Patents by Inventor Robert N. Stedman

Robert N. Stedman has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4413708
    Abstract: Industrial trucks commonly include a unitary frame having a roller mast and carriage assembly mounted forwardly thereon. The ability of such trucks to traverse narrow aisles is limited and their stability is normally increased with use of outriggers, counterweights, or the like. The vehicle (10) of this invention, such as an industrial truck, comprises a rear frame (14) and a pair of laterally spaced front frames (16) pivotally mounted forwardly on the rear frame (14). A roller mast (20) and carriage (26) is adapted to be mounted forwardly on the rear frame (14), between the front frames (16). The vehicle (10) will thus exhibit high degrees of maneuverability and stability by its ability to pivot the front frames (16) towards and away from each other, depending on the job task under consideration.
    Type: Grant
    Filed: March 5, 1982
    Date of Patent: November 8, 1983
    Assignee: Caterpillar Tractor Co.
    Inventor: Robert N. Stedman
  • Patent number: 4411329
    Abstract: Mobile vehicles, such as lift trucks, are normally mounted on pairs of front and rear wheels for locomotion purposes. The rear wheels are steerable to move the truck into various work positions. However, the turning radius and maneuverability of vehicles of this type are limited, particularly when working in narrow aisles. The vehicle (10) of the present invention includes a frame assembly (13), a plurality of wheels (72,74) mounted on the frame assembly (13) for universal movement about a pivot point (110), and a support and drive system (70) for driving the wheels (72,74) and for infinitely positioning the wheels (72,74) relative to a supporting surface (11) to move the vehicle (10) in any chosen direction.
    Type: Grant
    Filed: January 11, 1982
    Date of Patent: October 25, 1983
    Assignee: Caterpillar Tractor Co.
    Inventor: Robert N. Stedman
  • Patent number: 4312427
    Abstract: Free-lift of a lift truck carriage is desirable without extension of the uprights, along with the capability to extend the carriage above the uprights, all while retaining clear forward vision and a rigid mast structure. Herein, relatively movable mast members (14a,14b) are shorter than relatively fixed mast members (12a,12b), the sheaves (28a,28b) are affixed to the movable members (14a,14b), the chains (30a,30b) are attached to the carriage (16) over the sheaves (28a, 28b) and to the relatively fixed members (12a,12b), while the jacks (24a,24b) act between the relatively fixed (12a,12b) and movable (14a,14a) members. Slide bars (44a,44b) are movably mounted to the relatively movable members (14a,14b) and to the carriage (16).
    Type: Grant
    Filed: March 10, 1980
    Date of Patent: January 26, 1982
    Assignee: Caterpillar Tractor Co.
    Inventor: Robert N. Stedman
  • Patent number: 4267749
    Abstract: A compact reversible variable speed clutch transmission and differential including a rotable input shaft having a drive gear (76), forward and reverse gears (88,84) engaged with the drive gear on opposite sides thereof, and a pair of selectively operable clutches each having an input (92) connected to an associated one of the forward and reverse gears and an output (94). The clutch outputs are connected to the inputs (110) of a variable speed nutating transmission (120) which includes a pair of independently rotatable outputs (116). The transmission includes a pair of nutating elements (130) each having a surface (132) which is a non-cylindrical surface of revolution. The elements are mounted for rotation by a mounting device (126,128) for rotation and there is included a pair of drive units (134) one for each nutating element, fixedly connecting thereto and to an associated one of the outputs.
    Type: Grant
    Filed: October 12, 1979
    Date of Patent: May 19, 1981
    Assignee: Caterpillar Tractor Co.
    Inventors: Robert O. Chambers, Robert N. Stedman
  • Patent number: 4257653
    Abstract: A track assembly (11) for a track-type vehicle (10) includes a pair of link assemblies (17,18) having inboard links (20,24) thereof solely engageable with the idler (13) and track rollers (14) of the vehicle (10). When the vehicle (10) traverses wet or swampy ground, wherein it proves desirable to utilize relatively wide track shoes (16), torsional loads imposed on the shoes can cause premature wear or damage to the shoes (16). The track assembly (11) exhibits a high resistance to such torsional loads imposed thereon and adapts itself for use in lieu of a standard track assembly on a conventional track-type vehicle. A method for prolonging the service life of the track assembly comprises interchanging the two link assemblies (17,18).
    Type: Grant
    Filed: August 23, 1979
    Date of Patent: March 24, 1981
    Assignee: Caterpillar Tractor Co.
    Inventors: Thomas C. Meisel, Jr., Robert N. Stedman
  • Patent number: 4230199
    Abstract: A work vehicle (10) such as, for example, a tractor (74) or loader (27) has a center of gravity (12), a body (14) and first and second continuous track assemblies ( 18,20). In the use of the tractor (74), for example, forwardly locating the center of gravity (12) can increase penetration of a bulldozer (76) on the tractor (74) during bulldozing operations. During ripping operations, penetration of a ripper (78) on the tractor (74) can be increased by rearwardly locating the center of gravity (12). Apparatus (22) is provided for controllably moving the body (14) relative to both of the track assemblies ( 18,20). Said apparatus (22) thus controllably shifts the center of gravity (12) of the tractor (74) relative to both of said track assemblies ( 18,20) for selectively increasing penetration of the ripper (78) or bulldozer (76) depending upon the operation being performed by said tractor (74).
    Type: Grant
    Filed: December 12, 1978
    Date of Patent: October 28, 1980
    Assignee: Caterpillar Tractor Co.
    Inventor: Robert N. Stedman
  • Patent number: 4221525
    Abstract: An apparatus (10) is used for transporting one or more elongated members (12), such as logs (12) or pipes. The absence of developed roadways into tree cutting sites, for example, requires an apparatus (10) for transporting logs (12) over difficult terrain from the site to other locations. In the apparatus (10) for transporting the elongated member (12), first apparatus (20) controllably engages a first end portion (14) of the elongated member (12) in supporting relationship in response to being urged between the first end portion (14) and the ground (32) in a direction (34) generally longitudinal relative to the elongated member (12). Second apparatus (26) controllably engages a second end portion (16) of the elongated member (12) and maintains the first end portion (14) in supporting relationship with the first apparatus (20).
    Type: Grant
    Filed: August 28, 1978
    Date of Patent: September 9, 1980
    Assignee: Caterpillar Tractor Co.
    Inventor: Robert N. Stedman
  • Patent number: 4207967
    Abstract: A lift mechanism for lift vehicles of a type including an operator's station and a carriage arranged for vertical travel upon a mast assembly. In one embodiment, the lift mechanism includes a lever arrangement, preferably an overhead guard structure, pivotably connected to the vehicle and operatively connected with the carriage by means of a pivotable link. In other disclosed embodiments, the lever mechanism is also an overhead guard structure providing an overhead guard function for the operator station while the mast assembly preferably includes a fixed upright portion and at least one movable upright portion supporting the carriage, the movable overhead guard structure and link being operable to cause vertical travel of both the movable upright portion and carriage. An additional embodiment has the overhead guard lift the movable upright and the short lift cylinder lifts the carriage.
    Type: Grant
    Filed: February 6, 1978
    Date of Patent: June 17, 1980
    Assignee: Caterpillar Tractor Co.
    Inventor: Robert N. Stedman
  • Patent number: 4204578
    Abstract: A ground-engaging implement assembly for installation on a vehicle includes a U-shaped frame having a bight portion extending around one end of the vehicle and a pair of spaced leg portions extending along and connected to the respective sides of the vehicle. Each of the leg portions of the frame has a mounting face thereon and an implement such as a ripper mechanism is connected to each mounting face for penetrating material at the opposite sides of the vehicle.
    Type: Grant
    Filed: May 26, 1978
    Date of Patent: May 27, 1980
    Assignee: Caterpillar Tractor Co.
    Inventor: Robert N. Stedman
  • Patent number: 4197049
    Abstract: A self loading scraper has upper and lower members of an ejector pivotally interconnected at a pivot. The upper member is automatically pivoted about the pivot rearwardly relative to the lower member as the ejector is moved forwardly for ejecting the load from the bowl.
    Type: Grant
    Filed: March 20, 1978
    Date of Patent: April 8, 1980
    Assignee: Caterpillar Tractor Co.
    Inventors: Robert N. Stedman, James E. Gee
  • Patent number: 4174757
    Abstract: A material ripping vehicle includes first and second traction units, and a frame having an upright pivot axis for steerably connecting the traction units. The second traction unit has a pair of spaced apart ground engaging members and a ripping apparatus is mounted on the frame and positioned between the ground engaging members.
    Type: Grant
    Filed: October 3, 1977
    Date of Patent: November 20, 1979
    Assignee: Caterpillar Tractor Co.
    Inventor: Robert N. Stedman
  • Patent number: 4172486
    Abstract: A track assembly for a vehicle has a plurality of grousered track shoes and a cleaning member extending between at least two of the shoes. The member moves relative to the track shoes as the track assembly deflects and avoids the packing of dirt and material between the grousers of the track shoes.
    Type: Grant
    Filed: March 16, 1978
    Date of Patent: October 30, 1979
    Assignee: Caterpillar Tractor Co.
    Inventors: Robert N. Stedman, Robert T. McNeely
  • Patent number: 4166511
    Abstract: A crawler vehicle rides on four spaced-apart crawler track assemblies which extend lengthwise beneath the vehicle body. Ground pressure is reduced and traction, flotation and stability are enhanced by a suspension system which enables the forward portion of each track assembly to rise and fall independently of the others to accommodate to irregular terrain. For similar purposes, the suspension system enables the outer and inner track assemblies below the right portion of the vehicle to oscillate outward and inward as a unit about an axis extending lengthwise of the vehicle while enabling the outer and inner track assemblies below the left side of the vehicle to oscillate as a unit in a similar but independent manner.
    Type: Grant
    Filed: June 27, 1977
    Date of Patent: September 4, 1979
    Assignee: Caterpillar Tractor Co.
    Inventor: Robert N. Stedman
  • Patent number: 4165137
    Abstract: A track shoe adapted for use in an endless track assembly for a track-type vehicle comprises a base having a pair of sidewalls formed integrally thereon. The sidewalls extend away from the base in converging relationship with respect to each other and terminate at edges which may be welded together. The method for making the track shoe comprises the steps of forming a blank to include the base and sidewalls of the track shoe, bending the sidewalls towards each other and then welding them together, if so desired.
    Type: Grant
    Filed: August 26, 1977
    Date of Patent: August 21, 1979
    Assignee: Caterpillar Tractor Co.
    Inventor: Robert N. Stedman
  • Patent number: 4152991
    Abstract: A ripping apparatus includes a housing having a bearing assembly therein which is connected to a support member of a vehicle, a ripper mechanism having a shaft member pivotally mounted in the bearing assembly, a lever arm connected to the shaft member, a material ripping element connected to the bottom of the shaft member, and a fluid operated linear actuator connected to the support member and to the lever arm for rotating the ripping element between a retracted position and a transversely disposed working position. The ripping apparatus is particularly adapted to shatter a compacted railroad bed underneath the rail and supporting ties.
    Type: Grant
    Filed: June 27, 1977
    Date of Patent: May 8, 1979
    Assignee: Caterpillar Tractor Co.
    Inventors: Robert N. Stedman, James E. Gee
  • Patent number: 4147218
    Abstract: Mounting structure provides for coupling a bulldozer blade to a crawler tractor which has four track assemblies each of which may oscillate vertically independently of the others and pairs of which may oscillate laterally relative to the tractor body and which is therefore not adaptable to the coupling of bulldozer push arms to the track frames at each side of the tractor in the conventional manner. A pair of push arms with universal joints at each end extend between pairs of the track assemblies to couple the blade to suspension frame members. A mounting member, pivotable vertically by a centrally located lift cylinder, connects to the blade at another universal joint. To resist side loads, which can be severe owing to the close spacing of the push arms, stabilizing links extend diagonally from the mounting member to the ends of the blade and the links may be fluid cylinders to facilitate tipping and tilting of the blade.
    Type: Grant
    Filed: September 29, 1977
    Date of Patent: April 3, 1979
    Assignee: Caterpillar Tractor Co.
    Inventor: Robert N. Stedman
  • Patent number: 4141601
    Abstract: An endless track assembly comprises a plurality of track shoes pivotally interconnected by a link assembly secured thereto. The link assembly comprises a plurality of links, each releasably secured to one of the track shoes by a plurality of bolts. The track shoe comprises a lug disposed on each lateral side thereof and a pair of longitudinally spaced flanges releasably secured to the links by the bolts. In a first embodiment of this invention, the flanges are formed out of sidewalls of the track shoe to form an integral part thereof whereas in a second embodiment of this invention the flanges are formed on one component of a two-component track shoe.
    Type: Grant
    Filed: August 26, 1977
    Date of Patent: February 27, 1979
    Assignee: Caterpillar Tractor Co.
    Inventor: Robert N. Stedman
  • Patent number: 4140186
    Abstract: An earthmoving apparatus has first and second traction units and a connecting device for connecting the second traction unit to the first traction unit in rearwardly spaced relationship. A ripper is carried by the connecting device intermediate the traction units. An adjusting device selectively adjusts the positioning of the ripper on the connecting device and includes a jack having a first portion carried by the connecting device and a second selectively extensible portion connected to the ripper for selectively positioning the ripper relative to and independently of the connecting device.
    Type: Grant
    Filed: May 25, 1977
    Date of Patent: February 20, 1979
    Assignee: Caterpillar Tractor Co.
    Inventor: Robert N. Stedman
  • Patent number: 4123119
    Abstract: An endless track assembly comprises a plurality of track shoes pivotally interconnected by a link assembly secured thereto. The link assembly comprises a plurality of links with each track shoe being releasably secured to each pair of laterally spaced links by a plurality of bolts. Each track shoe comprises a base plate disposed on each pair of links, a track plate disposed on the base plate and at least one clamping plate straddling the track plate. The bolts sequentially extend through the clamping plate, the track plate, the base plate and each pair of the links for releasably securing the track shoe to the link assembly. In one embodiment of the invention, the clamping plate is mounted on a pair of spacer blocks whereas in a second embodiment the clamping plate is mounted directly on the base plate.
    Type: Grant
    Filed: August 26, 1977
    Date of Patent: October 31, 1978
    Assignee: Caterpillar Tractor Co.
    Inventor: Robert N. Stedman
  • Patent number: 4122959
    Abstract: An articulated construction vehicle, such as a backhoe comprises front and rear frames pivotally interconnected together directly by a universal pivot connection and a link universally interconnected between the frames. The link is disposed vertically below the universal pivot connection whereby the frames are adapted for relative pivotal and vertical movement.
    Type: Grant
    Filed: May 9, 1977
    Date of Patent: October 31, 1978
    Assignee: Caterpillar Tractor Co.
    Inventor: Robert N. Stedman