Abstract: An information-bearing laminar assembly, suitable for use as an identification card, is disclosed. The assembly is characterized by the provision therein of an embedded halftone image security feature that becomes visible essentially only when the assembly is view in transmitted light. The information-bearing laminar assembly comprises an inner information-bearing layer interposed between a first and a second light-transmissive protective outer layer. The inner layer contains both visible information-bearing indicia and an imagewise halftone pattern of laser-ablated microholes. The light-transmissivity of the information-bearing inner layer within said half-tone pattern is imagewise differentiated at each microhole as a function of the microhole's penetration depth. Sandwiched between the protective outer layers, the halftone pattern is imperceptible when the information-bearing laminar assembly is viewed in reflections and perceptible when the information-bearing laminar assembly is viewed in transmission.

Abstract: A mechanism for protecting an automatic teller machine against entry through the opening in the fascia when the machine which normally occupies the opening is not occupying the opening, including a door (33) for closing the opening, a link (25) for operating the door, a Geneva claw (29) for moving the link between door opening and door closing positions in response to movement of the machine between conditions respectively occupying and not occupying the opening, and a locking pawl (31) for preventing opening of the door when the machine is not occupying the opening.

Abstract: Apparatus for automatically eliminating a sway condition of a trailer towed by a tow vehicle. A hitch connects the trailer to the tow vehicle and has a sensor for providing signals corresponding to the hitch lateral force for operating the trailer brakes.

Abstract: Apparatus for automatically eliminating a sway condition of a trailer having surge brakes and towed by a tow vehicle. The hitch connects the trailer to the tow vehicle and has a reaction wheel for sensing hitch lateral force and for automatically controlling the trailer brakes to eliminate the sway condition.

Abstract: A speed sensor for a vehicle wheel has a rotating tone wheel and a stationary E-shaped magnetic sensor having a sensing pole of square loop magnetic material positioned between two switching poles. A coil is wound on the sensing pole and the poles are magnetized to periodically reverse the flux in the sensing pole as the teeth on the tone wheel alternately pass the switching poles to induce a signal voltage in the coil corresponding to wheel speed and substantially free of noise components due to misalignment and vibrations of the tone wheel upon relative rotation of the tone wheel and magnetic sensor.

Abstract: A speed sensor for a vehicle wheel has a rotating tone wheel with a stationary magnetic sensor having a pair of sensing poles positioned proximate the tone wheel teeth. Coil means are wound on the poles and the poles are magnetized to induce a signal voltage in the coil means corresponding to wheel speed. The poles are phased relative to the teeth on the tone wheel to reduce noise voltage components in the wheel speed signal voltage due to axial misalignment and vibration of the tone wheel. The poles may be phased 180.degree. relative to one another with respect to the teeth on the tone wheel so that one pole is in registry with a tooth when the other pole is in registry with a space between two teeth. With this arrangement the combined reluctance of the poles is approximately constant.