Abstract: An educational instrument for numbers for providing students with an educational tool that would be fun and challenging. The educational instrument for numbers includes a base member having a top side, a recessed portion in the top side, a first longitudinal slot, a second longitudinal slot, a first longitudinal groove extending from the recessed portion and terminating near a first end of the base member, a second longitudinal groove extending from the recessed portion and terminating near a second end of the base member, a matrix of numbers disposed in the recessed portion, a first cover means slidably disposed in the first longitudinal slot and movable over the recessed portion, and a second cover means slidably disposed in the second longitudinal slot and movable over the recessed portion and over the first cover member.

Abstract: A three piece axle and wheel spindle assembly for vehicular trailers wherein a damaged spindle may be replaced at will, characterized by corresponding axle and spindle flange plates, the former defining a positive spindle flange plate positioners, the latter a removable plate, inter-locking therewith. Lefthand and righthand spindle flange plates each form a cam slide, corresponding to a cam positioner against the axle flange plate and a receptor flange seat for the axle plate. Removal and replacement of one or the other wheel spindle may be effected en route and without any axle dismantling from the trailer. Fastening bolts of the three piece assembly are readily accessible, due to their disposition at right angles to the axis of the axle.

Abstract: The present doorlock closure secures existing doors having conventional doorknobs against entry by enveloping the doorknob with opposed cavity compartments of knob confining segments. Upper and lower housing segments are hinged together such that they may mount elements which form a cam-lever, segment interlocking assembly. The assembly includes a spring-loaded latch and lockable latch lever in the upper segment and a corresponding cam latch release in the lower segment. The housing segments themselves are hinged together for facile clamping upon the doorknob of a door, securing it against entry by persons having a passkey to the doorknob which retains a turnkey lock therein.