US3250411A - Hydraulic control system for tractor loader - Google Patents

Hydraulic control system for tractor loader Download PDF

Info

Publication number
US3250411A
US3250411A US420681A US42068164A US3250411A US 3250411 A US3250411 A US 3250411A US 420681 A US420681 A US 420681A US 42068164 A US42068164 A US 42068164A US 3250411 A US3250411 A US 3250411A
Authority
US
United States
Prior art keywords
conduit
valve
pressure
boom
chamber
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US420681A
Other languages
English (en)
Inventor
Salna Karl
Herbert A Mark
Carl C Baker
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Dresser Industries Inc
Frank G Hough Co
Original Assignee
Frank G Hough Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Frank G Hough Co filed Critical Frank G Hough Co
Priority to US420681A priority Critical patent/US3250411A/en
Priority to GB51179/65A priority patent/GB1133955A/en
Priority to DE19651634816D priority patent/DE1634816B1/de
Priority to FR43232A priority patent/FR1464266A/fr
Application granted granted Critical
Publication of US3250411A publication Critical patent/US3250411A/en
Assigned to DRESSER INDUSTRIES, INC., A CORP. OF DEL. reassignment DRESSER INDUSTRIES, INC., A CORP. OF DEL. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: INTERNATIONAL HARVESTER COMPANY
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
    • F15B11/17—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors using two or more pumps
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F3/00—Dredgers; Soil-shifting machines
    • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
    • E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
    • E02F3/34—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets with bucket-arms, i.e. a pair of arms, e.g. manufacturing processes, form, geometry, material of bucket-arms directly pivoted on the frames of tractors or self-propelled machines
    • E02F3/3405—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets with bucket-arms, i.e. a pair of arms, e.g. manufacturing processes, form, geometry, material of bucket-arms directly pivoted on the frames of tractors or self-propelled machines and comprising an additional linkage mechanism
    • E02F3/3408—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets with bucket-arms, i.e. a pair of arms, e.g. manufacturing processes, form, geometry, material of bucket-arms directly pivoted on the frames of tractors or self-propelled machines and comprising an additional linkage mechanism of the parallelogram-type
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F3/00—Dredgers; Soil-shifting machines
    • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
    • E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
    • E02F3/36—Component parts
    • E02F3/42—Drives for dippers, buckets, dipper-arms or bucket-arms
    • E02F3/422—Drive systems for bucket-arms, front-end loaders, dumpers or the like
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F3/00—Dredgers; Soil-shifting machines
    • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
    • E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
    • E02F3/36—Component parts
    • E02F3/42—Drives for dippers, buckets, dipper-arms or bucket-arms
    • E02F3/43—Control of dipper or bucket position; Control of sequence of drive operations
    • E02F3/431—Control of dipper or bucket position; Control of sequence of drive operations for bucket-arms, front-end loaders, dumpers or the like
    • E02F3/432—Control of dipper or bucket position; Control of sequence of drive operations for bucket-arms, front-end loaders, dumpers or the like for keeping the bucket in a predetermined position or attitude
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E02F9/2221—Control of flow rate; Load sensing arrangements
    • E02F9/2239—Control of flow rate; Load sensing arrangements using two or more pumps with cross-assistance
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E02F9/2278—Hydraulic circuits
    • E02F9/2292—Systems with two or more pumps

Definitions

  • Excavating vehicles include those generally known as front end tractor loaders which would make use of the invention described herein. However, it is understood that this invention can be utilized with a wide variety of machinery in which hydraulic equipment is used to excavate and lift earth or other loads.
  • a further advantage in applicants novel invention is that with articulated vehicles the unloading valve may be located near the pumps and reservoir on the rear sec tion of the vehicle so that the low pressure lines need not extend to the front section. Thus fluid line losses are reduced and the hydraulic fluid operates at a lower temperature with a consequent saving in available horse power. It therefore is an object of this invention to allow a substantial reduction in fluid line losses by providing a new and improved unloading valve which may be located on the rear section of an articulated vehicle.
  • Still another purpose of this invention is to provide a dual pump unloading valve which may be rendered inoperative in response to the position of the boom arms and in which the point in which the valve is rendered inoperative may be readily adjusted.
  • Still another object is to provide a dual pump unloading valve in which the valve is rendered inoperative in response to operating means such as an electrical current and in which said electrical current is supplied in response to the position of the boom arms.
  • FIGURE 1 is a side elevation view of a tractor loader showing a hydraulic system with an unloading valve, relief valve and adjust-able linkage means positioned according to one embodiment of the present invention
  • FIGURE 2 is a detailed sectional view of the loading valve of FIGURE 1;
  • FIGURE 3 is a diagrammatic view of a modified form of the adjustable linkage means of FIGURE 1 in which an electrical circuit is employed.
  • FIGURE 1 shows a complete tractor loader with the well-known loader attachment consisting of boom arms 12 which carry the bucket assembly 14.
  • the hydraulic system for operating the boom includes extensible hydraulic rams 16.
  • the bucket assembly is operated through linkage means 20 which are in turn operated by extensible ram 18.
  • Hydraulic fluid under pressure to operate the rams is supplied by high pressure pump 26 and low pressure pump 24.
  • Both pumps are of the conventional vane type construction and are selected so that pump 26 delivers a high pressure, small flow rate while pump 24 delivers a low pressure, large flow rate.
  • Prime mover 28 mounted on the tractor loader 10 supplies the turning force to operate the pumps.
  • the pumps withdraw supply fluid from hydraulic reservoir 22 through common hydraulic conduit 30.
  • Low pressure fluid is directed from pumps 24 through conduit 32 to unloading valve 36, while high pressure fluid is directed from pump 26 through conduit 34 to unloading valve 36.
  • Conduit 56 provides a return line from the unloading valve 36 to the reservoir 22.
  • Hydraulic control valve 38 is of the wellknown open center spool valve type and controls the operation of the boom arms and bucket assembly.
  • Conduit 48 directs fluid from unloading valve 36 to control valve 38 while conduit 54 provides a return line to reservoir 32.
  • Manually operated control link-age 44 operates the position of spool valve 40 which in turn directs fluid through lines 50 to rams 16 to raise and lower the boom arms.
  • Manually operated control linkage 46 operates spool valve 42 which in turn directs fluid through lines 52 to ram 18 to control the position of bucket 14.
  • Relief valve 62 is provided to selectively render inoperative unloading valve 36.
  • Relief valve 62 can be of the open-closed type and receives fluid from unloading valve 36 through conduit 58 while directing fluid to reservoir 22 through conduits 60 and 56.
  • relief valve 62 is operated by the boom arms through a cam linkage consisting of arm 68, cam 66 and cam follower 64.
  • Cam follower 64 may be adjustable to selectively vary the predetermined position of the boom arms which will operate relief valve 62.
  • the cam linkage may conveniently be located in the operators compartment so that said predetermined position may easily be varied.
  • FIGURE 2 shows the improved unloading valve designated generally as 36.
  • Valve body -70 houses upper conduit 72 which provides direct fluid communication between conduits 34 and 48.
  • poppet valve 78 Located intermediate the valve housing in the upper conduit is poppet valve 78 which is biased toward closure by spring 80. With the poppet valve in the open position vertical-bore 78 provides. fluid communication between upper conduit 72 and lower chamber 74.
  • Lower chamber 74 may be a horizontal bore in valve housing 70 which is adapted to receive piston 96.
  • Vertical bore 76 extends to the lower portion of housing 70 and is in fluid communication with conduit 32.
  • Return conduit 56 extends up through the lower margin of housing 70 in fluid communication with chamber 74.
  • Piston 96 is slidably carried in chamber 74 and supports opposed spacedapart piston heads 98 and 100.
  • Piston head 98 has a larger base area than piston head-100. In the position of the piston shown in FIGURE 2 piston head 98 is spaced from the left end of chamber 74 to define a space for biasing spring 99 which urges the piston to the right position.
  • a pilot relief valve 86 is provided in the unloading valve 36. Conduit 82 provides fluid communication between conduit 72 and pilot re- .lief valve 86. Spring 88 urges the pilot relief valve towards its closed position. Chamber 84 receives fluid from conduit 82 when the pilot relief valve is opened,
  • Control chamber 104 is provided to supply the operating force to move piston 96- to the left.
  • Control conduit 102 provides fluid communication between conduit 48 and chamber 104, While orifice 106 is positioned in conduit 102 at any convenient location to control the rate of fluid flow into chamber 104.
  • Control chamber 104 is in turn in fluid communication with conduit 58.
  • FIGURE 3 relates to another embodiment of the invention of FIGURES l and 2 and shows a schematic wiring diagram of the electrical control system for operating the relief valve 62 responsive to the position of boom 12.
  • Adjustable linkage 118 which may be of the cam type as shown in FIG. 1, interconnects boom arm 12 with on-off switch 112. The linkage 118 may be adjusted to vary the position at which the boom 12 will throw switch 112.
  • Electrical supply source 116 is connected to ground by line 128 and through line 126 to manually operated on-oif switch 114.
  • Switch 114 is connected through line 124 to switch 112 which is in turn connected through line 122 to solenoid 110 and then to ground through line 120.
  • Solenoid 110 operates relief valve 62 which interconnects conduits 58 and 60.
  • unloading valve 36 may desirably operate to give combined flow from both pumps when the resistance in line 48 has built up to 250 psi. It has also been found expedient to construct cam follower 64 so that its length may be adjusted so that relief valve 62 operates when bucket 14 moves past a desired distance from the ground within the range of O to 4 feet, as an example.
  • pilotrelief valve 86 is provided. In the preferred embodiment previously described pilot relief valve 86 will operate to unload pump 24 when pressure in line 48 reaches 2000 psi. This pressure is transmitted through conduit 72 into pilot relief line 82 and the pressure then overcomes the biasing force of spring 88 to open relief valve 86.
  • pilot relief bleed line 92 is also provided to give fluid communication between pilot relief chamber 84 and the central portion of chamber 74. This is provided so that any fluid remaining in chamber 84 or in the space between piston head 98 and the left end of chamber 74 will not prevent movement of piston 96 to the left position but instead will drain through pilot relief bleed line 92 into chamber 74.
  • Orifice 94 is provided in pilot relief bleed line 92 so that pressure may build up to a sufiicient value to act against piston head 98 when the pilot relief valve operates. It is understood that spring 88 which urges pilot relief valve 86 to its closed position may be selected to allow the pilot relief valve 86 to open at any desired pressure, depending upon the operating characteristics desired in the vehicle.
  • FIGURE 3 describes another embodiment of this invention wherein an electrical circuit is provided to operate relief valve 62.
  • solenoid directly operates relief valve 62 to the open or closed position.
  • Operation of solenoid 110 is in turn controlled by the position of boom arm 12 so that relief valve 62 is opened and closed in relation to the position of boom arm 12 in a similar manner to that described in connec tion with FIGURE 1.
  • Linkage 1*18 connecting boom arm 12 to switch 112 may be of any well known adjustable linkage such as a cam with a cam follower of adjustable length. Assuming that the operator has closed switch 114, with boom 12 in the low position linkage 118 will have closed switch 112.
  • a tractor loader having a pivotal boom
  • the combination comprising hydraulic motor means for pivoting said boom, a load-engaging attachment mounted on said boom, afirst source of fluid pressure connected with said motor means, :a second source of fluid pressure adapted for connection with said motor means, said second source being normally disconnected from said motor means, valve means responsive to a first resistance of said load for connecting said second source with said motor means and responsive to a second resistance of said load greater than said first resistance for disconnecting said second source from said motor means.
  • valve means is responsive to a first predetermined 7 pressure in said motor means for connecting said second source with said motor means and to a second predetermined pressure in said motor means higher than said firstpressure for disconnecting said second source from said motor means.
  • connection between the first source and said motor means comprises a conduit
  • said valve means including pressure responsive piston means movable between a first position disconnecting said second source from said motor means and a second position connecting said second source to said motor means, said valve means being responsive to a first predetermined pressure in said conduit for moving said piston to said second position
  • a tractor loader having pivotal boom
  • the combination comprising hydraulic motor means for pivoting said boom, a load-engaging attachment mounted on said boom, a first source of fluid pressure connected with said motor means, a second source of fluid pressure, valve means responsive to a first resistance of said load for connecting said second source with said motor means and responsive to a second resistance of said load for disconnecting said second source from said motor means, and operating means for selectively preventing said valve means from connecting said second source with said motor means, said operating means being responsive to a first pivot angle of said boom for preventing said valve means from connecting said second source with said motor means.
  • a tractor loader having a pivotal boom
  • the com- :bination comprising hydraulic motor means for pivoting said boom, a load-engaging attachment mounted on said boom, a first source of fluid pressure connected with said motor means, a second source of fluid pressure,'valve means responsive to a first resistance of said load for connecting said second source with said motor means and responsive to a second resistance of said load for disconnecting said second source from said motor means, said connection between the first source and said motor ,means comprising a conduit
  • said valve means including pressure responsive piston means movable between a first position disconnecting said second source from said motor means and a second position connecting said second source to said motor means, said valve means being responsive to a first predetermined pressure in said conduit for moving said piston to said second position and responsive to a second predetermined pressure in said conduit for moving said piston to said first position, other means for preventing movement of said piston to said second position, and additional means connected with said boom for operating said other means in response to a predetermined position of said boom.
  • a tractor loader having a pivotal boom
  • the combination comprising hydraulic motor means for pivoting said boom, a load-engaging attachment mounted means and responsive to a second resistance of said load for disconnecting said second source from said motor means, said'connection between the first source and said line.
  • valve means including pressure responsive piston means movable between a first position disconnecting said second source from said motor means and a second positionconnecting said second source to said motor means, said valve means being responsive to a first predetermined pressure in said conduit for moving said piston to said second position and responsive to a second predetermined pressure in said conduit for moving said piston to said first position, other means for preventing movement of said piston-to said second position, a source of electrical power, solenoid means for operating said other means, switch means for connecting said source of power to said solenoid means, and linkage means for operating said switch means in response to a predetermined position of said boom.
  • a tractor loader having a pivotal boom supporting a movable bucket
  • the combination comprising hydraulic motor means, a first pump supplying fluid at'a selected pressure, a second pump supplying fluid at a pressure lower than said selected pressure, a first conduit connecting said first pump to said hydraulic motor means, an unloading valve with a first chamber connecting the pressure side of said second pump to said first conduit, 21 second conduit connecting said first chamber to a hydraulic reservoir, a piston slidable in said chamber to first and second positions, biasing means urging said piston to said first position, said piston opening said second conduit in said first position and closing said second circuit in said second position, a second chamber, a third conduit connecting said first conduit with said second chamber, said piston slidable in said second chamber and adapted to move to said second position when a first predetermined pressure is present in said second chamber, a third chamber, valve means connecting said conduit with said third chamber for admitting fluid into said third chamber at a second predetermined pressure in said conduit, said piston slidable insaid third chamber and adapted
  • said relief valve means includes a relief conduit connected to said second chamber for closing said relief conduit in a closed position and connecting said relief conduit with said reservoir in an open position.
  • a tractor loader having a boom carrying a hydraulically operated loadingattachment, hydraulic operating means for operating said attachment in a first speed, and a second speed higher than said first speed, selector means connected with said operating means for selecting one of said speeds, and control means for selectively'preventing said selector means from changing from the first speed to the second speed.
  • a tractor loader having a boom carrying a hydraulically operated loading attachment, hydraulic operating means for operating said attachment in at least two speeds, selector means connected with said operating means for selecting one of said speeds, control means for selectively preventing said selector means from changing to the other of said speeds, said control means being responsive to the position of said boom.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Mining & Mineral Resources (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Operation Control Of Excavators (AREA)
  • Fluid-Pressure Circuits (AREA)
US420681A 1964-12-23 1964-12-23 Hydraulic control system for tractor loader Expired - Lifetime US3250411A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
US420681A US3250411A (en) 1964-12-23 1964-12-23 Hydraulic control system for tractor loader
GB51179/65A GB1133955A (en) 1964-12-23 1965-12-02 Improvements in or relating to a tractor-mountable loader
DE19651634816D DE1634816B1 (de) 1964-12-23 1965-12-21 Hydraulisches Steuersystem fuer Schaufelbagger
FR43232A FR1464266A (fr) 1964-12-23 1965-12-21 Installation de commande hydraulique

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US420681A US3250411A (en) 1964-12-23 1964-12-23 Hydraulic control system for tractor loader

Publications (1)

Publication Number Publication Date
US3250411A true US3250411A (en) 1966-05-10

Family

ID=23667439

Family Applications (1)

Application Number Title Priority Date Filing Date
US420681A Expired - Lifetime US3250411A (en) 1964-12-23 1964-12-23 Hydraulic control system for tractor loader

Country Status (4)

Country Link
US (1) US3250411A (fr)
DE (1) DE1634816B1 (fr)
FR (1) FR1464266A (fr)
GB (1) GB1133955A (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0092315A2 (fr) * 1982-04-15 1983-10-26 Automotive Products Public Limited Company Commande hydraulique de pompes
US20100038565A1 (en) * 2008-08-12 2010-02-18 Honeywell International Inc. Propellant gas control valve

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3095990A (en) * 1961-03-30 1963-07-02 Hough Co Frank Transmission controlled loader hydraulic circuit
US3108701A (en) * 1962-03-08 1963-10-29 New York Air Brake Co Hydrostatic transmission

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3095990A (en) * 1961-03-30 1963-07-02 Hough Co Frank Transmission controlled loader hydraulic circuit
US3108701A (en) * 1962-03-08 1963-10-29 New York Air Brake Co Hydrostatic transmission

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0092315A2 (fr) * 1982-04-15 1983-10-26 Automotive Products Public Limited Company Commande hydraulique de pompes
EP0092315A3 (fr) * 1982-04-15 1984-07-18 Automotive Products Public Limited Company Commande hydraulique de pompes
US20100038565A1 (en) * 2008-08-12 2010-02-18 Honeywell International Inc. Propellant gas control valve
US8312705B2 (en) * 2008-08-12 2012-11-20 Honeywell International Inc. Propellant gas control valve

Also Published As

Publication number Publication date
GB1133955A (en) 1968-11-20
FR1464266A (fr) 1966-12-30
DE1634816B1 (de) 1971-10-28

Similar Documents

Publication Publication Date Title
US4359931A (en) Regenerative and anticavitation hydraulic system for an excavator
US3563137A (en) Hydraulic self-leveling control for boom and bucket
US4078681A (en) Dual pump hydraulic control system with predetermined flow crossover provision
EP1662151B1 (fr) Dispositif a commande hydraulique
US3339763A (en) Automatic back hoe control system
US6370874B1 (en) Hydraulic control device for a mobile machine, especially for a wheel loader
US3472127A (en) Control circuit for bulldozers used in pushing
GB2514112A (en) Valve Arrangement
US7434394B2 (en) Hydraulic drive device
US4126083A (en) Attitude control for implement
EP1541872B1 (fr) Entrainement hydraulique
US3630121A (en) Excavating machines
US3262467A (en) Spool valve with cavitation-minimizing valve assembly
KR950002980B1 (ko) 유압 회로
US2782946A (en) Power loaders
US4218837A (en) High lift hydraulic system for an excavator
US3250411A (en) Hydraulic control system for tractor loader
US3181430A (en) Relief valve for bucket loader circuits
US6612109B2 (en) Hydraulic power boost system for a work vehicle
US3519155A (en) Bucket positioning device
US3122247A (en) Automatic positioning device for material handling bucket
US3494495A (en) Tractor mounted loader
US3997007A (en) Implement positioning hydraulic control system
US2887990A (en) Lift cylinder regulator valve
US3792792A (en) Hydraulic self-leveling device for a loader bucket

Legal Events

Date Code Title Description
AS Assignment

Owner name: DRESSER INDUSTRIES, INC., A CORP. OF DEL.

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:INTERNATIONAL HARVESTER COMPANY;REEL/FRAME:004130/0646

Effective date: 19821101

Owner name: DRESSER INDUSTRIES, INC., A CORP. OF DEL., STATELE

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:INTERNATIONAL HARVESTER COMPANY;REEL/FRAME:004130/0646

Effective date: 19821101