US3715014A - Industrial truck - Google Patents

Industrial truck Download PDF

Info

Publication number
US3715014A
US3715014A US00124781A US3715014DA US3715014A US 3715014 A US3715014 A US 3715014A US 00124781 A US00124781 A US 00124781A US 3715014D A US3715014D A US 3715014DA US 3715014 A US3715014 A US 3715014A
Authority
US
United States
Prior art keywords
mast
ram
chain
cylinder
outer cylinder
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
US00124781A
Other languages
English (en)
Inventor
S Ohta
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.)
Toyota Industries Corp
Original Assignee
Toyoda Automatic Loom Works Ltd
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 Toyoda Automatic Loom Works Ltd filed Critical Toyoda Automatic Loom Works Ltd
Application granted granted Critical
Publication of US3715014A publication Critical patent/US3715014A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
    • B66F9/00—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes
    • B66F9/06—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes movable, with their loads, on wheels or the like, e.g. fork-lift trucks
    • B66F9/075—Constructional features or details
    • B66F9/08—Masts; Guides; Chains

Definitions

  • An industrial truck of the type of so-called full free triple stage uprights or masts comprising an outer mast, an intermediate mast vertically movable relative to said outer mast, an inner mast vertically movable relative to said intermediate mast, a load carriage vertically movable relative to said inner mast, a second ram connected with said inner mast, an inner cylinder concentrically arranged within said second ram, a first ram engaging concentrically with the outer side of said second ram, an outer cylinder concentrically engaging with the outer side of said first ram, chain wheels rotatably supported by said outer cylinder, and intermediate mast and said load carriage respectively, a chain of which one end and other end being mounted on said outer mast and said inner mast respectively and guided by said chain wheel at said intermediate mast, and a chain connected at one end with said outer cylinder and at the other end with said inner mast after passing over said chain wheels at said load carriage and at said outer cylinder.
  • This invention relates to an industrial truck or fork lift, particularly provided with so-called full free triple stage uprights or masts.
  • a fork lift with triple stage uprights usually there is an intermediate upright adapted for telescopic vertical movement relative to an outer upright which is rigidly mounted to the truck frame, and the inner upright adapted for telescopic movement relative to said intermediate upright, said inner upright being lifted by means of an oil cylinder.
  • a chain wheel mounted on the upper part of said oil cylinder is lifted thereby and the lift bracket and the fork guided by the inner upright are also lifted by means of the oil cylinder.
  • the oil cylinder proper as a whole is adapted for vertical movement relative to each upright, so that it is necessary to provide a latch device for connecting the upper end of the oil cylinder with the upper end of the inner upright when the inner upright is elevated in order to allow the downward movement of the inner upright according to the total weight of the inner upright, the oil cylinder, the lift bracket, the fork and the load.
  • a latch device for connecting the upper end of the oil cylinder with the upper end of the inner upright when the inner upright is elevated in order to allow the downward movement of the inner upright according to the total weight of the inner upright, the oil cylinder, the lift bracket, the fork and the load.
  • the inner upright will be suddenly dropped due to its weight, so that it impinges the upper end of the oil cylinder which is in the dropped position.
  • Such sudden dropping of the oil cylinder and succeeding shock of the upper end of the oil cylinder will be very noisy, annoying the operator.
  • the provision of the latch device is not only expensive, but also results in a complex structure of the fork lift. Furthermore, accidental failure of the operation of the latch is unavoidable. Therefore, it would of course be most desirable to have a fork lift not provided such a latch device.
  • the principal object of the present invention is to provide an industrial truck with full free triple stage uprights, in which the operators front field of vision is wider.
  • Another object of the present invention is to provide a new industrial truck or fork lift with so-called full free triple stage uprights which is adapted for smooth operation without providing any latch device.
  • a still further object of the present invention is to provide an industrial truck of full free triple stage uprights of simple construction where the upper and lower ends of the oil cylinder may be rigidly mounted on the mast.
  • FIGS. 1 to 4 show side views of the masts or uprights of the industrial truck according to one embodiment of the present invention;
  • FIG. 1 showing an oil cylinder for lifting the fork in its retracted position;
  • FIG. 2 showing said oil cylinder in its first elongated position;
  • FIG. 3 showing said oil cylinder in its second elongated position;
  • FIG. 4 showing said oil cylinder in its third elongated position.
  • FIG. 5 shows one embodiment of said triple stage liftable oil cylinder.
  • the reference numeral 1 designates an outer upright or mast mounted to the truck frame (not shown), and 2 designates an intermediate upright or mast vertically movable relative to said outer mast 1.
  • 3 designates an inner upright or mast vertically movable up and down relative to said intermediate mast 2.
  • 4 designates a lift bracket vertically movable relative to said inner upright 3.
  • the lift bracket 4, the inner mast 3 and the intermediate mast 2 are adapted to be vertically movable by means of the oil cylinder 5, the chains 10, 14 and the chain wheels 11, 12 and 13.
  • the chain wheel 13 is rotatably mounted adjacent the lower end of the intermediate mast 2, and both ends thereof are adapted for guiding the chain 14, of which both ends are rigidly mounted to the outer mast 1 and the inner mast 3.
  • the oil cylinder 5 consists of the outer cylinder 9, the first ram 8, the second ram 7 and the inner cylinder 6, which are concentrically arranged.
  • the lower end of the inner cylinder 6 is connected with the lower end of the intermediate mast 2 by means of the lower connector 2A, and the chain wheel 11 is rotatably mounted to the upper end of the outer cylinder 9.
  • One end of the chain 10 is connected with the mid point of the chain wheeel 11 or with the outer cylinder 9 and the other end extends down around a chain wheel 12 rotatably mounted on the lift bracket 4 and then over the chain wheel 11 mounted to the inner mast 3.
  • seal member 8A sliding along the inner surface of the outer cylinder 9 is provided.
  • a seal member 9A is mounted to the upper end of the outer cylinder 9, which seal member 9A is adapted together with said seal member 8A for sealing the space between the outer cylinder 9 and the first ram 8.
  • seal member 7A sliding along the inner surface of the first ram 8. Said seal member 7A, together With the seal member 8B mounted on the upper end of the first ram 8 are adapted for sealing the space between the first ram 8 and the second ram 7.
  • a sliding member 6A sliding along the innersurface of the second ram 7, and by means of sealing member 7B mounted at the lower end portion of the second ram 7, thereby sealing the space between the second ram 7 and the inner cylinder 6.
  • the first ram and the second ram, and the inner cylinder are provided with oil ducts 8C, 7C and 6C respectively.
  • d D d D D show the inner diameter of the outer cylinder 9, the outer diameter of the first ram 8, and the inner diameter of the latter, the outer diameter of the second ram 7 and the outer diameter of the inner cylinder 6, respectively.
  • the upper end of the outer cylinder 9 will lift the upper connecting element 3A of the inner mast 3 through the upper flange SD of the first ram 8.
  • the second ram 7 and the inner mast 3 will also be lifted, so the the inner cylinder 6 and the intermediate mast 2 for the stroke 1 through the sliding member 6A of the inner cylinder 6 will abut against the seal member 7B reaching to the state shown in FIG. 4.
  • the inner mast 3 and the outer cylinder 9 will be lifted together, so that there will not be any relative movement between the inner mast 3 and the chain wheel 11, between which both ends of the chain are mounted.
  • the lift bracket and the fork 4 will be lifted for length of 1 relative to the inner cylinder 6 and the intermediate mast 2. Further, the intermediate mast 2 will be lifted for length l relative to the outer mast 1, so that during the period of changing from the state of FIG. 3 to the state of FIG. 4, the lift bracket and the fork 4 will be lifted for the length of 21 in total. Further, if the total lift l/ 2+l/ 2:1 between FIG. 1 and FIG. 3 is added thereto, it results in that the lift bracket and the fork 4 are lifted for the length of 31 during movement effected between FIG. 1 and FIG. 4.
  • the upper end of the oil cylinder 6 is rigidly mounted on the upper end of the inner mast 3, while its lower end is rigidly mounted to the lower end of the intermediate mast 2. It is thus designed employing no latch device, so that it is not only safe in operation, but also is inexpensive to manufacture.
  • the height of the outer cylinder 9, the chain wheel 11 and the chain 10 will be lower (half or less) than the front field of view of the operator.
  • an industrial lift truck having multistage uprights or masts, the improvement comprising an outer mast; an intermediate mast vertically movable relative to said outer mast; an inner mast vertically movable relative to said outer and intermediate masts; a load carriage carried by said inner mast and vertically movable relative thereto; a second ram connected to the upper end of said inner mast; an inner cylinder concentrically arranged within said second ram and connected with the lower end of said intermediate mast, said second ram and said inner cylinder having substantially the same length as said'inner mast; a first ram concentrically arranged about theouter side of said second ram; an outer cylinder concentrically arranged about the outer side of said first ram, said first ram having a length substantially equal to two-thirds the length of said inner mast and said outer cylinder having a length substantially equal to one-third the length of said inner mast; first, second and third chain wheels rotatably supported by said intermediate mast, said outer cylinder and said load carriage, respectively; a first chain having one end thereof connected to

Landscapes

  • Engineering & Computer Science (AREA)
  • Transportation (AREA)
  • Structural Engineering (AREA)
  • Civil Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Mechanical Engineering (AREA)
  • Forklifts And Lifting Vehicles (AREA)
US00124781A 1970-03-18 1971-03-16 Industrial truck Expired - Lifetime US3715014A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP45023257A JPS4917188B1 (enExample) 1970-03-18 1970-03-18

Publications (1)

Publication Number Publication Date
US3715014A true US3715014A (en) 1973-02-06

Family

ID=12105534

Family Applications (1)

Application Number Title Priority Date Filing Date
US00124781A Expired - Lifetime US3715014A (en) 1970-03-18 1971-03-16 Industrial truck

Country Status (2)

Country Link
US (1) US3715014A (enExample)
JP (1) JPS4917188B1 (enExample)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3845866A (en) * 1972-09-28 1974-11-05 Gottwald Kg Leo Telescopic crane jib
US4051970A (en) * 1975-11-07 1977-10-04 K-D Manufacturing Company Lift truck load handling mast
US4496031A (en) * 1979-04-18 1985-01-29 The Raymond Corporation Material handling apparatus
US4848520A (en) * 1986-12-22 1989-07-18 Carelift Equipment Limited Telescopic mast assembly
US5248022A (en) * 1990-11-28 1993-09-28 Tokyo Electron Limited Driving device having sealing mechanism

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3845866A (en) * 1972-09-28 1974-11-05 Gottwald Kg Leo Telescopic crane jib
US4051970A (en) * 1975-11-07 1977-10-04 K-D Manufacturing Company Lift truck load handling mast
US4496031A (en) * 1979-04-18 1985-01-29 The Raymond Corporation Material handling apparatus
US4848520A (en) * 1986-12-22 1989-07-18 Carelift Equipment Limited Telescopic mast assembly
US5248022A (en) * 1990-11-28 1993-09-28 Tokyo Electron Limited Driving device having sealing mechanism

Also Published As

Publication number Publication date
JPS4917188B1 (enExample) 1974-04-27

Similar Documents

Publication Publication Date Title
US3394778A (en) Lift truck mast assembly
US4630855A (en) Lifting yoke for containers
US4191276A (en) High-visibility two-stage mast assembly for lift trucks
US3786902A (en) Load-lifting mechanism for a lift truck
US5992571A (en) Mast assembly for forklift trucks
US3715014A (en) Industrial truck
US4977980A (en) Indirect-plunger hydraulic elevator
US3506092A (en) Lift truck
US3727781A (en) Lift truck load lifting mechanism
US2419938A (en) Truck hoist mechanism
US3651891A (en) Hoist for lift trucks
US3077951A (en) Lift truck mast operation sequence mechanism
US3061045A (en) Friction-free load hoisting mast
US3782503A (en) Mast stabilizer for lift trucks
CA1174205A (en) Triple mast for fork lift trucks
US3235034A (en) Triple lift truck with continuous lift chain
US5284224A (en) Low clearance vehicle lift
US3072219A (en) Free lift cylinder
US4238004A (en) Hidden chain assembly for lift truck mast
US2527384A (en) Hydraulically operated tier-lift mechanism
US3289791A (en) Hydraulic ram for lift truck
US3116812A (en) Lift truck with ram-actuated extensible mast assembly
US4276961A (en) Mast and carriage assembly
US4310072A (en) Fluid line coupling for fluid actuated extensible structure
US3369632A (en) Triple section mast with high free lift