Patents Represented by Law Firm Zalkind & Shuster
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Patent number: 4614127Abstract: A rack and pinion gearing in a steering housing is provided, with eccentric bushing bearings at each end of the pinion shaft. The bushings are outer races of roller bearings which carry the shaft and which bushings are carried in the housing rotatively supported whereby rotation of each bushing serves to radially align the shaft in proper coaxial position in the assembly of the device, so that the rack and pinion teeth have accurate relative position. Thus, the eccentricity of the bushing bearings serves to shift respective ends of the shaft radially and the bearing bushings have relatively thin extending skirts which can be deformed so as to lock into notches in the housing when the pinion shaft is properly positioned.Type: GrantFiled: May 29, 1984Date of Patent: September 30, 1986Assignee: Zahnradfabrik Friedrichshafen, AG.Inventor: Dieter Elser
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Patent number: 4608612Abstract: The channel output signal from the center track read head of a magnetic tape unit clocks the side channel outputs of two other read heads through a logic circuit to operate a skew status indicator. The same center channel signal provides tape speed information displayed by a speed status indicator, while the amplitude condition of all channel outputs are displayed by amplitude status indicators. All indicators register a correct or acceptable condition and an incorrect condition as well as the directional deviation of the incorrect condition.Type: GrantFiled: February 26, 1985Date of Patent: August 26, 1986Inventor: Earl H. Rayfield
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Patent number: 4599908Abstract: A pressure deformable body of a transducer is formed with a plurality of passage holes through which paths are established for a signal medium conducted thereto through a rigid base on which the body is mounted. Portions of the body material when loaded bulge into the passage holes causing constriction thereof to vary the intensity of the signal medium transmitted. The passage holes are spaced in an array arranged to distribute hole constriction in a load-pattern reproducing manner.Type: GrantFiled: March 18, 1985Date of Patent: July 15, 1986Inventors: Thomas B. Sheridan, John L. Schneiter
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Patent number: 4593718Abstract: A booster steering valve control of the kind that comprises a pair of valve pistons reciprocal in a rotative valve body are driven by a fork shaped member at the end of a steering spindle. The fork shaped member comprises a pair of spaced actuator pins which engage in openings of the respective valve pistons. Thus, the valve body and the fork shaped member have a common axis about which the actuator pins rotate. A particular construction of the invention resides in the displacement of the actuator pins such that their axes are not in a common plane with the steering spindle axis but offset so that the surfaces of engagement between the actuator pins with the respective valve pistons and the spindle axis are coplanar. Engagement is maintained by spring bias acting on the valve pistons.Type: GrantFiled: March 15, 1985Date of Patent: June 10, 1986Assignee: Zahnradfabrik Friedrichshafen, AGInventors: Armin Lang, Helmut Knodler
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Patent number: 4590965Abstract: A booster steering valve control device of the kind having a rotative valve body within a steering housing with a pair of piston valves operative upon rotation of a steering spindle is provided with reaction chambers at corresponding ends of the piston valves. The reaction chambers are isolated from an inlet chamber within the steering housing by means of closure caps. The closure caps are secured in place by a resilient clamp held by a bolt carried in a bore of the valve body in which the valve pistons are reciprocal.Type: GrantFiled: March 15, 1985Date of Patent: May 27, 1986Assignee: Zahnradfabrik Friedrichshafen, AG.Inventors: Armin Lang, Helmut Knodler
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Patent number: 4564338Abstract: A vane pump having a flow regulating bypass valve activated by outlet pressure to direct excess flow back to the inlet is provided with a channeling having an element comprising a plug insertable in the valve housing, which plug has a specially shaped flow bend in the form of an arcate groove that forms a smooth transition for combined flow from a tank fed inlet and from the bypass valve to the pump inlet. This is effected by connecting a channel from the tank inlet and bypass valve to a channel for flow return to the pump inlet which channels are angularly related. Since the valve housing is die cast the difficulty of providing, in a casting, an exactly shaped smooth surfaced and accurately dimensioned transition passage between the aforementioned channels is overcome by the invention.Type: GrantFiled: April 1, 1985Date of Patent: January 14, 1986Assignee: Zahnradfabrik Friedrichshafen, AG.Inventor: Rudolf Ilg
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Patent number: 4558631Abstract: Separate branch conduits extend from a common pump to two fluid power operated systems. One of the branch conduits supplies a relatively low volume of fluid through a pilot flow conduit to a steering control valve in one of the systems to adjust its operating pressure when the steering control valve is displaced from its neutral position. The other branch conduit delivers pressurized fluid directly to the steering control valve on a priority basis. A pressure regulating valve connected between the other branch conduit and the pilot flow conduit isolates the steering system from a higher pressure in the other fluid power operated system and adjusts the operating pressure in the steering system to meet steering load demands.Type: GrantFiled: November 23, 1982Date of Patent: December 17, 1985Assignee: Zahnradfabrik Friedrichshafen, AGInventor: Rolf Fassbender
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Patent number: 4557344Abstract: A servosteering control valve is provided with fluid reaction chambers which are pressued responsive to the speed of a vehicle for effecting a simulated steering resistance wherein at low speed, as in parking, there is no steering resistance and resistance increases with speed via feedback from the chambers of a double acting servomotor. The novel feature of the arrangement herein utilizes a coaction between the inlet flow control passage and return flow control passage of a steering control spool or piston valve, one such valve for each chamber. This is in conjunction with throttle passages disposed between the manually shiftable piston valves and a valve housing. Such passages are created by portions of the shiftable valves having elements slightly smaller in diameter than the diameter of the housing bore or bores in which the valves are shiftable. A single bore is used where the valves are coaxially integral and respective bores are used where the valves are separably movable.Type: GrantFiled: August 23, 1984Date of Patent: December 10, 1985Assignee: Zahnradfabrik Friedrichshafen, AG.Inventor: Armin Lang
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Patent number: 4555975Abstract: A hydraulic power steering system having an unbalanced piston servomotor and a pair of identical control valve pistons controlling flow of pressurized fluid to the servomotor for balanced directional displacement of the servomotor piston and to separately control depressurization of feedback chambers acting on the control valve pistons. Pressurized fluid is supplied directly to the feedback chambers from the servo-steering pump through flow restrictors, one of which is externally adjusted to select the degree of road sensing feedback generated to oppose manual actuation of the control valve pistons.Type: GrantFiled: May 25, 1982Date of Patent: December 3, 1985Assignee: Zahnradfabrik Friedrichshafen, AG.Inventors: Armin Lang, Helmut Knodler
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Patent number: 4553390Abstract: A hydrostatic steering system having a hand operated metering pump and steering control valve regulating and distributing fluid flow from a servo pump to a piston servomotor of the differential pressure surface type. A compensation valve disposed in the pressure line leading to one of the opposed chambers of the piston servomotor, is actuated by a differential pressure surface dimensioned to establish a constant ratio of pressures prevailing in the opposed pressure chambers in the neutral steering position while the metering pump is ineffective to produce any differential pressure. During active steering, the compensation valve is bypassed through a check valve.Type: GrantFiled: October 19, 1984Date of Patent: November 19, 1985Assignee: Zahnradfabrik Friedrichshafen, AG.Inventors: Karl-Heinz Liebert, Werner Tischer, Rolf Fassbender
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Patent number: 4553908Abstract: A rotary slide vane pump for steering booster systems has a flow control valve which bypasses flow from outlet side to suction side with increase in speed as heretofore known. The flow channels or passages that conduct bypass flow change the direction of the flow at a juncture point between passages, such directional change being a right angle, radially downstream from the bypass valve to longitudinally at the point of juncture to the suction side, likewise as heretofore known. In the present invention there is provided a transition piece between the channels at the right angle juncture in the form of a screw in the pump body and having a flat face disposed flush with the longitudinal channel and transversely of the radial channel. The provision of such transition piece has been found to effect an increase in suction pressure when bypass flow is added to normal suction flow, such increase being over and above that effected by the prior art.Type: GrantFiled: April 28, 1981Date of Patent: November 19, 1985Assignee: Zahnradfabrik Friedrichshafen, AG.Inventor: Johann Merz
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Patent number: 4553389Abstract: In a hydrostatic auxiliary power steering apparatus, a short-circuit passage of a control valve establishes a restricted flow path from a pump pressure line to a reservoir return line in the neutral position of the control valve wherein all other flow paths are blocked. A fixed flow restrictor in the pump pressure line conducts a continuous flow from one of two pumps connected to the pressure line for regulation of the fluid power steering circuit by the pressure drop across the flow restrictor. If one of the pumps is of the variable volume type, the pressure downstream of the flow restrictor is utilized to regulate pump flow adjustment. If fluid under operating pressure is supplied to both the fluid power steering circuit and another fluid operating circuit, a flow dividing valve controlled by the pressure differential across the flow restrictor distributes pressurized fluid between the two fluid circuits.Type: GrantFiled: August 3, 1982Date of Patent: November 19, 1985Assignee: Zahnradfabrik Friedrichshafen, AG.Inventors: Werner Tischer, Karl-Heinz Liebert, Rolf Fassbender
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Patent number: 4553447Abstract: Parallel ball bearing arrays are utilized in a pressure support means for a rack to reduce friction of a stationary pressure means supporting a moving rack in engagement with a drive pinion. The rack and a pressure pad have face to face coacting ball races on each side of the rack and so oriented that median planes of a pair of facing races are at an angle to the median plane of the rack. Accordingly, a train of balls on each side of the rack in the respective pair of coacting races has a median plane at an angle to the median plane of the rack on each side of the rack. Such orientation gives support normal to the rack and laterally as well, at the area where the rack engages the pinion.Type: GrantFiled: November 30, 1983Date of Patent: November 19, 1985Assignee: Zahnradfabrik Friedrichshafen, AG.Inventor: Ansgar Betz
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Patent number: 4536133Abstract: A regulatable vane pump is provided with regulating apparatus incorporated in the pump having a differential pressure piston operable responsive to booster steering flow demand wherein the piston carries a flexible leaf spring having a flat surface which serves as a shut off member against ports in a restrictor member. Actuation of the regulating piston carries the leaf spring toward the ported member to progressively shut off restrictor ports in the face of the ported member, either partially or fully depending upon the ported arrangement. As ports are gradually closed off regulation of the pump discharge is effected at various demand pressures after linear rise of rate of discharge up to a regulating point. Thereafter, there is wide separation of characteristics of regulating curves or lines for differing pressure demands. The overall effect produces a precise regulation within narrow limits as well as an economy of manufacture.Type: GrantFiled: March 22, 1984Date of Patent: August 20, 1985Assignee: Zahnradfabrik Friedrichshafen, AG.Inventor: Gunther Seidl
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Patent number: 4516784Abstract: A seal assembly comprised of a pair of concentric rings radially spaced with a tortuous or convoluted channel therebetween in which is carried a rubber-like compressible seal element that extends beyond the radial surfaces of the rings. The inner ring has passages for flow between registering passages of assembled components, e.g., radial piston pumps. Such passages are inside the perimeter of the seal element and within convolutions. The outer ring has apertures for passage of screws for assembling the components together, thereby compressing the sealing element during assembly to effect a tight seal. The compressed material is displaced into adjoining concavities molded into the sealing element within the thickness of the concentric carrier rings.Type: GrantFiled: August 9, 1984Date of Patent: May 14, 1985Assignee: Zahnradfabrik Friedrichshafen AGInventor: Johann Merz
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Patent number: 4495769Abstract: A control valve for booster power steering has a back pressure check valve openable by pressure caused by wheel jolting, which check valve connects between a servopump pressure passage of the control valve through the inner bore of a valve sleeve operable within a housing bore to the inlet of a metering pump. Such valve ensures that the steering is "closed" under all circumstances including during steering to prevent pressure jolts being transmitted from the vehicle wheels due to road roughness. However, after completion of a steering operation high pressure can build up within the valve sleeve causing expansion of the valve sleeve and jamming within the housing bore, making operation difficult. Accordingly, a pressure limiting valve is provided connected to relieve the pressure within the valve sleeve bore.Type: GrantFiled: August 13, 1981Date of Patent: January 29, 1985Assignee: Zahnradfabrik Friedrichshafen, AG.Inventors: Werner Tischer, Karl-Heinz Liebert, Rolf Fassbender
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Patent number: 4492487Abstract: Coded data imprinted in close spaced relation on data sheets retained within a loose leaf binder is selectively marked through cutout openings in a transparent overlay mask. The mask is positioned in proper alignment over each of the data sheets by means of aligning slots through which at least two of the binder rings project.Type: GrantFiled: April 1, 1982Date of Patent: January 8, 1985Inventor: Woodrow Spear
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Patent number: 4488401Abstract: A flow regulating channel in a servo steering valve controls exhaust flow with varying restriction from a fluid operating motor while controlling operation of a separate steering servo motor on a priority basis. An operational control valve for the fluid operating motor has a valve passage that is open only in the neutral position to complete a recirculating flow path from a common servo pump through the flow regulating channel that is fully open in the neutral position of the steering valve.Type: GrantFiled: May 28, 1982Date of Patent: December 18, 1984Assignee: Zahnradfabrik Friedrichshafen, A.G.Inventor: Werner Tischer
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Patent number: 4483237Abstract: A control valve in a power boost steering system uses hydraulic power for wheel straightening after a steering operation wherein a valve spool is reciprocal with a worm shaft which has an end threadedly carrying a non-rotative but slidable collar to compress springs as the worm shaft is rotated by virtue of being keyed against rotation. Thus, rotation of the worm shaft can actuate the collar axially in either direction against oppositely disposed compression springs depending on direction of steering rotation of the worm shaft by a manually operated steering spindle. When manual steering force on the steering spindle is released, the compressed spring expands to axially move the worm shaft and thus the valve spool through a neutral position which exhausts the cylinder chambers. However, the continued expansion of the compressed spring moves the valve spool to a position whereat pressure flow and exhaust of the cylinder chambers is reversed from the original steering direction.Type: GrantFiled: May 10, 1983Date of Patent: November 20, 1984Assignee: Zahnradfabrik Friedrichshafen, AG.Inventor: Dieter Elser
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Patent number: 4479400Abstract: An impact damping or cushioning means is provided to overcome the noise occasioned when a reciprocating slide block member, to which steering rods are secured, is limited in motion by engaging the ends of a housing slot in which the member slides. Such slide block is secured to a drive rod in the housing, which may be a pinion driven rack or operated by a pressure piston, and protrudes through the slot for connection to steering rods. The construction effects a damped or cushioned initial impact engagement of increasing resilient resistance up to the point of metallic non-yielding engagement of either end of the slide block with the respective end of the slot. Thus, the cushioning means at each end of the travel is of deforming, compressible rubber-like plastic material compressed in comfinement during initial impact in a recess which may be in the slide block or in the housing slot edge.Type: GrantFiled: April 13, 1982Date of Patent: October 30, 1984Assignee: Zahnradfabrik Friedrichshafen, AG.Inventor: Wolfgang Rieger