GB2055320A - Apparatus for mechanically acting on a structural member - Google Patents

Abstract

A pressure increasing device C supplies hydraulic fluid to a hydraulic piston and cylinder unit D in a pressing device B having opposed holders 57 which locate a tubular member 7 and which accommodate at least one tool such as opposed punches 63. The hydraulic unit D acts via levers 43 to move the holders 57 together before the punches 63 act. In another embodiment, a single punch is moved directly by a hydraulic piston-and-cylinder unit towards a single holder locating the tubular member. <IMAGE>

Description

SPECIFICATION Apparatus for mechanically acting on a structural member The present invention relates to apparatus for mechanically acting on a structural member, e.g. for punching or locally flattening a tubular component for the frame of a baby carriage. In a conventional type of a baby carriage, a number of tubular members are used.

As one of the methods for making some holes or crushed portions in a specified place in a carriage frame or a hand rail, formed by the members, the carriage frame or the hand rail is placed between a die and a plate holder to perform a punching operation under an upward or downward movement of the punch.

The present invention provides apparatus for mechanically acting on a structural member, comprising a pressure increasing device, a pressing device including a hydraulic pistonand-cylinder unit, and means or transferring hydraulic fluid from the pressure increasing device to the said unit, the pressing device comprising a holding element for locating the structural member, an operating element for mechanically acting on the structural member when located by the structural member, and means for moving the elements towards each other, the said moving means including the said unit.

A preferred apparatus for cutting holes in a structural member comprises a pressure increasing device, a machining device including a hydraulic cylinder and a pressing mechanism, and means for transferring hydraulic fluid from the pressure increasing device to the hydraulic cylinder, said pressing mechanism including opposing holding elements having a surface for conformal engagement with said structural member, means for moving said holding elements in opposite directions, relative to each other and cutting means operatively disposed in at least one of said holding elements for cutting said structural member while held in said conformal engagement with said holding elements.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a partially broken away front elevational view showing a pressure increasing machine and a working or machinery device connected with each other via a pressure feeding passage; Figure 2 is a partially broken away front elevational view showing a condition in which holes are punched in a work-piece; Figure 3 is a perspective view of the machining device; Figure 4 is a partially broken away side elevational view of the machining device; Figure 5 is a partially broken away front elevational view of another type of machining device; Figure 6 is a partially broken away front elevational view showing a condition in which holes are punched in a work-piece; Figure 7 is a top plan view of the machining device;; Figure 8 is a side elevational view in which both types of machining devices are installed at the location of machining of the component rods, fixed to a mounting frame; Figure 9 is a sectional view taken along line X-X of Fig. 8; and Figure 10 is a top plan view of a pressure increasing machine fixed on a support base.

In the drawings, reference symbol C indicates a pressure increasing machine which comprises a pneumatic piston-and-cylinder unit 1', a hydraulic piston-and-cylinder unit 2', and a reservoir tank 4 communicating with the hydraulic unit 2'. The pneumatic cylinder 1 is composed of a hydraulic cylinder cover 8, a pneumatic cylinder cover 9, and a cylinder tube 10 arranged between both covers 8 and 9. The hydraulic cylinder cover 8 has the form of a substantially circular plate having a circular flange 11 projecting outwardly in its central portion and further having a circular flange 12 at its inner side and spaced apart from its circumference. In the cylinder cover 8 an attachment hold 13 for the hydraulic cylinder 2, partly defined by the flange 11, is in alignment with a sliding hole 14 for a piston rod 5.A feeding hole 15 providing communication between the reservoir tank 4 and the hydraulic cylinder 2 opens in the circumferential wall of the attachment hole 13.

The pneumatic cylinder cover 9 comprises a substantially circular plate whose inner surface has a second flange 12. The tube 10 is arranged between the two flanges 12. Tie rods 16 are arranged between the cover 9 and the cover 8 outside the tube 10 and are fastened by nuts 17 to form the pneumatic cylinder 1.

In the pneumatic cylinder 1 are arranged a piston 3 and the piston rod 5, which projects horizontally from a central part of the piston 3. The piston 3 comprises a circular plate having a packing 18 at its circumferential surface, and is arranged to contact the inner surface of the cylinder tube 10. The piston 3 is slidable in a forward or rearward direction under an increasing or decreasing pneumatic pressure in the cylinder tube 10. The piston rod 5 has at its rear end an axial part 19 having a smaller diameter. The axial part 19 is fitted in a small hole 20 in the central part of the piston 3, and a set nut 21 is threadably fitted to the axial part 19 projecting from the rear surface of the piston 3, thereby attaching the piston 3 to the rod 5.The piston rod 5 is passed through the sliding hole 14 of the cover 8 in response to the movement of the piston 3 and thereby is slidable into the hydraulic cylinder 2.

At the rear and lower end of the pneumatic cylinder cover 9 are fixed two pneumatic couplings 23, respectively connected to a pressure reduction side and a pressure increasing side. The coupling 23 communicate with a front pressure-reduction chamber d and a rear pressure-applying chamber dt, separated by the piston 3, via a pressure applying passage 24 and a pressure reduction passage 25.

The reservoir tank 4 is arranged between the pneumatic cylinder cover 9 and the hydraulic cylinder cover 8 above the cylinder tube 10 of the pneumatic unit 1'.

The hydraulic unit 2' is constituted by the cylinder 2 and the piston rod 5, and an adapter 26 is provided at a leading end of the cylinder 2. The cylinder 2 has a circular flange 27 projecting from its rear part. The flange 27 abuts against the flange 11 of the cylinder cover 8, both flanges being fixed together by screws 29. The rear end of the cylinder 1 is fitted in the attachment hole 13 of the cylinder cover 8.

The piston rod 5 is moved forwardly in the cylinder 2 by a forward movement of the piston 3 caused by compressed air forced into the pressure applying chambder d' of the pneumatic cylinder 1, whereby the hydraulic oil in the cylinder 2 is expelled through a hydraulic passage 6 connected to the adapter 26. In this case, it is assumed that the pneumatic pressure in the pressure applying chamber d' is p; the cross sectional area of the piston 3 is A; the hydraulic pressure in the hydraulic cylinder 2 is P; and the cross sectional area of the piston rod 5 is a From the equation, p X A = P x a, the hydraulic pressure P shows a high pressure output 11 to 25 times higher than the pneumatic pressure p.

The hydraulic line 6 is composed of a branch chamber 30 and a number of oil lines 31 adapted to be connected to the branch chamber 30. The other ends of the oil lines 31 are each connected to a respective machining device B. As to the machining device B, there are two kinds, that is, type I shown in Figs. 1 to 4 and type II shown in Figs. 5 to 7.

Referring first to type I, the machining device B is composed of a hydraulic pistonand-cylinder unit D and a pressing mechanism A. The hydraulic unit D includes an end cover 32, an end cover 33, a cylinder 34, and a piston rod 35.

The cover 32 has a stepped part 37 at one side of a circular plate 36, and a guide rod part 39 horizontally extending from the lower end of the foremost vertical surface 38 of the part 37. At a rear cirumferential surface of the cover 32 is set a hydraulic coupling 40 for use in connecting a hydraulic line 31, and further, the cover 32 is provided with a hydraulic passage hole 41 having one end communicating with the hydraulic coupling 40 and the other end opening in the said vertical plane 38. Reference numeral 42 indicates connecting pieces which project at the back of the cover 32 and pivot to a lever 43 cooperatively connected to the pressing mechanism A to be described later.

The piston rod 35 has a sliding head 44 at its rear end and a reduced diameter part 45'.

The inner circumferential surface of the piston rod 35 is in sliding contact with the outer circumferential surface of the guide rod 39 via packing 46, and the rear surface of the sliding head 44 normally abuts against the vertical surface 38 in such a way that the hydraulic flow port 41 is closed. At the front end of the piston rod 35 there are further connection pieces 42 which is pivoted to a second lever 43 cooperatively connected to the pressing mechanism A to be described later.

The cylinder 34 has a cylindrical shape having one end threadably engaged on the stepped part 37 of the cover 32, to which an O-ring 47 is fitted. The inner circumferential surface of the cylinder 34 engages the circumferential surface of the head 44 of the piston rod 35 with an 0being 47 being installed in the head.

The cover 33 functions somewhat like a cap nut, its rear end being threadably engaged with the front end of the cylinder 34. At the front end of the cover 33 is formed, in a steplike manner, a supporting wall 49 for restraining a compression spring 48 which encompasses the reduced-diameter part 45 of the piston rod 35. The spring 48 is arranged between the inner surface of the supporting wall 49 and the facing surface of the sliding head 44 of the piston rod 35.

Each lever 43 is pivoted at its centre to a pair of attachment pieces 51 on a base 50 for the pressing mechanism A and further its top end abuts against a projection piece 53 of the pressing mechanism A. The hydraulic oil fed into the hydraulic unit D by the pressure increasing machine C pushes the piston rod 35 against the force of the spring 48 and then flows into a hydraulic chamber 54 formed between the guide rod 39 and the cylinder 34. Thus, the cover 32 and the piston rod 35 are extended or separated from each other in a leftward and rightward direction to push the projection pieces 53 of the pressing mechanism A via the levers 43.

The pressing mechanism A includes support pieces 55 on the base 50, pressing jaws 56, and holder pieces 57 for holding a tubular component 7 of a baby carriage.

The pressing jaws 56 are of channel section and have projection pieces 53 extending from their rear surfaces. Cushion members 59 are fitted in the grooves of the jaws 56 and project from them. In front of the cushion members 59 are positioned the holder pieces 57, having semi-circular holder recesses 60 facing each other. The pressing jaws 56 and the holder pieces 57 are provided with aligned guide holes 61 accommodating guide shafts 62, so that the pressing jaws 56 and the holder pieces 57 may be moved towards and away from each other. The holder pieces 57 are provided with holes 64 which are used in feeding punches 63 into or out of the holder recesses 60 for the component 7. The punches 63 extend into the holes 64 and are fixed in the pressing jaws 56 by set screws 65.

On the base 50 at the rear ends of the pressing jaws 56 are fixed L-shaped support pieces 55 which are disposed in such a way that the projection pieces 53 are held therebetween. In vertical portions 66 of the support pieces 55 there are placed holes 67, and return-spring guide shafts 68 are inserted in the holes 67. The front ends of the shafts 68 are fixed to the pressing jaws 56 and washers 70 are arranged at the rear ends of the shafts 68, being retained by loose nuts 69. Return springs 71 (compression springs) are arranged between the vertical pieces 66 and the washers 70. Threaded rods 72 for use in setting the position of the holder pieces 57 are passed through the pressing jaws 56 and engage the holder pieces 57. Rotation of a threaded rod 72 causes the associated solder piece 57 to be moved relative to the associated jaw 56.

When the cover 32 and the piston rod 35 of the hydraulic unit D are extended apart and the levers 43 push the right and left projection pieces 53, the pressing jaws 56 are moved in opposite directions against the resilient force of the return springs 71. Thus, the holder pieces 57 in front of the pressing jaws 56 are forced together via the cushion members 59 and the component 7 becomes held by the opposing semi-circular holder recesses 60. The pressing jaws 56 depress the cushion members 59 and abut against the holder pieces 57. The punches 63 project from the holes 64 and punch opposed holes in the component 7. The cushion members 59 are so arranged that the punches 63 projected only after the component 7 is positively held by the holder piece 57.Thus, the punches 63 do not come into play until after the holder pieces 57 are brought into contact with the component 7 and accordingly the punches 63 are prevented from making undesirable places or irregular holes in undesirable places.

When the compressed air is forced into the pressure reduction chamber 8 of the pressure increasing machine C to cause the piston rod 5 in the cylinder 2 to move in the rearward direction, the hydraulic oil in the hydraulic chamber 54 of the hydraulic cylinder D is reversed in the hydraulic line 31 and then flows into the reservoir tank 4. Then, since the hydraulic chamber 54 possesses a negative pressure, the cover 32 and the piston 35 are returned to their original place and the levers 43 are rotated via the connection pieces 42 at both ends. Then the top ends of the levers 43 are moved away from the projection pieces 53. The pressing jaws 56 and the holder pieces 57 are thus moved in the rearward direction and returned to their original starting position. The component 7, having had holes punched in it, can then be removed.

In the above description, a preferred embodiment of the machining device B as a punching device is illustrated. Optionally, the punches 63 can be replaced with cutters to form a cutting device and thereby the leading ends of the punches 63 would be depressed resulting in the formation of a choking device.

Referring now to Figs. 5 to 7, the machining device B' of type II is described. The machining device B' is made such that a pressing mechanism A' and a hydraulic piston-and-cylinder unit D' are integrally assembled. The hydraulic unit D' has substantially the same structure as the above-described hydraulic unit D, and a rear surface of the cover 32 is fixed to a fixing member 73 and engaged therewith.

The fixing member 73 is made of a flat plate and two such fixing dies 73 are arranged in parallel at a specific spacing. At the four corners of each plate there are fitting holes 74 and threaded holes 75 which are continuous with the fitting holes 74. Slide shafts 77 for a slide piece 76 are arranged between both fixing plates 73 and further fixed to the threaded shafts 78 projecting from the threaded holes 75 via fastening nuts 79. At the lower ends of the fixing plates 73, L-shaped channel bases 80 are fixed against the outer surfaces of the fixing plates 73 by the nuts 79, when the nuts are fastened.

The pressing mechanism A' is composed of a movable member 76 sliding on the guide shaft 77, support pieces 81 for the component 7, a return mechanism 82 and a punch device 83. The movable member 76 is a channel section formed with guide holes 84 for the guide shafts 77. The rear surface of the movable member 76 abuts against the piston rod 35, projecting from the cover 33 of the hydraulic unit D'. The return mechanism 82 is composed of a rod 85 and a spring 86.

The rod 85 passes through the guide rod 39 in the cover 32 and through the piston rod 35, and is threadably engaged with the movable member 76; the other end of the guide rod 85 projects outwardly from a hole 87 in the fixing member 73. The spring 86 is a compression spring which is arranged between one spring support piece 88 having a part fitted in the hole 87 and another spring support piece 88, which is fixed to the end of the rod 85 by a nut 89. The support pieces 81 for the component 7 are constituted by support elements 90 pivoted to respective side surfaces of the fixing member 73 and an abutment element 91 pivoted to the fixing member 73. Each support element 90 is made of a flat-plate and has a support hole 92 having a larger diameter than that of the component 7 at its central location.The abutment element 91 is fitted in a groove 94 made in one surface of the fixing member 73, i.e. the inner surface facing the moving member 76, and is pivoted to the fixing die 73 via pins 93. The abutment element 91 is provided with a semi-circular recess 95 and at the central part of the recess 95 is formed a punch projection hold 96' which is continuous with a hole in the fixing member 73.

Thus, a supporting hole 92 for the support element 90 is provided and the semi-circular recess 95 of the abutment element 91 abuts one end of the component 7 projecting from other support hole 92. The one semi-circular portion of the component 7 is supported by the support hole 92 and the other semicircular portion of the component is supported by the recess 95, thereby providing a firm support for the component.

The punch device 83 is composed of a punch 96 and a punch support member 97, the punch support member 97 being fixed in the channel 98 of the moving member 76.

The punch 96 is inserted through the punch support member 97 and fixed to a leading end of the moving shaft 85.

Thus, the hydraulic oil fed via the pressure increasing machine C pushes the piston rod 35 against the force of the spring 48 and flows into the hydraulic chamber 54 formed between the guide rod 39 and the cylinder 34. Then, the piston rod 35 moves in the forward direction against the force of the spring 86 and moves the movable member 76 in a forward direction, thereby making aligned punch holes in the component 7 by the punch 96.

When the hydraulic pressure is decreased, the hydraulic pressure chamber 54 exhibits a negative pressure and the movable member 76 moves in a rearward direction under the return force of the spring 86. The-piston rod 35 is also moved rearwardly with the movement of the movable member 76, returning the device to its original starting condition.

Then, the component 7 which has been punched with holes is pulled apart from the pipe support elements 90 and removed.

The above description has been made with respect to the machining device B' as a punching machine, but it is an option that the punch 96 can be replaced with a cutter to form a cutting device and a leading end of the punch 96 is pressed to show a choke device.

Referring now to Figs. 8 and 9, an installed state of the apparatus is described. It is assumed that a tubular component 7 of a baby carriage, e.g. a frame pipe 7', is to be machined. Both ends are fitted over a small shaft 101 at the leading end of a fitting shaft 100 projected from a fixed member 99 fixed on a mounting frame base E. Machining devices B,B' are fixed on the mount 50 or L-shaped channel 80 on the mounting frame base E which corresponds to the desired machining point, by bolts 103.

On the support base F over the mounting frame base E are mounted the pressure increasing machine C, a regulator 104, a solenoid valve 105, and an air filter 106, and the mounting frame base E is provided with a control box G. The mounting frame base E and the support base F are integrally connected, the lower ends of the mounting frame base E being provided with casters 107 allowing the mounting frame base to be moved to a desired location.

When the solenoid valve 106 is operated under the control of the control box G to cause the compressed air to be fed into the pressure increasing machine C, a desired machining operation is performed at each of the points along the component 7.

In the above description, both machining devices B,B' are used for machining the component 7. It is alternatively possible to install a plurality of separate machining devices B on the mounting frame base E or to install a plurality of separate machining devices B' on the mounting base E.

As described above, the machining devices are each provided with hydraulic cylinders connected to the pressure increasing machines, respectively, and simultaneous press machining enables simultaneous punching at desired points of the component, resulting in an extremely improved workability compared with that of a conventional system.

Since each of the hydraulic cylinders is connected to a pressure increasing machine, each of the cylinders can provide a sufficient output, even if it is small in size. Therefore, it is possible to make a small-sized machining device having each of the cylinders assembled therein and further to make an overall smallsized system. Each of the machining devices may be relocated in a place where the pipe member is to be crushed or punched.

In the second embodiment, both a fixing member and a movable member are oppositely arranged on a mounting base, the piston rod of the hydraulic cylinder being engaged with the back portion of the movable member. A rod, with one end arranged in the movable member, is axially installed in the hydraulic cylinder. A spring which is provided for biasing the said piston rod to cause the same to be returned is engaged with said rod, so that if a coupling for a hydraulic passage to be fed in the hydraulic cylinder is arranged only at the feeding side, a positive operation is confirmed to perform a machining operation on the component. Then the members can be returned to their original status by the resilient force of the spring after the machining opera tion.

Thus, as found in a conventional hydraulic cylinder, it is not necessary to mount various tools such as couplings at the feeding side and the suction side, whereby the structure may be simplified and the fixing member, movable member, hydraulic cylinder, and spring are connected to make a compact system.

In the first embodiment, a pair of movable pressing jaws are installed on a mount. Levers with one end thereof engaged with an outer end of each pressing jaw are pivotally arranged thereon and both the case side and the piston rod side of the hydraulic unit are connected for each of the ends of the levers, so that the movement of the levers caused by an extension of one hydraulic unit causes the pressing jaws to be moved so that a pipe member may be machined from both sides thereof. Thus, it is not necessary to connect a separate hydraulic cylinder to each of a pair of pressing jaws, thereby making it possible to make a simple structure and also to provide a compact system.

One end of the lever, the mid portion of which is pivoted to the mounting base for the pressing jaw, is connected to both ends of the hydraulic unit and the end of the lever piece abuts against the outer end of a pair of oppositely faced pressing jaws, so that it is possible to increase the output transmitted by the hydraulic line, in using a lever principle by extending the length between a pivotal point of the mounting base for the lever and the connecting part at both ends of the hydraulic unit or by reducing the length between a pivotal point for the mounting base and the engagement with the outer end of the pressing jaw.

Claims (7)

1. Apparatus for mechanically acting on a structural member, comprising a pressure increasing device, a pressing device including a hydraulic piston-and-cylinder unit, and means for transferring hydraulic fluid from the pressure increasing device to the said unit, the pressing device comprising a holding element for locating the structural member, an operating element for mechanically acting on the structural member when located by the structural member, and means for moving the elements towards each other, the said moving means including the said unit.

2. Apparatus as claimed in claim 1, in which there are two opposed holding elements and two opposed operating elements, the operating elements being movably mounted in the holding elements.

3. Apparatus as claimed in claim 1 or 2, in which the said means includes lever arms pivotally connected to opposite ends of the said unit.

4. Apparatus as claimed in claim 3, including springs acting on the lever arms in opposition to the said unit.

5. Apparatus as claimed in any of claims 1 to 4, including a plurality of said pressing devices and means for transferring hydraulic fluid from the pressure increasing device to the said pressing devices simultaneously.

6. Apparatus as claimed in any of claims 1 to 5, in which the operating element or at least one of the operating elements is a cutting punch.

7. Apparatus for mechanically acting on a structural member, substantially as described with reference to any of the embodiments illustrated in the accompanying drawings.