Abstract: A screen repair apparatus is disclosed for temporarily repairing holes or worn screen elements of screens used in gyratory or vibratory screening machines in the coal mining and rock quarrying industries. The apparatus is comprised of a flat plate which covers the damaged area of screen on the screen's top, a number of duplex jaws which are used to clamp the apparatus to the lower surface of the screen elements, and a clamping means, including an attachment rod which draws together the plate and duplex jaws on either side of the screen elements, thereby clamping the two to the screen. The screen repair apparatus also is comprised of a set of cauls, which are disposed between the clamping means and the upper surface of the plate and which distribute the force exerted by the clamping means across the face of the upper surface of the plate.

Abstract: An adjustable hanger has a hanger body, opposed carrying arms that are slidably extendable from the hanger body to increase or decrease the size of the hanger, and a connecting rod that is rotatable to cause the carrying arms to be extended or retracted from the hanger body. The connecting rod can be a hollow tube wherein the ends of the opposed carrying arms are inserted into the connecting rod and wherein oppositely wound spiral grooves on the inside of the connecting rod mate with projections on the ends of the carrying arms so that rotation of the connecting rod causes the carrying arms to be extended or retracted from the connecting rod. Alternately, oppositely wound spiral grooves formed on the outside of the carrying arms may mate with projections on the inside of the connecting rod so that rotation of the connecting rod causes the carrying arms to be extended or retracted from the connecting rod.

Abstract: A pipe sealing apparatus is provided to include an outer arcuate support shell defining an arc equal to or less than one hundred eighty degrees securing an inflatable pneumatic bladder to a concave surface thereof, with the bladder including a flexible polymeric sealing plate mounted thereon in confrontation and in with continuous communication with an associated pipe to be sealed. The apparatus includes an inflation chamber to direct inflation into the bladder as required.

Abstract: A laser alignment device which can be detachably mounted on a lumber cutting machine for assisting an operator in properly aligning a workpiece before cutting it into strips of desired widths. The device includes a frame which supports laser devices for projecting cutting-lines on the workpiece, which are visible to the operator. The laser devices are movable on the frame and their positions may be adjusted independent of each other so as to be in alignment with the respective saw blades disposed within the lumber cutting machine. The device further includes devices for locking the desired positions of the laser devices on the frame.