Retread molds

A retread mold comprising first and second relatively movable supports, cooperative matrix portions carried by said supports, means for imparting relative movement to said supports to move said matrix portions between open and closed positions in the latter of which said matrix portions define an annular cavity adapted to receive a tire to be retreaded, means for selectively adjusting the distance between said movable supports with respect to the closed position of said matrix portions to accommodate tires of different widths in said cavity, means for locking said movable supports relative to each other in the closed position of said matrix portions at all distances between said movable supports when said matrix portions are in the closed position thereof, said locking means having cooperable locking portions carried by both said movable supports, means for adjustably varying the length of at least one of said locking portions to securely lock said movable supports together with said matrix portions in the closed position irrespective of the distance between said movable supports in said last-mentioned position, a pair of vertical supports, means mounting said first relatively movable support for vertical reciprocal sliding motion upon said pair of vertical supports, said length adjusting locking means including an interally threaded mounted for vertical sliding movement relative to said first support, said tube having upper and lower end portions, said lower tube end portion carries one of said cooperable locking portions a screw threaded to said internally threaded tube, a fluid cylinder and piston rod both diposed at least partially within said tube means connecting one of said cylinder and rod to said tube means connecting another of said cylinder and rod to said first support, and stop means for limiting the travel of said tube in a direction toward said locking portion of a second of said supports.