AU766008B2

AU766008B2 - Manipulation levers of forklift and forklift

Info

Publication number: AU766008B2
Application number: AU11963/02A
Authority: AU
Inventors: Kazushi Kamiya; Hiroyuki Kidokoro
Original assignee: Toyota Industries Corp
Current assignee: Toyota Industries Corp
Priority date: 2001-01-23
Filing date: 2002-01-21
Publication date: 2003-10-09
Anticipated expiration: 2022-01-21
Also published as: TW510887B; JP2002220196A; AU1196302A; KR100449371B1; JP4302899B2; CA2368535A1; CA2368535C; KR20020062689A

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicant(s): KABUSHIKI KAISHA TOYOTA JIDOSHOKKI Invention Title: MANIPULATION LEVERS OF FORKLIFT AND FORKLIFT The following statement is a full description of this invention, including the best method of performing it known to me/us: ,4 TITLE OF THE INVENTION Manipulation Levers of Forklift and Forklift BACKGROUND OF THE INVENTION The present invention relates to a manipulation lever of a forklift. Particularly, the present invention pertains to a manipulation lever of a forklift in which an operator stands.

~In a typical reach type battery-powered forklift, in which an operator stands, an operator's cab is located in the vicinity of the rear side of the body frame. An S 15 operator in the operator's cab operates the forklift to move and handle a load. The operator's cab is defined by a side frame, which is on the left side, a front frame, and a guard frame, which is on the right side.

20 Fig. 7 is a partial front view of a reach type :.forklift in which an operator stands. A steering wheel 1 is arranged on a side panel, which is located at the upper oooeo S portion of the side frame. For example, a lift lever 3, a tilt lever 4, and a reach lever 5 are arranged on a front panel 2, which is located at the upper portion of the front frame. The lift lever 3 is used for lifting and lowering a fork. The tilt lever 4 is used for tilting the fork. The reach lever 5 is used for moving masts. A driving lever 6, which is used for moving the body frame, is provided on the right side portion of the front panel 2. The lift lever 3, the tilt lever 4, the reach lever 5, and the driving lever 6 tilt forward and rearward.

An operator 7 handles the steering wheel 1 with the 2 left hand. Meanwhile, the operator 7 handles the lift lever 3, the tilt lever 4, the reach lever 5, and the driving lever 6 with the right hand. In the reach type forklift, the operator 7 is frequently required to handle a load, or particularly, to lift and lower a fork, and to move the body frame at the same time or consecutively. Therefore, the operator 7 handles the lift lever 3, the tilt lever 4, and the reach lever 5 with the right hand while operating the driving lever 6 with the right forearm or the right elbow.

When the operator 7 needs to change the moving direction of the body frame from forward to rearward while lifting or lowering the fork, the operator 7 needs to lift the right arm and grasp the lever 3 again before pressing S 15 the driving lever 6 rearward. Such operation is complicated and decreases efficiency. Further, when handling a load, the above mentioned operation is frequently performed. Thus, go the operator 7 gets more and more tired.

20 Japanese Laid-Open Patent Publication No. 10-236797 discloses a manipulation lever, which is selectively tilted forward, rearward, leftward, and rightward. When the ooooo manipulation lever is tilted forward or rearward, the vehicle moves accordingly. When the manipulation lever is tilted leftward or rightward, a fork is lifted or lowered accordingly.

According to the above mentioned manipulation lever, the direction of the movement of the fork differs from that of the lever. Therefore, an operator feels uncomfortable and takes long time until the operator masters the lever operation.

SUMMARY OF THE INVENTION 3 The objective of the present invention is to provide a manipulation lever that facilitates operation for handling a load and moving the forklift.

To achieve the foregoing objective, the present invention provides a manipulation lever located on the body frame of a forklift. The lever includes a lever body, a grip, and a knob. The lever body is arranged on the body frame to be tilted. The grip is arranged on the lever body.

The shape of the grip is formed to be grasped with a hand S. with the palm facing down. The knob is rotatably arranged S"on the grip. The knob is rotated by selectively moving the knob upward and downward with the thumb of a hand grasping S 15 the grip.

The present invention also provides a forklift that g.has an operator's cab in which an operator stands. The forklift includes a front panel located at the front portion 20 of the operator's cab, a manipulation lever, a first detecting apparatus, a second detecting apparatus, and a controller. The manipulation lever includes a lever body, a S grip, and a knob. The lever body is arranged on the front panel and selectively tilted forward and backward. The grip is arranged on the lever body. The shape of the grip is formed to be grasped with a hand with the palm facing down.

The knob is rotatably arranged on the grip. The knob is rotated by moving the knob upward and downward with the thumb of a hand grasping the grip. The first detecting apparatus detects the inclination direction and the inclination angle of the lever body. The second detecting apparatus is located in the grip. The second detecting apparatus detects the rotation direction and the rotation angle of the knob. The controller controls the base frame 4 to move in the same direction as the inclination direction of the lever body in accordance with the detected value of the first detecting apparatus, and controls a fork to be lifted and lowered in the same direction as the rotating direction of the knob in accordance with the detected value of the second detecting apparatus.

Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.

S" BRIEF DESCRIPTION OF THE DRAWINGS go 15 The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments gotogether with the accompanying drawings in which: Fig. 1 is a partial perspective view illustrating a 20 reach type battery-powered forklift, in which an operator stands, according to a first embodiment of the present invention; ooooo S• Fig. 2 is a perspective view illustrating the manipulation lever provided in the forklift shown in Fig. 1; Fig. 3 is a plan view of the manipulation lever shown in Fig. 2; Fig. 4 is a side view illustrating the manipulation lever taken along line 4-4 shown in Fig. 3; Fig. 5 is a side view illustrating the grip of the manipulation lever taken along line 5-5 shown in Fig. 4; Fig. 6 is a schematic diagram illustrating a control system for moving the fork lift and handling a load in relation to the manipulation lever of the present invention; and Fig. 7 is a partial front view illustrating a prior art reach type battery-powered forklift.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A reach type battery-powered forklift 10 according to a first embodiment of the present invention will now be described with reference to Figs. 1 to 6. Fig. 1 shows a part of an operator's cab 12 of the forklift 10. An :-.-operator 7 stands in the operator's cab 12 of the forklift when operating the forklift 10 to move and handle a load.

*99* The direction that the operator 7 looks at masts 14 S 15 from the operator's cab 12 is referred to as the forward direction. The operator's cab 12 is defined by a front frame 16, a side frame 18, which is on the left side, and a guard frame 20, which is on the right side. The front frame 16 is provided on the front side of the body frame to cover, 20 for example, a controller and an oil control valve for 999* [[handling a load. The side frame 18 covers, for example, a drive apparatus and a steering apparatus. An opening 22 is S provided between the rear end of the guard frame 20 and the S"side frame 18 for the operator 7 to step on and off the operator's cab 12. A waist supporter 24 for supporting the waist of the operator 7 is arranged on the upper inner surface of the curved portion of the guard frame A steering wheel 28 is arranged on a panel 26, which is located at the upper portion of the side frame 18. A manipulation lever 32 is arranged on a front panel 30, which is located at the upper portion of the front frame 16. A wrist supporter 34 protrudes from the front panel 30 for supporting the right forearm and the right elbow of the operator 7.

Figs. 2 to 5 are detailed illustrations of the manipulation lever 32. As shown in Fig. 4, the manipulation lever 32 includes a lever body 36, which is rotatably arranged on the front frame 16. The lever body 36 extends upward through a slot 38, which is formed on the front panel The slot 38 extends in the forward and rearward direction of the body frame. The lever body 36 is selectively tilted forward and rearward along the slot 38.

The lower end (not shown) of the lever body 36 is connected to an input shaft of a first potentiometer 40 (a first detecting apparatus) for detecting the inclination angle and the inclination direction of the lever body 36. As shown in ooro• S 15 a schematic diagram of Fig. 6, a detected value of the first potentiometer 40 is sent to a controller 42, which is a microcomputer. The controller 42 controls a drive apparatus 44 in accordance with the detected value so that the body frame moves in accordance with the inclination of the lever 20 body 36. The inclination direction of the lever body 36 is *the same as the direction that the base frame is moved. A spring (not shown) is arranged between the lever body 36 and I the input shaft of the first potentiometer 40. The lever body 36 is retained in a neutral position, which is substantially vertical, by the force of the spring when the lever body 36 is not used.

As shown in Figs. 2 to 4, the manipulation lever 32 includes a grip 46, which is arranged on the upper end of the lever body 36. The grip 46 preferably includes two separate grip pieces 46a, 46b (see Fig. which are made of synthetic resin. The upper end of the lever body 36 is arranged between the grip pieces 46a, 46b. The grip pieces 46a, 46b are secured to each other with bolts and nuts and fixed on the lever body 36. The grip 46 extends along an axis L in a bar-like shape, the shape of the grip 46 being formed to be grasped with a hand with the palm facing down.

The operator 7 grasps the grip 46 with the right hand with the palm facing down. The operator 7 grasps the grip 46 mainly with the third finger and the little finger.

Therefore, a right side portion 48 of the grip 46, which is held by the third finger and the little finger, has narrow width in the direction that is perpendicular to the axis L.

A left side portion 50 of the other end of the grip 46 has broad width. The operator 7 puts the forefinger and the 0 middle finger on the upper surface of the left side portion *090 50. A back surface portion 52 extends substantially vertically from the base portion of the grip 46, or the 15 joint portion with the lever body 36. The operator 7 puts the base of the thumb (ball of the thumb) of the right hand on the back surface portion 52.

oio So The operator 7 puts the right forearm and the right 20 elbow on the wrist supporter 34 and places the right forearm in the left and right direction. That is, the operator 7 grasps the grip 46, such that the right forearm is parallel dote*: S° with a horizontal X-axis, which extends in the width a direction of the base frame. Therefore, the grip 46 is arranged on the lever body 36 in a way to permit the operator 7 to easily grasp the grip 46. That is, as shown in Fig. 3, the axis L of the grip 46 is inclined counterclockwise by an angle a, which is 30 to 60 degrees, with respect to the X-axis as viewed from right above. For the similar reason, when the lever body 36 is at the neutral position, the axis L of the grip 46 is vertically inclined with respect to the X-axis (see Fig. 4) A substantially cylindrical knob 54 is arranged on the 8 left end of the grip 46 and rotates about the axis L, so that the knob 54 can be rotated by selectively moving the knob upward and downward with the thumb of a hand grasping the grip. The knob 54 is secured to the input shaft of a second detecting apparatus, which is a second potentiometer 58 in this embodiment. The second potentiometer 58 is embodied in the grip 46 with, for example, screws. More preferably, the knob 54 is secured to an input shaft of the decelerator (not shown), which is connected to the input 10 shaft of the second potentiometer 58, with, for example, screws. A protrusion 56 extends along the axis L on the outer circumferential surface of the knob 54. The operator 7 easily turns the knob 54 by pressing the protrusion 56 upward or downward with the thumb of the right hand, which is grasping the grip 46. As shown in the schematic diagram of Fig. 6, the second potentiometer 58, which is connected S"to the knob 54, detects the rotation direction and the rotation angle of the knob 54 and sends the detected value to the controller 42. In the preferred embodiment, the 20 controller 42 controls a first oil control valve 62, which is connected to a lift cylinder 60, in accordance with the detected value sent from the second potentiometer 58 and lifts or lowers a fork (not shown) along the masts 14. Thus, the fork of the forklift is selectively lifted and lowered in accordance with the rotation of the knob 54. The protrusion moves in accordance with the movement of the thumb, and the moving direction of the protrusion is the same as the direction that the fork is selectively lifted and lowered. The knob 54 is retained in a neutral position by a spring (not shown), which is embedded in the decelerator, when the knob 54 is not used. The term "knob" includes means to rotate axis such as a lever.

Switching means for reaching masts, which is a seesaw 9 switch 64 in this embodiment, is arranged on the left side portion 50 of the grip 46. The seesaw switch 64 (or reach switch) is arranged at a suitable place and in a suitable direction for the operator 7 to operate mainly with the forefinger of the right hand. One of the ends of the seesaw switch 64 is located toward the front side of the base frame and the other end is located toward the rear side of the body frame. The seesaw switch 64 controls the forward and rearward movement of the masts 14. The seesaw switch 64 is 10 connected to the controller 42. The controller 42 controls a second oil control valve 68, which is connected to a reach cylinder 66, in accordance with the output signal sent from the seesaw switch.

A cruciform button 70 is located on the back surface portion 52 of the grip 46. The cruciform button 70 is ""arranged at a position such that the operator 7 presses with the thumb of the right hand, which is grasping the grip 46.

The cruciform button 70 includes an upper end portion (first *o *o 20 end portion) 70a, a lower end portion (second end portion) a right side portion (third end portion) 70c, and a left side portion (fourth end portion) 70d. The upper end portion 70a and the lower end portion 70b of the cruciform button 70 form tilt switching means for controlling the inclination of the masts 14 in the forward and rearward direction. As shown in Fig. 6, the controller 42 controls a third oil control valve 74 of a tilt cylinder 72 in accordance with the signal sent from the cruciform button when the operator 7 presses the upper end portion 70a or the lower end portion 70b. The mast 14 of the forklift is selectively tilted forward and backward in accordance with the operation of the tilt switch, and the operation direction of the tilt switch is the same as the inclination direction of the mast 14.

A side shift attachment (not shown), which is one of options of attachments for handling a load, is attached to the forklift 10. The side shift attachment includes a side shift cylinder 76, which is arranged on a lift bracket for moving the fork left and right. The right side portion and the left side portion 70d of the cruciform button correspond to the side shift attachment. The controller 42 controls a fourth oil control valve 78, which is connected to the side shift cylinder 76, in accordance with a signal :sent from the cruciform button 70 when the operator 7 presses the right side portion 70c or the left side portion 0 oooo A horn button 80 shown in Figs. 3 and 5 is arranged on the front face of the left side portion 50 of the grip 46.

The horn button 80 is mainly pressed by the middle finger.

The operations for moving the forklift and handling a ooooo 20 load using the manipulation lever 32 are described below.

The operator 7 basically stands in a posture as shown .by a dotted line in Fig. i. Specifically, the operator 7 stands in the operator's cab 12, rests the waist against the waist supporter 24 on the guard frame 20, grasps the steering wheel 28 with the left hand, and grasps the grip 46 of the manipulation lever 32 with the right hand. In this state, the operator 7 rests the right elbow and the right forearm near the right elbow on the wrist supporter 34, which is located on the front panel 30. This keeps the right hand, which grasps the grip 46 and the right forearm substantially horizontal, thus reducing exhaustion of the right arm. Furthermore, since the body is supported at two positions, that is, by the waist supporter 24 and the wrist 11 supporter 34, the body is stabilized. Also the posture of the right arm is similar to the driving posture used in the prior art reach type forklift shown in Fig. 7. Therefore, even if the operator 7 is used to the prior art forklift, the operator 7 easily operates the forklift 10, which has the manipulation lever 32 according to the preferred embodiment.

When the operator 7 moves the right forearm forward using the right elbow as a fulcrum, the lever body 36 and the grip 46 of the manipulation lever 32 are tilted forward.

At this time, the first potentiometer 40 detects the inclination direction and the inclination angle of the lever body 36 and sends the detected value to the controller 42.

As a result, the controller 42 controls the drive apparatus 44 and advances the forklift 10 at a speed corresponding to the inclination angle of the manipulation lever 32.

When the operator 7 tilts the manipulation lever 32 20 forward, the right hand could slip off the grip 46.

Therefore, as shown in Figs. 2 to 5, a flange 82 is S* preferably formed on the right end of the grip 46 to prevent slipping of the hand. The flange 82 extends in a direction that intersects the axis L of the grip 46. When the operator 7 moves the right forearm rearward using the right elbow as a fulcrum, the lever body 36 is tilted rearward.

Then, the forklift 10 moves rearward at a desired speed corresponding to the inclination direction and the inclination angle of the lever body 36.

While grasping the grip 46, the manipulation lever 32 is tilted, or the operation for moving the forklift is performed, and the knob 54 is operated with the thumb, subsequently. For example, when the protrusion 56 of the knob 54 is moved upward with the thumb, the controller 42 controls the first oil control valve 62 in accordance with the output signal from the second potentiometer 58. The first oil control valve 62 is controlled such that hydraulic oil is supplied to the lift cylinder 60. Accordingly, the fork is lifted. On the other hand, when the protrusion 56 of the knob 54 is moved downward, the controller 42 switches the position of the first oil control valve 62. The hydraulic oil in the lift cylinder 60 is returned to the oil tank 84. Thus, the fork is lowered.

When the operator 7 exerts an upward force on the knob 54 with the thumb, the fork is lifted. When the operator 7 exerts a downward force on the knob 54 with the thumb, the fork is lowered. Therefore, the direction of movement of the knob 54 is the same as the direction of the actual movement of the fork. Thus, the operator 7 performs the operation for lifting the fork without feeling uncomfortable.

20 While the operator 7 grasps the grip 46, the operation for moving the forklift or the operation for lifting the fork is performed and the seesaw switch 64 for reaching the fork is operated with the forefinger consecutively. When the operator 7 presses the front side end portion of the seesaw switch 64, the controller 42 controls the second oil control valve 68 in accordance with the output signal from the seesaw switch 64. Then, a piston rod of the reach cylinder 66 is extended. As a result, the masts 14 move forward. When the operator 7 presses the rear side end portion of the seesaw switch 64, the masts 14 move rearward.

Therefore, the direction of switching operation and the actual movement of the masts 14 are the same. Thus, the operator 7 easily operates the forklift.

13 When the upper end portion 70a is pressed, the masts 14 are inclined forward. When the lower end portion 70b is pressed, the masts 14 are inclined rearward. When the right side portion 70c is pressed, the fork moves rightward. When the left side portion 70d is pressed, the fork moves leftward. Therefore, the operator 7 performs the operation for tilting the masts 14 and the operation for side-shifting the fork using the cruciform button 70 without feeling uncomfortable. While moving the forklift or handling a load, the operator 7 presses the horn button 80 with the middle finger to sound the alarm.

It should be apparent to those skilled in the art that .the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. Particularly, it should be understood that the invention may be embodied in the following forms.

In the forklift, in which an operator stands, the 20 operation for moving the forklift and the operation for lifting and lowering the fork are often performed consecutively. Therefore, the manipulation lever may be S. designed such that only the lever body inclines and the knob rotates. A manipulation lever, which is designed for each operation, that is, the operation for reaching the fork, the operation for tilting the masts, and the operation for sideshifting the fork, may be provided separately.

In the preferred embodiment, the manipulation lever 32 of the present invention is applied to the forklift, in which an operator stands. However, the manipulation lever 32 may be applied to a counter-balance type forklift. In this case, the fork is lifted or lowered in accordance with the upward or downward rotation of the knob, and the masts are tilted in accordance with the forward or backward inclination of the lever body.

The manipulation lever 32 of the present invention is applied to a forklift in which masts and a fork are integrally tilted, however, the manipulation lever 32 may be applied to a forklift in which only a fork is tilted.

Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalence of the S"appended claims.

For the purposes of this specification it will be clearly understood that the word "comprising" means "including but not limited to", and that the word "comprises" has a corresponding meaning.

It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.

Claims

2. The manipulation lever according to claim i, characterized in that the lever body is selectively tilted forward and backward of the body frame, and wherein the body frame moves in accordance with the inclination of the lever body. .oooo: S
3. The manipulation lever according to claim 2, characterized in that the inclination direction of the lever body is the same as the direction that the base frame is moved.
4. The manipulation lever according to one of claims 1 to 3, characterized in that a fork of the forklift is selectively lifted and lowered in accordance with the rotation of the knob. The manipulation lever according to claim 4, characterized in that the knob includes a protrusion, which moves in accordance with the movement of the thumb, wherein the moving direction of the protrusion is the same as the direction that the fork is selectively lifted and lowered.
6. The manipulation lever according to one of claims 1 to 5, characterized in that the grip includes a tilt switch, wherein a mast of the forklift is selectively tilted forward and backward in accordance with the operation of the tilt switch, and wherein the operation direction of the tilt switch is the same as the inclination direction of the mast. 10 7. The manipulation lever according to one of claims a 1 to 5, characterized in that the grip includes a tilt switch, wherein a fork of the forklift is selectively tilted forward and backward in accordance with the operation of the tilt switch, and wherein the operation direction of the tilt switch is the same as the inclination direction of the fork.
8. The manipulation lever according to one of claims 1 to 7, characterized in that the forklift is reach type, and a reach switch is located on the grip, wherein the reach 20 switch is operated with the finger of a hand grasping the grip, and a mast of the forklift is selectively moved **jforward and backward in accordance with the operation of the reach switch, and wherein the operation direction of the reach switch corresponds to the moving direction of the mast.
9. The manipulation lever according to one of claims 1 to 8, characterized in that the axis of the grip is inclined by 30 to 60 degrees to a horizontal axis that extends in the width direction of the body frame as viewed from right above. The manipulation lever according to one of claims 1 to 9, characterized in that the axis of the grip is inclined on the vertical plane.
11. The manipulation lever according to one of claims 1 to 10, characterized in that a flange is formed on the grip, and the flange extends in a direction that intersects the axis of the grip.
12. A forklift that has an operator's cab in which an operator stands, wherein the forklift includes a front panel located at the front portion of the operator's cab, the 10 forklift characterized by: *OO a manipulation lever, wherein the manipulation lever includes: a lever body, which is arranged on the front panel and selectively tilted forward and backward; a grip, which is arranged on the lever body, wherein the shape of the grip is formed to be grasped with a hand with the palm facing down; and a knob, which is rotatably arranged on the grip, wherein the knob is rotated by moving the knob upward 20 and downward with the thumb of a hand grasping the grip; **ja first detecting apparatus for detecting the inclination direction and the inclination angle of the lever body; a second detecting apparatus located in the grip, wherein the second detecting apparatus detects the rotation direction and the rotation angle of the knob; and a controller, wherein the controller controls the base frame to move in the same direction as the inclination direction of the lever body in accordance with the detected value of the first detecting apparatus, and controls a fork to be lifted and lowered in the same direction as the rotating direction of the knob in accordance with the detected value of the second detecting apparatus. 18
13. The forklift according to claim 12, characterized in that a wrist support is formed on the front panel for resting the forearm or the elbow of a hand grasping the grip.
14. A manipulation lever located in the body frame of a forklift, substantially as hereinbefore described with reference to the accompanying drawings.
15. A forklift, substantially as hereinbefore described with reference to the accompanying drawings. Dated this 15th day of August 2003 KABUSHIKI KAISHA TOYOTA JIDOSHOKKI By their Patent Attorneys GRIFFITH HACK Fellows Institute of Patent and Trade Mark Attorneys of Australia *oo H:\Leanne\Keep\11963-02.doc 15/08/03