SEPTEMBER, 1952
455
A NEW AND USEFUL LABORATORY CLAMP ROY I. GRANTOM Lion Oil Company, El Dorado, Arkansa~ QUITE frequent,ly in a chemirtd laboratory, particularly
one in which pas work is being done, the occasion arises when it is n e k s a r y t o seal straight-wall glass tube with a rubber stopper so as t o allow the maintenance of a moderate pressure in the system. Since no commercially made clamp is designed for this particular application the usual recourse has been t o hold the stopper in place with wire. This method has the obvious disadvantage of uneven pressure distribution and, consequently, a poor rubber-to-glass seal. The clamp shown in the photograph mas designed to fill this need. The clamp consists of a standard rubber hose clamp (such as Arthur H. Thomas Catalog KO. 3284), a headplate, and two connecting bolts with washers and wing nuts. The hose clamp should be large enough t o fit around the glass tube and allow some additional space for the insulating tape (rubber or asbestos). The bolts should be approximately X 3 in. and should have one end flattened and bent so as t o fit under the edge of the hose clamp. Those shown in the photograph were made from X 4 in. toggle bolts. The head-plate can he made of any metal and should he large enough t o insure reasonably uniform distribution of the pressure as the plate is screwed down The head-plate can be modified as shown t,o permit the passage of tubes through the stopper.
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