US2678859A - Vertically adjustable pedestal structure for drawing tables - Google Patents

Description

May 18, 1954 G. ZUZZl 2,673,359 VERTICALLY ADJUSTABLE PEDESTAL STRUCTURE FOR DRAWING TABLES Filed April 25. 1952 IN V EN TOR. 6/0V4n M/ Z 0:.

springs and/or counterweights. were usually handorfoot-operated. It was also proposed before to equip such (drawing tables with hydraulic lifting devices which, however, likewise required manual operation.

Patented May 18, 1954 NI .STATES PATENT "ICE v Io L Y ADJUSTABLE PEDESTAL STRUCTURE FOR DRAWING TABLES vGiovanni Zuzzi, -Milan, Italy Application April 23, 1952, Serial 'N0. 2 8 3,907

The invention relates tola pedestal structure Itwas proposed before to make drawing tables whichwere equipped with means for lifting and lowering, respectively, the tableand also with means for adjustmentof the table at difierent angles, which means included traction ortorsion These means The provisionof springs and/or counterweights .brought aboutanumberof drawbacks and. among them the necessitylof providing a-cornparatively large space for th operativeelements, the necessity of diificultlabor particularly for heavier tables, interruption of the work by the draftsman for time-.consumingadjustment of theltable,

. and alsowear of the springs and beams required for the properioperation of theadjustment device. In case a hydraulic lifting device isprovided, all drawbacks inherent insuch devices, as

loss or freezin of the hydraulic fluid or other causes for inoperativenessare apparent. If the tabl has to be reset in accordancewiththepre- .vailing light conditions, the entire table, which is inmost cases rather heavy, requires displacement to the bestiightconditions', particularly if the table is to be-shifted'from daylight to arti- .ficial light.

It is, therefore, one object of the present invention to provide .a pedestal structure which .avoids all thementioned-drawbacks, is of simple,

economicalstructure, and permitsof easy opera.-

tion without any physical eifort.

It is another object of the present invention to provide" a pedestal structure which permits of easy lifting and lowering, respectively, thereof,

as well as rotation of the board for 360.

It is :still a further object of the present invention to provide a pedestal structure which Fig. 4 is a fragmentary rear view of the drive .means;and

Fig. 5 is a fragmentary elevational view of the coupling means.

Referring now to th drawing, the pedestal structure comprises-preferably atripod I which carries a platform Zto which a horizontally disposed bevelled gear .3 is permanently secured.

A vertical pin t extends centrally throughthe platform 2, which pin l secures a frame 5 rotatably to the platform 2, so that the frame 5 may rotate for anangle of 360 relativeto the tripod Ball bearings (not shown) maybeprovided between the frame'5 and the platform 2 in order to reduce the friction during the relativerota'ting movement.

A lower housing 6 is secured to and disposed on top of the frame 5 and an upper housing L'l'is telescopically disposed over thelower housing 6. At least two columns 8 extend 'upwardlyin'the lower housing 5, which columns 8 aresecured to the bottom and top platesz9 and I0.

A spindle l l isrotatablymounted in the frame 5 and carries thread 12 on the greater part ofits the spindle II permitsof free rotationand prevents any axial movement thereof. The spindle ll extends into a second hollow spindle l4 having inner thread [5 which spindle I l is adapted to be raised and lowered respectively upon turning the spindle l l in one. or the other direction. A cross'plate It is secured to the lower end of the spindle Hi and the cross plate It has oppositely disposed guides I! which slide on the columns 8 during the lifting and loweringmovement, respectively, of the spindle [4. The top plate Ill has secured thereto another guide member 18 through whichthe spindle M slides during its axial movement. Finally, special guide elements It are'disposed between the outer housing and the lower .housingfi in order to permit easy telescopic movementbetween the said two housings fi and The lower end of the upper housing '1 is necessarily open in order to receive the lower housing 6, while its upper end is closed up'by a plateiiil which is adapted to carry a bracket 2! to receive a horizontally disposed pivot 22. In the application of the structure to a drawing board, a supporting frame 23 is carried by the pivot 22 'by means of a clamping device 24 which maintains the supporting fram 23 in any angular position by means of a screw bolt 25. A lever 26 having a handle 21 is secured to the clamping device and extends in downward direction in order to permit of easy manual adjustment of the desired angular position for theboard 28.

An electric motor 29 is properly supported on the p1atform' 2 ofthe tripod Land the electric m0- tor 29 drives over a belt drive 30 a horizontally disposed main shaft 3!. Two bevelled gears 32 are rotatably mounted, oppositely disposed from each other, on the main shaft 35, and both gears 32 permanently mesh a third horizontally disposed bevelled gear 33 which is keyed to the lower end of the spindle H. A clutch means, preferably a claw clutch 34, is keyed to the shaft 3! and adapted to be moved in axial direction either to the right or to the left in order to couple one of the bevelled gears 32. Thus, depending upon the bevelled gear 32 which joins the rotation of the shaft 3|, due to the particular position of the clutch 34, the spindle ll will be rotated in one or the other direction and bring about the lifting and lowering, respectively, of the column .14 and thereby of the drawing board 23.

The clutch 34 may be operated by a foot pedal 35 or by any other suitable means. If the clutch 34 is in neutral position, the electric motor 29 may be put into operation by means of a switch (not shown) and upon setting the clutch 34 only is it possible to start the lifting or lowering movement of the drawing board 28. Instead of providing inner thread in the spindle M substantially throughout its entire length, a box 3% having inner thread may be disposed at the lower end of the spindle M to bring about its lifting and lowering movement, respectively.

. Relays 3! and 32 are disposed at the bottom 'and near the top of the upper housing I, in order to open the motor circuit when the upper housing reaches the lowermost and uppermost position, respectively. In order to bring about the rotating movemen of the drawing table, the shaft 3i carries a gear 39, and a further shaft 40 is mounted in a cham ber 4| covering the electric motor 29 with its drive. A gear 42 is keyed to the shaft 40 and a pinion 43 is also keyed to the shaft 40 which meshes the bevelled gear 3 of the platform 2. A coupling device, preferably operated by a pedal 44, is also secured to the chamber 4|, which coupling device comprises a shaft 45 the ends of which carry epicycloidal gears 46 and 47, respec tively. Depending upon the position of the coupling device and its pedal 44, the gear 39 meshes the epicycloidal gear 46 and the gear 42 the epicycloidal gear 47 in the coupling position of the device (shown in full lines in Fig. 3), or these gears 39 and 152 are out of mesh in the noncoupling position of the device (shown in dotted lines in Fig. 3). If they are in the meshing operative position, the pinion 43 will turn and rotate along the bevelled gear 3 and thereby turn the entire structure including the housings and i for any required angle to 380 on the pivot 4.

While I have disclosed one embodiment of the present invention, it is to be understood that this embodiment is given by example only and not in a limiting sense, the scope of the invention being determined by the objects and the claims.

I claim:

1. A pedestal structure comprising a base, a first housing rotatably mounted on the said base, a second housing secured in superposed position to the said first housing and. a third housing having a top plate, being open at its bottom and telescopically receiving the said second housing, a motor supported by the said base, gear means driven by the said motor disposed in the said first housing, a threaded spindle extending up wardly from the said first housing into the said second housing, the said threaded spindle being mounted in the said second housing for rotation upon its longitudinal axis, the said gear means including means for driving the said threaded spindle in either direction, a hollow spindle secured in the said top plate of the third housing, the said hollow spindle having inner thread and receiving the said threaded spindle, means disposed in the said second housing to guide the said hollow spindle in axial direction and to pre vent rotation thereof upon turning the said threaded spindle, additional gear means disposed in the said first housing and operated by the said motor for turning the said first housing upon its vertical axis on the said base, and means for controlling the said additional gear means, and the said top plate of the third housing having supporting means adapted to support a drawing board or the like.'

2. The structure, as set forth in claim 1, which includes relay means disposed adjacent the lower and upper ends of the said third housing in order to open the motor circuit upon reachingthe lowermost and uppermost position, respectively, of the said third housing.

3. A pedestal structure comprising a base, a horizontally disposed bevelled gear secured to the said base, a vertically disposed pivot mounted in the said base, a first housing rotatably mounted upon the said pivot of the base, a second housing in superposed positions to the said first housing and a third housing having a top plate, being open at its bottom'and telescopically receiving the said second housing, a motor supported by the said base, two oppositely arranged and vertically disposed bevelled gears freely rotatable on a horizontally disposed shaft supported by the base, the latter being driven by the said motor, a third horizontally disposed bevelled gear meshing both said vertically disposed bevelled gears, a vertically disposed screw spindle extending up wardly into the said second housing, the lower end of the said screw spindle being secured to the said horizontally disposed third bevelled gear, clutch means disposed between the said two vertically disposed bevelled gears to couple alternately one of the said last mentioned gears to the said driving shaft, the said screw spindle being mounted in the said second housing for rotation upon its longitudinal axis, a hollow spindle secured to the said top plate of the third housing, the said hollow spindle having inner thread and receiving the said screw spindle, guide means disposed in the said second housing to guide the said hollow spindle together with the said third housing for vertical movement of the latter relative to the said second housing, a pinion meshing the said bevelled gear secured to the said base, means for driving the said pinion by the said motor and means for controlling the said last mentioned driving means for the said pinion, the said pinion being adapted to turn the said housings relative to the said base, and supporting means secured to the top plate of the third housing adapted to support a drawing board or the like.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 656,256 Leisenring Aug. 21, 1900 1,529,022 Fraser Mar. 10, 1925 2,065,952 Trautmann Dec. 29, 1936 FOREIGN PATENTS Number Country Date] 946,052 France Mar. 3, 1949

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