Abstract: A mechanism is provided for maintaining an open door in a selected fixed position includes a keyed shaft which passes through a plurality of elliptically shaped discs via apertures centrally located in the discs are mounted. The long axis of each disc is aligned to that of the other discs and the discs are pressed together from either side along the axis of the shaft between two compression springs. Angled stop members located to the outside of the compression springs displace the discs along their long axis at a small angle from the plane perpendicular to the shaft. The small angle is chosen to produce a substantially circular projection of the discs in a plane perpendicular to the shaft. The shaft, with its mounted discs, springs, and angled stop members, is placed within a housing of cylindrical cross section having an interior diameter selected such that the discs are in frictional contact with the internal surface of the housing and the shaft is thus slidably but frictionally disposed in the housing.

Abstract: A mechanism is provided for maintaining an open door in a selected fixed position includes a hydraulic cylinder having first and second ends. One end of a shaft axially disposed in the cylinder, passes through a hydraulic seal at one end of the cylinder. A piston is axially disposed on the shaft near its other end, and includes o-rings for sealing it against the cylinder walls. The piston includes first and second axially-disposed bores. First and second discs, each including an aperture are axially mounted on the shaft in contact with the opposing faces of the piston and are positioned such that the aperture of each is substantially aligned with one of the bores and blocks the other bore. The discs are held against the faces of the piston with a predetermined amount of force.

Abstract: A merchandise display rack comprises a series of chutes that may be connected side by side or stacked. Each chute has a central slideway with a push plate slide, which is pulled forward by an elongated spring. Horizontal, lateral extension panels having parallel back to back V-grooves across the width thereof may readily be broken off along straight lines to selected widths and interlocked to the sides of the slideway. A longitudinal connector member interlocks with the lateral extension panels and vertical side panels to form the chute.

Abstract: The merchandise display rack of this invention is particularly adapted for cylindrical ice cream containers. Each rack in the assembly has in-turned side rails so that a row of containers can be supported on their cylindrical sides and fed forwardly by a pusher plate pressing against the trailing container. A stretchable tension member, such as a long coil spring, is attached to the rear of each rack at both sides, brought forward around spaced pulleys at the front and then directed back behind the pusher plate that engages the trailing container. The individual racks may be secured together side by side and vertically with sufficient vertical clearance to accommodate a row of containers.

Abstract: Apparatus for advancing packaged goods on a shelf comprises an upright pressure plate carried on the end of a flexible belt. The belt is carried on a roll which is spring biased to wind the belt thereon so that a row of articles positioned along the belt and engaged by the pressure plate will be pushed toward the front of the shelf as each successive article is removed.

Abstract: An improved utility blade for use with the conventional type of utility knife handle and having means near its cutting points for shielding the cutting points and portions of the cutting edges of the blade from the contents of cardboard cartons.