GB2256173A

GB2256173A - Transporter with function of maintaining and moving center of gravity.

Info

Publication number: GB2256173A
Application number: GB9211332A
Authority: GB
Inventors: Takashi Nanzai
Original assignee: Tani Denkikogyo Co Ltd
Current assignee: Tani Denkikogyo Co Ltd
Priority date: 1991-05-29
Filing date: 1992-05-28
Publication date: 1992-12-02
Anticipated expiration: 2012-05-28
Also published as: GB9211332D0; KR920021386A; AU1730792A; CA2069821C; CA2069821A1; AU647625B2; JPH04131574U; GB2256173B; KR950003592B1

Abstract

In response to variation of inclination angle of the ground surface over which the transporter is travelling, a drive mechanism 9, 10 is actuated to move a drive arm 1 so as to hold the center of gravity of an object 13, carried by the arm 1, always above a wheel axle 6. The drive mechanism 9, 10, which may be hydraulically, pneumatically or electrically powered, is actuated when the handle 2, by which the transporter is pulled, rotates relative to the transporter body 4 so as to contact either switch 17 or 18. The transporter may be provided with traction means such as an engine. <IMAGE>

Description

TBANSPORTER TITLE FUNCTION OF MAINTAINING AND MOVING CENTER OF GRAVITY The present invention relates to a transporter which enables an operator to carry by himself an object having a heavY weight as far as a predetermined place.

Conventionally. when carrying an object having s weight which is too heavy to lift by oneself, transport work should be carried out by a Plurality of operators, or by a special vehicle such as forklift, truck with crane, etc.

With the prior art transporter. particularly, with the above special vehicle which is used when carrying an object having a weight which ls too heavy to lift by oneself, however, not only the arrangement itself is extremely expensive, but the operator should be highly skilled in operation for smooth execution.

Further, if ground or floor surface of A place on which transport work is carried out is not flat, the object to be put on a carrier should be fixed thereto so as not to slip off therefrom during transport.

What is desired is a transporter having a simple mechanism which enables any operator to safely and easily manipulate same by himself without any specialised operation. technique.

There is provided, according to the present invention, a transporter for carrying on a surface an object having a center of gravity, comprising: first arm means for lifting the object: second arm means for supporting said first arm means; wheel means. rotatably mounted on said second arm means, for enabling movement of the transporter, said wheel'means having an axis: sensor means for sensing a variation of an inclination angle of the surface: and drive means for driving said first arm means, said drive means cooperating with said first arm means to hold the center of gravity of the object always abode said 18 put said wheel means in response to said variation of said inclination angle.

DRTDP DRSCRTPTTON nw THE DRAWINGS Fig. 1 is a perspective view showing a preferred embodiment of a transporter according to the present invention; Fig. 2 is a plan view of the transporter of Fig.

1; Flg. 3 is a front view of the transporter as viewed from the slde of a drag bar; Fig. 4 Is a rear view of the transporter as viewed from the side of rear wheels; Fig. 5 is a side view of the transporter when lifting up an object: Fig. 6 is a view similar to Fig. 5, but after lifting up the object: Fig. 7 is a view similar to Fig. C, but lmmediately before front wheels reach an up incline:: Fig. 8 is a view similar to Fig. 7, but when the transporter is moving on the up incline; Fig. 9 is a view similar to Fig. 8, but immediately before the front wheels reach a down incline; Fig. 10 is a view similar to Fig. 9, but when the transporter is moving on the down incline; Fig. 11 is a view similar to Fig. 1. but showing another embodiment of a transporter, having drive arms with extension mechanism; Fig. 12 is a view similar to Fig. 11, but showing still another embodiment of a transporter, wherein the mounting position of drive shafts and cylinders is changed: and Fig. 13 is a view similar to Fig. 12. but.showing a further embodiment of a transporter having shortened auxiliary arms.

DETAILED DESCRIPTION Referring to the drawings, a preferred embodiment of the present invention will be described, Referring first to Figs. 1-4, a transporter includes a pair of drive arms (first arm means) 1 each arranged on an auxiliary arm (second arm means) 4, and a pair of operation arms 2 each mounted thereto. The operation arms 2 have the other ends connected by a drag bar 3 to which a control part 5 for setting operation mode of the transporter is mounted.

Connected to each drive arm 1 in the upper end portion thereof via a chain 11 is a hook 12 to catch an object 13 (not seen here) to be carried. Inclination of each drive arm 1 is adjustable by a drive shaft 9 (drive means) slideably fitted in a cylinder 10 (drlve means). The transporter is movable by a pair of front wheels 7 (wheel means) with an axle B and a pair of rear wheels 8 rotatably mounted to the auxiliary arms 4, respectively. Up and down switches 17, 18 are arranged on the auxiliary arms 4 at the front end portions thereof, respectively, so as to turn on and off when the operation arms 2 rotate in pressing springs 19. Reinforcing plates 20, 21 are arranged between the auxiliary arms 4.

Next, the operation of this embodiment will be described. Referring particularly to Fig. 5, when lifting up the object 13 to be carried, the transporter is moved so that the object 13 is located between the two auxiliary arms 4. The hook 12 as flxed to the chain 11 at one end thereof is caught to a belt 14 which is put round the object 13. When a lift operation switch is turned on by the control part 5 mounted to the drag rod 3. a motor of a hydraulic pump 23 within the drive arm 1 is rotated so that the drive shaft 9 within the cylinder 10 extends in the direction of the control part 5 by a worm gesr mechanism (not shown), thus rotating the drive arm 1 in the direction of the control part 5.Referring to Fig. 6, the drive arm 1 is automatically stopped when the center of gravity of the object 13 as lifted up comes above the axle 6. Referring also to Fig. 1, movement of the center of gravity of the object 13 is detectable by a level switch 24 mounted within the auxiliary arm 4. This level switch 24 assumes a neutral position when the auxiliary arm 4 is horizontal.

Next, prior to dragging of the transporter.

operation mode of the control part 5 is set to automatic mode. The automatic mode is opposed to socalled manual mode, and corresponds in the present invention to operation mode for driving a drive mechanism of the transporter so as to autoinatically and always hold the center of gravity of the object 13 above the axle 6 in response to variation of an inclination angle of a ground surface 15 on which transport work is carried out. The manual mode corresponds to operation mode wherein an operator operates the drive mechanism of the transporter on his judgement when lifting down the object 13 after its transport to a predetermined place or carrying out fine adjustment of a position of the drive arm 1 which will be described hereinafter.

Referring to Fig. 7, after setting operation mode to automatic mode by the control part 5, if the transporter encounters. for example, an up incline while the operator drags same with the drag rod 3 to carry the object 18, the transporter behaves as follows.

Referring also to Fig. 7, when the operator passes from a flat of the ground surface to the up incline thereof. an operation arm 2 is pivoted upward on A supporting shaft 18 as a fulcrum so that an up switch 17 is turned on by the operation arm 2 on the upper face thereof, thus starting operation of the drive shaft 9 to rotate the drive arm 1 on the side of the drag rod 3.Referring to Fig. 8, the operator continues to go on the up incline, and when a front wheel 7 of the transporter reaches the up incline, the upper face of the operation arm 2 is disengaged from the up switch 17 to turn off same, Accordingly, in case that the transporter is on the up incline, the operator is merely required to pull, within a period of time from turning-on of the up switch 17 to turning-off thereof, the transporter with the drag rod 3 at a speed that the center of gravity of the object 13 comes always above the axle 6.

On the other hand, referring to Fig. 9, when the operator passes from the flat of the ground surface to a down incline thereof, the operation arm 2 is pivoted downward on the supporting shaft 18 as a fulcrum so that an down switch 18 is turned on by the operation arm 2 on the lower face thereof, thus starting operation of the drive shaft 9 to rotate the drive arm 1 on the side of a rear wheel 8. Referring to Fig.

10, the operator continues to go on the down incline, and when the front wheel 7 of the transporter reaches the down incline, the down face oi the operation arm 2 is disengaged from the down switch 18 to turn off same. Accordingly, in case that the transporter is on the down incline. the operator is merely required to pull, within this period of time, the transporter with the drag rod 3 at a speed that the center of gravity of the object 13 comes always above the axle 6.

If a stop position of the drive shaft 9, i.e., a position of the center of gravity of the object 13. is not optimal when the up switch 17 or the down switch 18 is turned off, the position of the drive arm 1 can be adjusted fine, if necessary. by switching operation mode to manual mode.

When putting down the object 13 on the ground after its transport to the predetermined place, the drive arm 1 is rotated on the side of the rear wheel 8 in manual mode.

Having described an embodlment with reference to the drawings, it is to be noted that the present invention is not limited thereto, but various modifications may be made thereln without departing from the scope of the claims. By way of example, the following modifications or the comblnatlon thereof are possible.

First, the drive mechanism for operating the drive arm 9 may be of the combination of an electric motor and a mechanical device, and include a pneumatic cylinder.

Secondly, when the drive mechanism uses electric power, a power source may be of a charging type battery or a small-sized generator, or of a power supply for domestic use by providing a power cord.

Thirdly, different lifting members such as lever type vacuum suction cup, etc., can be used in place of the hook 12.

Fourthly, a sensor control system can be added to correctly recognize the amplitude of variation of the inclination angle of the ground surface 15 during transport, and accurately indicate and control the amplitude of movement of the drive arm 1 relative to the above amplitude of variation.

Fifthly, referring to Fig. 5, if the transporter is designed and constructed to have a form enabllng a larger angle formed by the operation arm 2 and the ground surface 15, the center of gravity of the object 13 can be held always above the axle 6 in keeping always the rear wheel 8 apart from the ground surface 15 during transport.

Sixthly, in case that the ground surface 15 or a contact surface is flat as far as a predetermined point to which the object 13 has to be transported, and that the center of gravity of the obJect 13 is relatively stable, a rack may be mounted on the auxiliary arm 4 to carry the object 13. the lower face thereof being in contact with the rack during transport.

Seventhly, a reinforcing member can be added between the drive arm 1 and the auxiliary arm 4 for preventing torsion of the transporter, or a brake mechanism can be added for increasing the safety of work during movement of the transporter.

Eightnly, an extension mechanism can be added to the drive arm 1, the auxiliary arm 4, or the drag bar 3, or all thereof, for further increase in the operativity of the transporter.

Ninthly, referring to Flg. 11, in case that the drive arm 1 is provided with an extension mechanism, if the two auxiliary arms 4 are integrally formed to be an U-shape, and the front wheel 7 is mounted within the auxiliary arm 4, and the axle 8 and the reinforcing plates 20, 21 are eliminated, the object 13 can be lifted up and down only by extension motion of the drive arm 1, resulting in more facile transport of heavy or long objects.

Tenthly, referring to Fig. 12, the mounting position of the drive shaft 9 and the cylinder 10 can be changed to drive the drive arm .1 on the side of the drag arm 3.

Eleventhly, referring to Fig. 13. if the length of the auxiliary arm 4 is decreased in addition to the modification No. 10, transport work can be done without an end of the drive arm 4 being knocked against a wall when lifting up the object 13 located near the wall, or lifting down same near the wall.

Upon lifting up or lifting-down of the object 13, for minimizing a load applying to the oporator by movement of the center of gravity of the object 13 with rotation of the drive arm 1, a support 22 as usually received or housed within the auxiliary arm 4 is drawn out temporarily therefrom so that one end thereof touches to the ground. If the drag bar 3 with extension mechanism is adopted, and the operator holds same in its extension state upon lifting-up or lifting-down of the object 13, the above load can be further decreased.

Lastly, the transporter may be provided with traction means such as an engine, etc. for automatic operation.

Claims

Claims:

1. A transporter for carrying an object, comprising: first arm means for lifting the object; second arm means for supporting the first arm means; wheel means, rotatably mounted on the second arm means, for enabling movement of the transporter across a surface, the wheel means having an axis; sensor means for sensing a variation of an inclination angle- of the surface; and drive means for driving the first arm means, in response to the variation of the inclination angle, so as to tend to maintain the center of gravity of the object above the axis of the wheel means.

2. A transporter as claimed in claim 1, wherein the first arm means has one end disposed above the axis of the wheel means.

3. A transporter as claimed in claim 1 or 2, wherein the first arm means comprises a pair of drive arms.

4. A transporter as claimed in any of claims 1 to 3, wherein the first arm means includes an extension mechanism.

5. A transporter as claimed in any of claims 1 to 4, wherein the drive means comprises a hydraulic pump with a motor, a hydraulic cylinder, a drive shaft slidably fitted therein, and a level switch.

6. A transporter as claimed in any of claims 1 to 4, wherein the drive means include a pneumatic cylinder.

7. A transporter as claimed in claim 5 or 6, wherein the drive means has one end connected to the first arm means and another end connected to the second arm means at the rear portion thereof with respect to the forward direction of the transporter.

8. A transporter as claimed in claim 5 or 6, wherein said drive means has one end connected to the first arm means and another end connected to the second arm means at the front portion thereof with respect to the forward direction of the transporter.

9. A transporter as claimed in any preceding claim, wherein the second arm means comprises a pair of auxiliary arms.

10. A transporter as claimed in claim 9, wherein the auxiliary arms a part of a U-shaped structure.

11. A transporter as claimed in claim 9 or 10, wherein the second arm means includes a pair of supports.

12. A transporter as claimed in any preceding claim, wherein said sensor means includes an up switch and a down switch.

13. A transporter as claimed in any preceding claim, wherein the sensor means includes a sensor control system.

14. A transporter substantially as described with reference to, and as shown in, Figures 1 to 10, Figure 11, Figure 12, or Figure 13 of the accompanying drawings.