摘要:
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.
摘要:
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.
摘要:
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. The auxiliary flow control orifice (AA) has a flow area operable to permit the predetermined minimum flow availability to the auxiliary device, even as a maximum steering operation (R-M) is taking place.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.