Abstract: A jack, comprising: a top plate adapted to contact a load; a base plate positioned below the top plate; at least one actuator coupled perpendicularly between the base plate and the top plate; wherein the at least one actuator is operable to move the top plate between a lowered position and a raised position to thereby lower and raise the load; and, at least one locking assembly adapted to lock the top plate in the raised position.

Abstract: A jack, comprising: a top plate having at least one adapter block mounted thereon and adapted to contact a load; an intermediate plate; a base plate; a first pair of actuators coupled between the base and intermediate plates; and, a second pair of actuators coupled between respective lowered portions of the intermediate plate and the top plate; wherein one of the first pair of actuators is positioned on the base plate on either side of the respective lowered portions; wherein the actuators are operable to move the top and intermediate plates between respective lowered and raised positions to thereby lower and raise the load; and, wherein a top adapter plate of the at least one adapter block is operable to slide between first and second positions across the top plate as the load is raised and lowered to maintain alignment of the top, intermediate, and base plates below the load.

Abstract: A jack, comprising: a top plate adapted to contact a load; a base plate positioned below the top plate; at least one actuator coupled perpendicularly between the base plate and the top plate; wherein the at least one actuator is operable to move the top plate between a lowered position and a raised position to thereby lower and raise the load; and, at least one locking assembly adapted to lock the top plate in the raised position.

Abstract: A jack, comprising: a top plate adapted to contact a load; a base plate positioned below the top plate; at least one actuator coupled perpendicularly between the base plate and the top plate; wherein the at least one actuator is operable to move the top plate between a lowered position and a raised position to thereby lower and raise the load; and, at least one locking assembly adapted to lock the top plate in the raised position.

Abstract: A jack, comprising: a top plate adapted to contact a load; a base plate positioned below the top plate; at least one actuator coupled perpendicularly between the base plate and the top plate; wherein the at least one actuator is operable to move the top plate between a lowered position and a raised position to thereby lower and raise the load; and, at least one locking assembly adapted to lock the top plate in the raised position.

Abstract: A jack, comprising: a top plate adapted to contact a load; an intermediate plate positioned below the top plate, the intermediate plate having a channel formed therein; a base plate positioned below the intermediate plate; a first pair of actuators coupled between the base plate and the intermediate plate, one of the first pair of actuators positioned on either side of the channel; and, a second pair of actuators coupled between the channel of the intermediate plate and the top plate; wherein the first and second pairs of actuators are operable to move the top plate and the intermediate plate between respective lowered positions and respective raised positions to thereby lower and raise the load.

Abstract: A jack, comprising: a top plate having at least one adapter block mounted thereon and adapted to contact a load; an intermediate plate; a base plate; a first pair of actuators coupled between the base and intermediate plates; and, a second pair of actuators coupled between respective lowered portions of the intermediate plate and the top plate; wherein one of the first pair of actuators is positioned on the base plate on either side of the respective lowered portions; wherein the actuators are operable to move the top and intermediate plates between respective lowered and raised positions to thereby lower and raise the load; and, wherein a top adapter plate of the at least one adapter block is operable to slide between first and second positions across the top plate as the load is raised and lowered to maintain alignment of the top, intermediate, and base plates below the load.

Abstract: A jack, comprising: a top plate adapted to contact a load; an intermediate plate positioned below the top plate, the intermediate plate having a channel formed therein; a base plate positioned below the intermediate plate; a first pair of actuators coupled between the base plate and the intermediate plate, one of the first pair of actuators positioned on either side of the channel; and, a second pair of actuators coupled between the channel of the intermediate plate and the top plate; wherein the first and second pairs of actuators are operable to move the top plate and the intermediate plate between respective lowered positions and respective raised positions to thereby lower and raise the load.

Abstract: A real time device polling method for multiplexed transmission of on/off constant bit rate data, such as voice data from a telephone call, over a cable data network is disclosed. The network serves as a shared bus for both the downstream and upstream traffic. The upstream channel is modeled as a stream of mini-slots. A cable modem termination system at the head end supports a number of cable modems attached to the cable network and connected to customer premises equipment. Allocation maps are transmitted on the downstream channel to the cable modems to define transmission opportunities on the upstream channel. The cable modem termination system polls the cable modems in an efficient way such that the overhead associated with the polling is minimized, and the availability of data transmission slots is synchronized with the data packet generation by the codec for the cable modem, which minimizes delay.

Abstract: A method for searching for a record in a table in a memory of a computer system. A table of records is organized into a group of arrays. A hashing algorithm locates a record in the table. Multiple hashing functions are executed concurrently, according to the number of arrays in the group, such that the record can be located relatively quickly in one of the arrays in the group. The table is analyzed to determine the information content of each bit in a string of bits comprising an index value associated with the table, according to Shannon's formula for information-theoretic entropy. The entropy associated with each bit in the string of bits provides a basis for selecting a subset of bits in the string of bits from which to obtain the seed values utilized in the hashing functions. A rotating mask, based on Neumann's code, is applied to the subset of bits to obtain different seed values for each of the hashing functions, thereby minimizing the correlation of the keys provided by the hashing functions.