bar equipment and the like;

According to one feature of the present invention, the implement to be placed in diiierent positions is directly or indirectly supported by levers under control of springs which counterbalance the weight and facilitate'the displacement of the implement.

According to a further feature of the invention, one at least of the levers is connected to a movable tube which is subjected, at one end, to the reactionof a loading spring the load of which may be adjusted, the other end of the spring being connected to a fixed point of a cabinet piece of furniture or other support.

According to a still further feature, additional levers cause the regular motion of the implement to be displaced from the position of non-use to that of work and vice versa.

In one of its embodiments, thedevice is characterised in that a. door, lid or the like of the piece ofyfurniture is connected to an actuating lever acting directly or indirectly on the implement to displace it or on a surface which carries the implement.

According to this embodiment, the actuating lever has a movable fulcrum arranged on a small rod rotatable on a pivot fixed to the piece of furniture.

Furthermore, the end of the actuating lever is connected directly or indirectly to the implement to be displaced or to the surface which carries it, by means of a propping rod, this connection being made by at least one universal joint.

In the accompanying drawings, illustrating by way of exam le a, preferred embodiment of the invention, Figures 1 and 2 show mutually perpendicular vertical sections along the planes 1-1 and II-II of Fig. 3 which in turn is a plan view of the device; Fig. A shows, on a larger scale, a section of a detail. of the devicealong the. horizontal plane IV- IV of Fig. 1; Fig. 5 is a plan-view and Fig. 6 a section according to the plane 'VIVI of Fig. 5 respectively of the hinge preferably used.

The piece of furniture consists of two side panels I, .z a-rear panel 3 and the'cover 5, connected by hinge 6 to one of the edges of the top. The typewriter, sewing machine or other im lement. is supported by shelf L-which, when lifted, reaches position 8, At both ends, shelf 1 is connected to arms 9 and I0 which, by means of pivots H and i2, are connected to the pair of arms l3 and i4. Arms M are mounted on pivots E5 in bridge plate 16 fixed to panels I and 2. Arms l3, instead, are connected to a tubular member I! engaged at both ends on cylindrical projections i8 (Fig. 4) of discs I9. The lefthand disc in Figs. 1 and 4 is fixed to the end 2a of a coil spring 2!, the other end of which 22 is fixed to a cylindrical element 23 having a series of radial holes 24 and housed for rotationtherewith in the interior of tube H, which has at least one hole 25 in register-with the holes 24 of element 23, tube l1 and element 23 being locked together by the introduction of a pin or plug in holes 24 and 25.

Under shelf 7 is fixed a propping rod lfi which is connected at its lower end by, bolt 2! to a square member 28 (Fig. 2). Member 28 is part of a hinge 29 to the other side of which is connected one end of a small rod 30, which at the other end, through a hinge 3| is connected to another square member 32 pivotally connected by a pin 33 to the end of a lever 34. This lever 3 1 with'crank 35 is articulated at 36 to one end of a second lever- 31 pivoted at the other end on fixed pin 38 supported by panel I of the cabinet. The other end 39 of crank lever 34 is connected to cover 5. In Figures 1 and 2, the lowered position is shown in full lines with ordinary reference numerals while the raised position is in broken lines with the same numerals primed.

The hinge 6 may have a longitudinal slot 42 traversed by the lever 34, as shown in Figs. 5 andG. 1 The operation of the device is as follows:

According to the weight and volume of the implement placed on shelf 1, a greater or lesser rotation on its axis of tube I! will determine the tension of the spring 2| which will be fixed, by means of a pin going through hole 25 and one of the holes 24, so as to balance almost completely the weight of the movable parts and of the implement placed on the shelf. The rotation of cover 5 in the directionof arrow 4.9 through levers 34, 31, 30 and propping rod 26, will cause the lifting of shelf 1 in the direction of arrow 4! m a pair of parallel motion linkage systems connected to two opposed sides of the member each comprising two vertically spaced parallel links, a vertical movable strap rigidly connected to each said side of the member and pivotally connected to one end of the two links and a second strap pivotally connected to the opposite end of the two links and fixed to a support, a vertical prop rod depending from the underside of the member rigidly connected thereto and having a hinge connection at the lower end, a linkage system including at least one universal joint and comprising a first link connected at its lower end to said hinge connection and situated substantially alongside of said prop rod, an actuating link pivotally connected at one end to said first link and at the other end to a hand actuated member movable between two positive positions of rest, and a fulcrum link pivotally connected at one end to the support and at the other end to an intermediate point of the actuating link, and resilient means yieldably opposing downward movement of the supporting member from raised to lowered position.

GIACOMO CROSA.

LUIGI CROSA.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 969,938 Colegrove Sept. 13, 1910 1,057,809 Diehl Apr. 1, 1913 1,338,834 Kundtz May 4, 1920

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