US 1341988 A
Description (OCR text may contain errors)
E. R. KOECHLIN.
APPLICATION FILED on. 5. msfi 1,341,988. Patented June 1, 1920.
"UNITED STATES!" EMILE RAYMOND KOECHLIN, or AMSTERDAM,NETHERLANDS, ASSIGNOR T0 NAAMLOOZEVENNOOTSCHAP wsnuw'n J. AHRENTD & zooms INDUSTRIE- EN HANDELSVEREENIGING, or AMSTERDAM, NETHERLANDS, A COMPANY on THE NETHERLANDS.
Patented June 1,
Application filed Gctober 5, 1918. Serial No. 257,637.
To all whom it may concern:
Be it known that I, EMILE RAYMOND KonoHLIN, a subject of the Queen ofthe Netherlands, residing at Amsterdam, in the Kingdom of the Netherlands, have invented certain new and useful Improvements in Drawing-Tables, of which the following is a specification.
My present invention relates to drawing tables and is more particularly applicable to drawing tables of the type comprising a drawing board connected with two adjacent joints of an articulated parallelogram guide the third joint of which forms a fixed fulcrum and is connected with the board by a link which extends beyond said fulcrum and is provided with a counterweight for counterbalancing the board, whereas the fourth joint is pivoted to a member whose freedom of motion is counteracted by a suitable friction device.
My invention is designed to provide improved means for avoiding any undue change in the form of the parallelogram guide as long as the board is normally used, but allowing at the same time the form of said link mechanism to be changed when desired by a comparatively slight pressure exerted on the board.
My invention will be best understood by reference. to the accompanying drawing, which will now be described, it being understood, however, that various changes may be made in the details of construction and arrangement by those skilled in the art, without departing from the spirit and scope of my invention.
In the drawing:
Figure 1 is a side elevation of a drawing table embodying my invention, Fig. 2 being a sectional view on a larger scale of that part of the drawing table which comprises the 1 Securedto the lever 7 carrying the coun-' terweight 8 and concentric relative to the fulcrum 2 is a circular rod 9 passing through hole in a sleeve'lO secured to a cross-piece 11 betweenthe legs 12 and 13 of the table, a cap 14 being screwed on said sleeve. Lo-
'cated. within said sleeve is helical spring .15 one end of which bears against the screw cap 14, the other end bearing against a brake shoe 16. Said brake shoe 16, which normally contacts with the circular rod 9, is adapted to press said rod against a second brake shoe 17 I V A screw bolt 18 which is provided with a handle 19 and screwed through the cover of the cap 1%, is adapted to be screwed into the sleeve 10 through a sufficient distance to press the brake shoe 16 against the rod 9 even if the cap 14: is turned back as far as possible. 7 V
When using my improved drawing table I put the helical spring 15 under proper tension by means of the screw cap 14, whereby the rod 9 is gripped between the brake shoes 16 and 17, and I adjust this gripping force so that the rod 9 does not tend to slide within the sleeve 10 when I use the board in the usual manner, that is to say, as long as I am drawing, and that an increased pressure on the board is required for causing a displacement of said rod. this gripping force will be initially adjusted to suit the requirements, but, once adjusted, it should preferably be left unchanged. The bolt 18 is normally screwed backso far that its end does not engage the brake shoe 16. v V
The arrangement described evidently prevents the board from being unduly displaced parallel with itself as long as it is normally used, but it .allows of this movement being effected, if desired, by an increased pressure exerted on the board.
Now, if I wish to firmly secure the rod 9 within the sleeve 10, for instance, if at any moment it should be desired to increase the load of the board, I turn the screw bolt 18 As a matter of course,
until the frictional resistance of the brake I claim as new and desire to protect by Letters Patent of the United States:
1. In a drawing'table, the combination of v a drawing board,'a support, a pivot on said 2. In a drawing table, the combination of 7 I support, a link connected to said board and to said pivot, a curved rod concentric with said pivot and secured to saidjlink,'a sleeve secured to said support, saidrod extending through said sleeve, a brake-shoe adapted to engage sald rod, a cap "in threaded -engagement with said sleeve, a spring interposed between said shoe and cap, and a screwspindie in threaded engagement with said cap and adapted to bear against said shoe.
In testimony whereof I affix mysignature.
EMILE RAYMOND KOEGHIJIN. '5
Vitnesses D. KLIJN, M. ALVARADO.