Patents by Inventor Kojiro Yamaoka

Kojiro Yamaoka 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: 4886142
    Abstract: A hydraulic four-wheel drive apparatus for driving by a hydraulic motor four wheels: steering wheels and driving wheels, in which the steering wheels are driven by a variable capacity motor for the steering wheels and a front differential gear unit, and the driving wheels are driven by a fixed capacity motor for the driving wheels, so that, when a vehicle turns, a swash plate of the variable capacity motor associates with operation of a steering handle, thereby accelerating the speeds of steering wheels.
    Type: Grant
    Filed: June 27, 1988
    Date of Patent: December 12, 1989
    Assignee: Kanzaki Kokyukoki Mfg. Co. Ltd.
    Inventors: Kojiro Yamaoka, Toshiro Azuma, Kazuhiko Yano, Ryota Ohashi
  • Patent number: 4882940
    Abstract: The present invention provides a simple and compact power transmission mechanism for a tractor or similar vehicle having mounted thereto a mechanical attachment such as a lawn mower. The power transmission mechanism includes an engine which transmits driving power to ground engaging wheels through a driving power transmission unit and to the mechanical attachment through a driving speed changing unit positioned atop the transmission unit and operatively interconnected to the drive shaft thereof. The driving speed changing unit includes an input shaft which receives engine driving power for driving the drive shaft through a differential gear unit. Engine power is transmitted to the attachment through a belt from a power take-off unit coupled to the input shaft.
    Type: Grant
    Filed: February 3, 1989
    Date of Patent: November 28, 1989
    Assignee: Kanzaki Kokyukoki Mfg. Co. Ltd.
    Inventors: Kojiro Yamaoka, Toshiro Azuma, Koichiro Fujisaki, Hideaki Okada
  • Patent number: 4867008
    Abstract: A transmission formed of aluminum die casting which has disposed therein a differential gear and speed reduction gears. The case is provided at the outer surface thereof with a hydro-static transmission system. The transmission case is divided horizontally into three sections at two planes, one of which passes through the axis of each driving axle of the tractor, the other of which passes through the axes of the speed reduction gears.
    Type: Grant
    Filed: November 7, 1986
    Date of Patent: September 19, 1989
    Assignee: Kanzaki Kokyukoki Mfg., Co. Ltd.
    Inventors: Kojiro Yamaoka, Shusuke Nemoto
  • Patent number: 4827783
    Abstract: In a key-shift transmission which comprises a shifting mechanism including a shifter fork (51) slidable on a fork shaft (50), an interlocking mechanism for preventing a shifting operation at the engaged condition of clutch (22) is provided by utilizing a latching mechanism disposed between the fork and fork shaft. In addition to a spring-biased latching ball (55) cooperating with a plurality of annular grooves (52N-52R) of the fork shaft for the latching purpose, a second ball (61) is provided which is received in the fork and is operative to interlock such fork in cooperation with the annular grooves. The fork shaft is supported rotatably and is operatively connected to a clutch-disengaging pedal (26) so that the shaft is rotated at the clutch-disengaged condition to an angular position where additional cut-out grooves (65) formed to the fork shaft unlock the fork.
    Type: Grant
    Filed: September 18, 1987
    Date of Patent: May 9, 1989
    Assignee: Kanzaki Kokyukoki Mfg. Co., Ltd.
    Inventors: Kojiro Yamaoka, Hideaki Okada
  • Patent number: 4819508
    Abstract: Separate left and right hydrostatic transmissions (17) for controlling rotation of left and right final drive wheels (11) of a working vehicle independently are disposed laterally inwardly of the drive wheels in a vertical posture such that, while an input shaft (18) is directed axially outwardly of the vehicle, an output shaft (19) is directed axially inwardly of the vehicle. To each of the hydrostatic transmissions is attached a L-shaped gear box (20) which extends over axially inward and laterally outer sides of the hydrostatic transmission and supports the axle (21) of final drive wheel. Within the box is housed first and second reduction gear trains which form L-shaped transmission path between the output shaft and axle.The hydrostatic transmission (17) and gear box (20) of each side may be handled as a unit in assembling the transmission system and are compactly disposed in the proximity of each final drive wheel (11).
    Type: Grant
    Filed: November 18, 1987
    Date of Patent: April 11, 1989
    Assignee: Kanzaki Kokyukoki Mfg. Co., Ltd.
    Inventors: Kojiro Yamaoka, Shusuke Nemoto
  • Patent number: 4809796
    Abstract: Separate left and right hydrostatic transmission (15) for controlling rotation of left and right final drive wheels (11) of a working vehicle independently are disposed laterally inwardly of the drive wheels in a vertical posture such that, while an input shaft (23) extends upwardly, an output shaft (24) extends downwardly. To each of the hydrostatic transmissions is attached a L-shaped gear box (16) which extends over lower and outer sides of the hydrostatic transmission and supports the axle (17) of final drive wheel at its upstanding portion. within the box is housed first and second reduction gear trains which form a L-shaped transmission path between the output shaft and axle.
    Type: Grant
    Filed: October 15, 1987
    Date of Patent: March 7, 1989
    Assignee: Kanzaki Kokyukoki Mfg. Co. Ltd.
    Inventors: Kojiro Yamaoka, Shusuke Nemoto
  • Patent number: 4784013
    Abstract: The present invention relates to a driving apparatus which is attached with a HST system transmission and used for a light tractor or the like and which is simple in construction and easy to assemble, inspect and repair.
    Type: Grant
    Filed: November 7, 1986
    Date of Patent: November 15, 1988
    Assignee: Kanzaki Kokyukoki Mfg. Co. Ltd.
    Inventors: Kojiro Yamaoka, Koichiro Fujisaki
  • Patent number: 4781259
    Abstract: Construction of an axle driving apparatus disposing therein left and right driving axles and differential gears of a traveling vehicle. The driving case of the axle driving apparatus is formed of aluminum die casting to enable assembly by reducing machined portions as much as possible, and divided into a first driving case and a second driving case by a parting line P passing through the center of the axle, so that the built-in surface along the parting line P is used to put, between the split portions, the differential gear or other part, thereby enabling the assembly and saving the manhours for the assembly work.
    Type: Grant
    Filed: October 24, 1986
    Date of Patent: November 1, 1988
    Assignee: Kanzaki Kokyukoki Mfg. Co. Ltd.
    Inventors: Kojiro Yamaoka, Shusuke Nemoto
  • Patent number: 4727759
    Abstract: A front and rear transmission casing are joined to form a single casing. Upper and lower input shafts are received and supported by the front casing. The lower input shaft drives a change speed gearing with a speed change shaft and a pinion shaft. The pinion shaft has a pinion gear located on a further end of the shaft and engages a ring gear of a differential. The upper input shaft drives a clutch driven shaft through a PTO clutch unit. A rear PTO shaft is driven by the clutch driven shaft and extends out of the rear casing. A mid PTO shaft is also driven by the clutch driven shaft and extends out of the front casing.
    Type: Grant
    Filed: August 19, 1986
    Date of Patent: March 1, 1988
    Assignee: Kanzaki Kokyukoki Mfg. Co. Ltd.
    Inventors: Kojiro Yamaoka, Shusuke Nemoto
  • Patent number: 4679673
    Abstract: A reversing clutch assembly (13) for marine angle drive which allows the engine (11) to be mounted horizontally. To provide a required inclination to propeller shaft (12), the transmission path is bent within clutch casing (14) by using conical gearing. The casing (14) includes three horizontal shafts or input shaft (15), clutch shaft (17) and intermediate shaft (18), and only one inclined shaft or output shaft (16). Clutch shaft (17) has thereon forward and backward direction gears (28, 29) which are driven by the input shaft (15) through gear trains comprising spur gears, and double-acting clutch mechanism (30) for selectively coupling each of the direction gears (28, 29) to clutch shaft (17). The conical gearing is disposed only between clutch shaft (17) and output shaft (16) and thus includes only one conical gear (38).Parallel arrangement of three shafts (15, 17, 18) and use of single conical gear (38) contribute to save cost of the clutch assembly.
    Type: Grant
    Filed: December 6, 1985
    Date of Patent: July 14, 1987
    Assignee: Kanzaki Kokyukoki Mfg. Co., Ltd.
    Inventors: Kojiro Yamaoka, Kazuhiko Yano, Kazuhiko Ohtsuki
  • Patent number: 4673055
    Abstract: In a self-propelled working vehicle having a speed change mechanism wherein a plurality of change gears journaled on a shaft are coupled one at a time by key means disposed within and shiftable along the shaft, fluid-actuated clutch is provided for interrupting input of power to the speed change mechanism before shifting operations. For protecting gear-engaging clutch portion of the key means for damage, fluid pressure applied to the clutch from a disengaged condition thereof is increased gradually by a relief valve including a pressure-modulating control piston. For disengaging the clutch before shifting operations, an unloader valve is provided which is actuated by moving a speed change lever along a direction other than the key-shifting direction.Relief valve means also acting as an unloader valve for disengaging the clutch is disclosed. Differential-locking clutch is also disclosed which is operated by fluid for actuating the clutch in the transmission path.
    Type: Grant
    Filed: May 20, 1986
    Date of Patent: June 16, 1987
    Assignee: Kanzaki Kokyukoki Mfg. Co., Ltd.
    Inventors: Kojiro Yamaoka, Hideaki Okada
  • Patent number: 4664210
    Abstract: A hydraulic steering system for use in four-wheel running vehicles or the like of small size and low horsepower. The steering system and a hydraulic system for lifting a working implement are both operable by a single hydraulic pump without the necessity of using a variable displacement hydraulic pump or providing two hydraulic pumps for the two systems. The steering system is operable by an engine of low horsepower.
    Type: Grant
    Filed: January 17, 1986
    Date of Patent: May 12, 1987
    Assignee: Kanzaki Kokyukoki Mfg. Co. Ltd.
    Inventors: Kojiro Yamaoka, Toshiro Azuma, Shigenori Sakikawa, Jiro Shibata, Atsushi Odagaki
  • Patent number: 4148382
    Abstract: A vehicle power transmission for tractors and the like having a fluid operated speed-change mechanism which comprises a plurality of rotatably mounted speed-change gears arranged on a lay shaft and a plurality of fluid actuated clutches associated with the respective speed-change gears for selectively connecting each of the gears to the lay shaft. A brake is provided which selectively brakes the lay shaft at the non-operation state of the fluid operated speed-change mechanism. The brake prevents unexpected transmission of power through the speed-change mechanism at the non-operation state of the mechanism, thereby preventing problems such as an unexpected start of the vehicle.
    Type: Grant
    Filed: December 27, 1976
    Date of Patent: April 10, 1979
    Assignee: Kanzaki Kokyukoki Mfg. Co., Ltd.
    Inventors: Kojiro Yamaoka, Toshiro Azuma, Koichiro Fujisaki
  • Patent number: 4110898
    Abstract: A machine tool comprising one or plural storage magazines which are mounted along the vertical direction rotatably around a vertical axis on an upstanding support frame structure at a side of working station. Each of the magazines stores at the periphery thereof a plurality of spindle heads, workpiece supporting jigs or tool supporting heads which are alternatively set one by one to a set position at the working station for operation on workpieces. Alternative setting of such heads or jigs is achieved by a selective rotation of each magazine and by a selective lifting and lowering of the head or jig between the set position and a store position just above such set position. Floor space required for storing and exchanging the heads or jigs is largely saved. A particular exchanging device for exchanging heads or jigs stored by the magazines for another heads or jigs is provided which greatly enlarges processings possibly carried out at the working station.
    Type: Grant
    Filed: March 1, 1977
    Date of Patent: September 5, 1978
    Assignee: Kanzaki Kokyukoki Mfg. Co., Ltd.
    Inventors: Kojiro Yamaoka, Toshihide Mihara, Akira Tanaka