Clamping tool

Claim 1

A clamping tool comprising in combination: a plurality of clamp elements movable in a plane toward and away from one another; means biasing said elements to predetermined distance from one another in that plane; interconnection means connected to each of said clamp elements for moving them together without change in their relative position; actuation means Carried by said interconnection means for altering the position of the said elements relative to one another in said plane as a function of the degree of relative movement between said actuation means and said interconnection means and as an incident to such movement; in which said interconnection means comprises an elongate tube; in which said clamp elements comprise a pair of L-shaped metal strips the lower legs of which extend in opposite directions and the other legs of which are welded at their upper end regions to a lower end region of said tube and are resilient and comprise said biasing means; said clamp elements, when relaxed, extending from their connection with said tube such that their other legs converge toward one another at their juncture with said lower legs and are capable of being forced, against said bias, to a position in which they extend substantially in parallel over a portion of their length; and in which said actuation means comprises a pushrod slidably mounted axially within said tube and having an upper end extending from the upper end of the tube and a lower end extending from the lower end of the tube, a knob fixed to the upper end of the pushrod, and a cam carried by the lower end of the pushrod and disposed between said clamping elements, said cam comprising a camming surface over a portion of its length which is engageable with surfaces of said clamping elements as an incident to relative movement between them occasioned by axial movement of the pushrod relative to the tube, the camming surface being tapered from its upper to its lower end in a degree which increases toward its lower end, the width of said camming surface toward its upper end being sufficient to force said clamping elements to substantially parallel position when carried relatively downwardly by said pushrod.