Abstract: Extension springs that can be manufactured to a small size with a precise free length are described herein. An extension spring comprises a first drawbar member and a second drawbar member that extend along a same direction. The extension spring further comprises a compression spring coil that surrounds respective portions of the draw bar members. At either end of the spring coil are positioned end caps that surround the drawbar members. The end caps provide flat surfaces on which the ends of the spring coil rest in a resting position of the extension spring. The end caps are held against bent ends of arms of the drawbar members by tension of the spring coil. When the drawbar members are drawn apart from one another, the end caps compress the spring coil. Compression of the spring coil causes forces that resist the motion of the drawbar members apart from one another.

Abstract: An improved keyboard, and a data terminal incorporating same, is disclosed. The present keyboard advantageously includes a keyboard membrane having, on an upper side, a plurality of raised regions upon which character designators can be placed. A plurality of upper key members are disposed on a lower side of the keyboard membrane. Each upper key member is advantageously structurally adapted to return itself, after removal of an actuating force, to an unactuated position. The raised regions on the upper side, and the upper key members on the lower side of the keyboard membrane are advantageously molded from a single elastomeric layer, thereby replacing hundreds of parts in conventional computer-style keyboards using sliding-plunger type key mechanisms. A plurality of lower key members are disposed on a circuit board underneath the keyboard membrane. The lower key members are structurally adapted to prevent “rock over” when a user depresses a raised region somewhat off-center.

Abstract: A cable management assembly for use with equipment racks wherein equipment panels are fastened along vertical mounting rails of the rack. In one embodiment, the assembly includes an elongated trough having a back wall, a bottom wall and a front wall. The back wall is constructed to be fastened to the mounting rails of the equipment rack, and the bottom wall extends a sufficient distance forward so that the trough accommodates wire or fiber optic cables terminated at one or more equipment panels fastened to the rack above the back wall of the trough. A door has its bottom edge hinged to the front wall of the trough, and the door extends at a first position to protect cables terminated at one or more equipment panels mounted on the rack above the back wall of the trough. The door can be swung to a second position to permit access to the cables and the panels at which they terminate.

Abstract: A public telephone that has the ability to return change to a user is described. A coin changer that is advantageously sized to fit within the space available in a public telephone built to BellCore standards advantageously replaces the coin collect/reject equipment located after a "coin-discrimination" portion of conventional coin mechanisms found in such telephones. Existing public telephones may be readily retrofitted with the present coin changer. A three-position "trigate" is advantageously used to direct a coin to a return chute, or to one of two mechanical coin sorters within the coin changer. In one embodiment, each sorter is operable to sort three different coin denominations. Escrow capacity is included to temporarily store sorted coins. The sorters/escrow are advantageously readily-removable so that a first sorter may be removed and another inserted to provide sorting and escrow for other coins from other coin sets, including those from other countries.

Abstract: An anti-fraud string cutter for a coin telephone instrument having a serpentine coin path. The string cutter is fabricated as a stack of notched, slit, sheet metal plates having alternately off-set flat and wavy teeth which are adapted to snag and cut, between adjacent ones of the plates, any string threaded through said coin path by a fraudulent user. String cutters are advantageously to be mounted adjacent to one of the cusps of the serpentine path and above the coin return hopper.

Abstract: A linkage couples the coin return door of a coin telephone instrument to a cam mounted in the coin return chute. When the coin return door is opened in the normal manner by a customer to retrieve coins from the coin return hopper, the cam closes a contact of a microswitch that completes a circuit. After a normal coin retrieval the door closes and the switch contact returns to open. Such momentary switch closures are considered normal. However, if foreign matter has been stuffed into the coin return hopper by a fraudulent user, the material will be engaged by a comb at the end of the cam, preventing the coin return door from closing normally. When the door is prevented from closing normally and remains open for more than a few moments, the switch remains actuated, keeping the circuit closed for longer than normal thereby signaling the signaling the telephone company that the phone has been tampered with.

Abstract: A coin telephone instrument having a serpentine coin path is provided with string grabbers positioned at cusps in the coin path to engage the string of a tethered coin deposited by a fraudulent user. Each string grabber assembly is comprised of a pair of facing and arcuately converging lip surfaces which guide the string toward the surfaces' initial point of convergence. The grabbers, working in tandem, will stop the tethered coin during its descent before it reaches the escrow hopper, trap door and coin steering vane, thereby frustrating the fraudulent attempt. If the fraudulent user pulls back on the string to retrieve the tethered coin, the converging lip surfaces engage the string forcing it past the initial point of convergence and into the path of a sheet metal slit cutter which severs the string tether.

Abstract: A system and method for providing video telephone call capabilities through a combination of standard audio telephone lines and video cable TV lines. A person at a video telephone may place a call to a person who does not have a video telephone but who does have cable television service. The system transmits the audio portion of the conversation over standard telephone lines in the manner of a conventional, non-video telephone call. The video portion of the conversation, on the other hand, is concurrently transmitted over in-place cable television equipment to be viewed on the call recipient's television. Alternately, protocol conversion may be utilized in the telephone network to allow a caller and a recipient each having respectively incompatible video telephone equipment to freely communicate with one another.

Abstract: An apparatus assembles threaded parts in a cramped space. The apparatus grasps a nut so that an axial force may be placed on the nut while it is being threaded. The apparatus also provides a mechanism for rotating the nut in a relatively low torque fashion that permits a user to feel a cross-threaded orientation.