Abstract: A spool assembly comprising a housing structure, a spool rotatably retained in an interior region of the housing structure, and a sealed sheath encasing the housing structure to define a barrier for the encased housing structure and the rotatably retained spool. The spool assembly further comprises a locking arm disposed outside of the sealed sheath and configured to operably engage the spool through the sealed sheath and through the housing structure in a manner that does not penetrate the sealed sheath, where the locking arm prevents the spool from rotating relative to the housing mechanism when operably engaged with the spool. The locking arm may disengage from the spool in a hands-free manner when the spool assembly is loaded into a bay of an additive manufacturing system.

Abstract: A spool assembly for use in an additive manufacturing system, comprising a spool rotatably retained in a sealed sheath in a hub-less manner, and a locking mechanism configured to operably engage with the spool to prevent the spool from rotating.

Abstract: A print head for use in a fused deposition modeling system, the print head includes a cartridge assembly and a liquefier pump assembly retained by the cartridge assembly.

Abstract: A print head assembly that includes a print head carriage and multiple, replaceable print heads that are configured to be removably retained in receptacles of the print head carriage. The print heads each include a cartridge assembly and a liquefier pump assembly retained by the cartridge assembly.

Abstract: A print head for use in a fused deposition modeling system, the print head includes a cartridge assembly and a liquefier pump assembly retained by the cartridge assembly.

Abstract: A liquefier assembly for use in an extrusion-based additive manufacturing system, the liquefier assembly comprising a downstream portion having a first average inner cross-sectional area, and an upstream having a second average inner cross-sectional area that is less than the first inner cross-sectional area, the upstream portion defining a shoulder configured to restrict movement of a melt meniscus of a consumable material.

Abstract: A method for building a three-dimensional model with an extrusion-based additive manufacturing system having an extrusion head, the method comprising depositing a consumable material from a liquefier assembly at an extrusion rate to substantially normalize a meniscus height within the liquefier assembly.

Abstract: An open center fluid controller (15) controls the flow from a pump (11) to a steering cylinder (17) and to a downstream auxiliary device (99) requiring a predetermined minimum flow availability. The open center fluid controller (15) includes controller valving (19) having a neutral position (N) a normal operating position (R) and a maximum displacement position (R-M). The controller defines an auxiliary fluid path providing communication between an inlet port (31) and an auxiliary or power beyond port (87), which is in communication with the auxiliary device (99). The auxiliary fluid path includes a neutral variable orifice (AN) having a decreasing flow area as the valving (19) is displaced toward the maximum displacement position (R-M). The valving defines an auxiliary flow control orifice (AA) providing communication from the inlet port to the auxiliary port (87) when the valving approaches the maximum displacement position.

Abstract: An open center fluid controller (15) controls the flow from a pump (11) to a steering cylinder (17) and to a downstream auxiliary device (99) requiring a predetermined minimum flow availability. The open center fluid controller (15) includes controller valving (19) having a neutral position (N) a normal operating position (R) and a maximum displacement position (R-M). The controller defines an auxiliary fluid path providing communication between an inlet port (31) and an auxiliary or power beyond port (87), which is in communication with the auxiliary device (99). The auxiliary fluid path includes a neutral variable orifice (AN) having a decreasing flow area as the valving (19) is displaced toward the maximum displacement position (R-M). The valving defines an auxiliary flow control orifice (AA) providing communication from the inlet port to the auxiliary port (87) when the valving approaches the maximum displacement position.

Abstract: A steer-by-wire vehicle steering system and method of controlling such a steering system when steering into and away from a steering stop. In one embodiment, the system includes a steering reaction device (55) including a fluid displacement mechanism (71), and a valve arrangement (95) operable to vary the steering reaction provided to the vehicle operator. In another embodiment, there is a “friction” reaction device (111) including an electromagnetic coil (115) which can have a varying signal (61) applied to it to vary the steering reaction the coil imposes on a movable member (113) of the device (111). In either embodiment, the reaction device includes a spring arrangement (93;131), such that rotation of the steering wheel (51) is in opposition to a spring force.

Abstract: A steer-by-wire vehicle steering system and method of controlling such a steering system when steering into and away from a steering stop. In one embodiment, the system includes a steering reaction device (55) including a fluid displacement mechanism (71), and a valve arrangement (95) operable to vary the steering reaction provided to the vehicle operator. In another embodiment, there is a “friction” reaction device (111) including an electromagnetic coil (115) which can have a varying signal (61) applied to it to vary the steering reaction the coil imposes on a movable member (113) of the device (111). In either embodiment, the reaction device includes a spring arrangement (93;131), such that rotation of the steering wheel (51) is in opposition to a spring force.

Abstract: A full fluid-linked steering system, especially for use in on-highway steering, in which the system includes a fluid controller (21) including a fluid meter (65) operable to provide follow-up movement to controller valving (87,89), in response to the flow of fluid through the meter. The controller (21) includes a centering or biasing spring assembly (75) which provides sufficient torque that, upon rotation of the steering wheel (W), fluid is communicated to the steering actuator (19) without relative displacement of the valving, thus providing driver with the desired road feel. The system includes an EHC valve assembly (23) which controls flow to or from the actuator (19) in response to appropriate input signals (113,115) to maintain steered wheel to steering wheel registry.

Abstract: A steering control unit having a gerotor gear set (15) including a ring member (35) and a star member (37) which orbits and rotates within the ring. Adjacent the rearward surface (49) of the star (37) is and end cap (17). The invention provides an improved sealed star arrangement, in which the star defines an annular groove (51) in which are disposed a seal ring (55) and a backup ring (57). In accordance with the invention, the inside diameter (61) of the backup ring (57) is less than the diameter of the inner surface (59) of the groove, such that there is a radial squeeze on the backup ring (57). The axial dimension of the seal ring (55) and backup ring (57) together is less than the axial dimension of the groove (51), so there is no axial squeeze on the rings, thus eliminating the binding of the gerotor star which has been common with prior art sealed star arrangements.

Abstract: A hydrostatic power steering system comprising a fluid motor (19) which receives pressurized fluid from a controller (17) in response to the rotation of a vehicle steering wheel (W). As the motor (19) or the steered wheels reach the stops, control logic (31) receives signals (37,77) representing steered wheel and steering wheel position, respectively, and generates appropriate command signals (33,27) to a pressure reducing/relieving valve (15) and to a proportional electromagnetic valve (23), respectively, closing the valve (15) somewhat, and opening the valve (23). A pressure differential is built between an additional fluid path (21) and the high pressure conduit (15c) between the controller (17) and the fluid motor (19). Pressure is communicated through the valve (23) into the conduit (51c), and back into the fluid meter (43) of the controller, preventing any further rotation thereof in response to an attempt to turn the steering wheel, thus eliminating travel limit slip.

Abstract: A fluid controller (15) for use with an unequal area cylinder (25) having a rod end area A and a head end area B. The controller valving (27) includes, in one embodiment, a flow amplification path (101) for only one direction of steering. In another embodiment, the controller valving (27) includes flow amplification in both directions of steering, but with the ratios being different. In either case, the ratio of flow to the head end to flow to the rod end equals the ratio B/A, whereby the fluid controller requires the same number of turns, lock-to-lock, for either direction of steering.

Abstract: A hydrostatic power steering device is disclosed, which may be either a fluid controller (15) or a torque generator 111. The device is of the type including a housing (19;135) defining a fluid inlet port (29;113) and a return port (31;115). The device includes valve means (36;171) defining a neutral position and a first operating position. The device includes a gerotor mechanism (23;143) for imparting follow-up movement to the valve means in response to fluid flow through the gerotor, and a follow-up mechanism (49,51;183,185) transmits the follow-up movement to the valve means. The valve means defines a return fluid region (87,89,31g;205,197,157) which comprises part of the main fluid path. The return fluid region is isolated from the follow-up means and from the interior of the valving.

Abstract: An improved T-ring wiper seal and seal carrier assembly for use in the fluid end of a reciprocating pump.

Abstract: An improved seal carrier assembly for use in the fluid end of a reciprocating pump.