GB2087742A

GB2087742A - Pneumatically operated toy crane

Info

Publication number: GB2087742A
Application number: GB8134686A
Authority: GB
Original assignee: Tomy Kogyo Co Ltd
Current assignee: Tomy Kogyo Co Ltd
Priority date: 1980-11-19
Filing date: 1981-11-18
Publication date: 1982-06-03
Also published as: JPS6121119Y2; GB2087742B; ES261952U; ES261952Y; JPS5787799U

Abstract

The boom (31) of a crane (2) is raised and lowered by an air supply (1) which exhausts and intakes air alternately and which is connected to a bellows (41) by way of a valve mechanism (34). The valve mechanism including positive and negative pressure operated valves (38', 38) by means of which pressure generated during exhaust of the air supply expands the bellows raising the boom, which pressure is maintained in the bellows during the intake of the air supply through the negative pressure operated valve (38). A purge valve (44) is provided to exhaust air from the bellows to atmosphere so contracting the bellows and causing the crane boom to descend. <IMAGE>

Description

SPECIFICATION Pneumatically operated toy crane The present invention relates to a toy crane which moves up and down being powered by the compressed air.

The object of the invention is to realize a toy which performs interesting movement, i.e., which gradually lifts up the crane, by using a simply constructed air supply which exhausts and intakes the air alternatingly, so that the crane is pushed up by the exhausted air only.

For this purpose according to this invention, the toy crane comprises an air supply which exhausts and intakes the airalternatingly, a crane body which hoists a crane arm that is rotatably supported with its base end as a centre relying upon the expanding and contracting operation of a bellows, and a valve device including an air path which connects said air supply to the bellows of said crane body, wherein the valve device consists of a positive pressureoperated valve, a negative pressure-operated valve, and a purge valve for exhausting the air filled in the bellows such that the crane which has been hoisted by the expanded bellows is allowed to descend.

An embodiment of the present invention will now be explained further hereinbelow by way of example, only with reference to the accompanying drawings, in which: Fig. lisa perspective view showing the whole toy; Fig. 2 is a perspective view of the crane unit; Fig. 3 is a perspective view of the compressor unit when a cell box is opened; Fig. 4 is a simplified cross-sectional view of the compressor unit showing the working parts; Fig. 5 is a bottom view of the crane unit; Fig. 6 is a perspective view of the frame of the crane; Fig. 7 is a perspective view of the valve mechanism; Fig. 8 is a cross-sectional view of the valve mechanism; and Fig. 9 is a perspective view of a tongue piece which constitutes a valve, and a cylinder for receiving the tongue piece.

The pneumatically operated toy crane according to this invention consists of a compressor unit 1 for supplying the air and a crane unit 2 which are connected together through a flexible tube 3 which sends the air.

The compressor unit 1 has a shape similar two a practical compressor that is used in the construction site, has a hollow body 4 and wheels 5 attached to the lower portions of the body 4. The upper portion of the rear half of the body 4 serves as a cell box 6 having a cover 6a which can be freely opened and closed, and accommodates cells 7 as illustrated in Fig. 3.

A cylinder unit 8 is provided in the front portion of the body 4 in parallel with the cell box 6. Referring to Fig. 4, the cylinder unit 8 consists of a transparent cylindrical cover9 having a shape resembling cooling fins, and a cylinder 10 secured in the cover 9. The upper end of the cylinder 10 serves as an air supply port 10a of a small diameter which protrudes beyond the upper end of the cover 9, and an end of the above-mentioned tube 3 is connected to the supply port 10a.

A piston 11 is fitted in the cylinder 10, and the lower end of a rod 11 a is coupled to a drive mechanism which is installed in the body 4. Namely, a motor 12 is disposed in the body 4 beneath the cell box 6. A pinion gear 13 fastened to the tip of the output shaft of the motor is in mesh with a gear 15 which is rotatably and loosely supported by a drive shaft 14 that is laterally supported in parallel with the output shaft.

A pinion gear 16 which is formed together with the gear 15 as a unitary structure is in mesh with a gear 18 which is supported by another rotary shaft 17 that is laterally supported in parallel with the drive shaft 14. Furthermore, a pinion gear 19 which is formed together with the gear 18 as a unitary structure is engaged with a gear 20 that is fastened to the drive shaft 14.

The above-mentioned gear train inclusive of the pinion gear 13 constitutes a reduction mechanism which transmits the rotation of the motor 12 to the drive shaft 14 at a predetermined reduction ratio. A cam plate 21 which also serves as a fly-wheel is fastened to an end of the drive shaft 14 beneath the piston 11, and the lower end of the piston rod 1 lea is coupled to a coupling member 22 which is protruded from a deflected position on the outer side of the cam plate 21.The upper end of the piston rod 11a is swingably coupled by a pin to the piston 11.

A lever 23 for operating the engine is attached to the side surface at the front portion of the body 4.

The lever 23 for operating the engine has a knob 23a at an upper end thereof. The lower end of the lever 23 is rotatably supported in a cylindrical swollen portion 4a which is protruded at the front end of the body 4, and has. on its side surface, a moving contact 24 as shown in Fig. 4. The moving contact 24 is formed nearly in the shape of a fan, and a portion thereof is connected to one electrode of a cell which is the power supply through a lead wire 25.

A fixed contact 26 is mounted on the side of the swollen portion 4a to oppose to the moving contact 24, and is connected to another electrode of the cell through a lead wire 27. Therefore, when the lever 23 for operating the engine is turned so that the moving contact 24 is brought into contact with the fixed con tact 26, a power-supply circuit forthe motor 12 is closed. Accordingly, the rotation which is reduced at a predetermined reduction ratio through the above-mentioned gear train is transmitted to the cam plate 21, the piston 11 is caused to move up and down via the rod 1 la accompanying the rotation of the cam plate 21, the air in the cylinder 10 is expelled and is intaken, and the positive pressure and negative pressure are supplied to the crane unit 2 via the tube 3.

Next, the crane unit is constructed as shown in Figs. 1, 2 and 5. Namely, the crane unit 2 has a frame 28 which is provided with wheels 29. Further, a pair of brackets 30,30 are protruded from the tip of the frame 28, and a first crane arm 31 is rotatably supported atthe end of the brackets. The crane arm 31 consists of an elongated and hollow frame and accommodates therein a second crane arm 32 maintaining a relatively strong frictional relation.

Therefore, the second crane arm 32 can be pulled out of the first crane arm 31 when it is pulled by hand. A gondola 33 for carrying dolls is swingably attached to the tip of the second crane arm 32.

The frame 28 of the crane unit 2 is formed hollow, and accommodates a valve mechanism 34 as shown in Figs. 7 and 8. The valve mechanism 34 consists of a sealed and elongated frame and has on a portion thereof a nipple 35 to which the tube 3 will be connected. The nipple 35 is communicated with a first valve chamber 36 which is constructed in the form of a sealed frame. In the first valve chamber 36 is secured a cylinder 37 having a partly cut-away portion 37a that is communicated with the first valve chamber 36.

A positive pressure operated valve 38 is disposed between the upper end of the cylinder 37 and the top plate of the first valve chamber 36. The valve 38 has on the inner side a tongue piece 38b which is formed by a horseshoe-shaped cut-away portion 38a as shown in Fig. 9, and is made of an elastic material such as rubberorthe like. The tongue piece 38 closes, from the lower side, a through hole 36a that is formed in the first valve chamber 36.

The first valve chamber 36 is communicated with a second valve chamber 39 which is formed beneath the first valve chamber, via a through hole 39a. A cylinder 37' of the same shape as that of the first valve chamber 36 is provided in the second valve chamber 39 in a manner to surround the through hole 39a. The cylinder 37' has an opening 37'a. A negative pressure operated valve 38' of the shape same as that of the above-mentioned valve 38 is disposed between the cylinder 37' and the first valve chamber 36, and a tongue piece 38'b closes the through hole 39a from the lower side.

A nipple 40 is protruded on the upper surface at one end of the second valve chamber 39, and the lower end of a bellows 41 is coupled to the nipple 40.

A cylindrical cover 42 of which the lower side is open is so placed asto coverthe outer side of the bellows 41, and is ascended or descended accompanying the expansion or contraction of the bellows 41,the cover having a roller 43 on the upper portion thereof. The cover 42 is so positioned as to ascend and descend through an opening 52 (Fig. 6) that is formed in the upper surface of the frame 28 near the root portion of the arm 31. When the cover 42 is raised, the roller 43 comes into contact with the lower surface of the crane arm 31, such that the end of the crane arm 30 is lifted up.

Further, an exhaust button 44 is provided at the other end of the second valve chamber 39 as shown in Fig 8. The exhaust button 44 is attached to the upper end of a shaft 45 which vertically penetrates through the second valve chamber 39 to move in the upper and lower directions, and is protruded beyond the upper surface of the frame 28 on the outer side of the valve mechanism 34. A sealing plate 47 made of rubber or the like is fitted to the inner side of a cylindrical portion 46 which supports the shaft 45 of the exhaust button 44 maintaining the freedom of movement in the upper and lower directions, and the shaft 45 is allowed to run penetrating through the sealing plate 47.The sealing plate 47 has through holes 47a, and the valve chamber 39 is communicated with the external air via the through holes 47a and a through hole 46a to which the shaft 45 in the cylindrical portion 46 is fitted.

An opening/closing plate 48 secured to the shaft 45 is located on the lower side of the sealing plate 47, and is pressed onto the sealing plate 47 being urged by a spring 49 which is located between the opening closing plate 48 and the bottom surface of the second valve chamber 39, thereby to close the through hole 47a.

Therefore, when the exhaust button 44 is downwardly depressed against the spring 49, an opening/closing plate 48 is lowered, and the second valve chamber 39 is communicated with the open air via the through hole 47a.

A safety valve 50 is provided in the vicinity of the exhaust button 44. The safety valve 50 is formed in a cylindrical shape and is communicated with the open air via a through hole 39a formed in the second valve chamber 39, and further possesses a valve 51 which closes the through hole 39a being compressed by a predetermined force of the spring 52.

Next, the operation of the thus constructed embodiment will be illustrated below.

First, the operation lever 23 of the compressor unit 1 is turned in the direction ON so that the movable contact 24 comes into contact with the fixed contact 26. The electric circuit is then closed, and the motor 12 starts to run. Therefore, the cam plate 21 is rotated by the pinion gear 13 via the reduction gear mechanism, and the piston 11 moves up and down via the rod 11 a.

As the piston 11 moves up and down, the air in the cylinder 10 is supplied into the crane unit and is intaken alternatingly via the tube 3. This is explained below in further detail. When the piston 11 of the compressor unit is raised, the air in the cylinder 10 is supplied to the first valve chamber 36 of the valve mechanism on the side of the crane unit via the tube 3. The compressed air in the first valve chamber 36 opens the tongue piece 38'b of valve 38' which is closing the port between the first valve chamber 36 and the second valve chamber 39, and enters into the second valve chamber 39 through the cut-away portion 37a of the cylinder 37, and is further introduced into the bellows 41 via nipple 40 thereby to expand the bellows. As the bellows 41 expand, the cover 42 is lifted up and the first crane arm 31 is rotated counterclockwise in Figs. 1 and 2 via the roller43; i.e,. the tip of the crane arm 31 is lifted up. In this case, the rise in pressure in the first valve chamber 36 causes the tongue piece 38b of the valve 38 to close the through hole 36a.

Next, the air in the tube 3 is intaken when the piston 11 in the compressor unit is lowered, and a negative pressure is established in the first valve chamber 36. Therefore, the valve 38 in the valve chamber 36 is opened, and the open air is introduced through the hole 36a. At the same time, the valve 38' on the side of the second valve chamber 39 is closed; the compressed air does not escape from the valve chamber 39, and the bellows 41 does not contract. Therefore, among the positive pressure and negative pressure applied to the crane unit via tube 3, the positive pressure only can be selected by the abovementioned valve mechanism and can be applied to the bellows 41.

As the above-mentioned operation continues repetitively, the bellows 41 is gradually expanded, and the cover 42 is raised such that the tip of the crane arm 31 is lifted up.

To lower the tip of the crane arm 31,the exhaust button 44 is depressed. Therefore, the opening/closing plate 48 is lowered, the second valve chamber 39 is communicated with the open air via the through hole 47a of the sealing plate 47, and the compressed air in the valve chamber 39 is emitted into the open air. Since the valve chamber 39 is communicated with the interior of the bellows 41, the pressure in the bellows decreases. Namely, the bellows is pushed down by the weight of the crane arm; the crane arm is permitted to descend to an almost horizontal state.

If the operation of the compressor 1 is permitted to continue without depressing the exhaust button 44, the pressure in the second valve chamber 39 becomes so great as will destroy the bellows 41. To avoid this inconvenience, the tongue piece 51 of the safety valve 50 is opened by the compressed air introduced via the through hole 39a against the spring 59 when the pressure in the second valve chamber 39 increases above a predetermined level.

Accordingly, the air is emitted into the open air, and the bellows 41 is prevented from being destroyed.

According to this invention as will be obvious from the foregoing description, the valve device installed in the crane unit selects the exhaust air only from the intake air and the exhaust air supplied from the air supply thereby to expand the bellows, the crane arm is gradually lifted up by the expansion of the bellows, and when the purge valve is operated, the compressed air in the bellows is released into the open air such that the crane arm is allowed to descend by its own weight. In short, the invention provides a novel and interesting toy which is capable of hoisting the crane arm by utilizing the pneumatic pressure.

Claims

1. A pneumatically operated toy crane comprising a crane body having a crane arm that is rotatably supported about its base end and is raised and lowered respectively by the expansion and contraction of a bellows, a valve device for connecting to the bellows by way of an air path, an air supply which exhausts and intakes air alternatingly, the valve device comprising a positive pressure operated valve, a negative pressure operated valve, and a purge valve for exhausting the air fitted bellows such that the hoisted crane arm is allowed to descend.

2. Atoy crane as claimed in claim 1 in which the positive pressure-operated valve is opened by the pressure that is produced when the air is exhausted from said air supply to said air path thereby to feed the air into said bellows and in which the negative pressure operated valve is disposed between the positive pressure operated valve and said air supply and is opened by the pressure that is produced when the air is intaken into said air supply, thereby to communicate said air path with the open air.

3. Atoy crane as claimed in claim 1 or 2 in which the positive and negative pressure operated valves are flap valves.

4. Atoy crane as claimed in claim 1,2 or3 in which the purge valve is plunger operated and connects the bellows to atmosphere for exhausting the air in the bellows.

5. Atoy crane as claimed in any preceding claim in which safety valve is provided to prevent over pressurisation of the bellows.

6. A pneumatically operated toy crane constructed and arranged and adapted to operate substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.