The object of the invention is a device for pressing tight hose couplings, in particular, to pressure hoses or the like, the device being principally of the type which has been explained more closely in the introduct¬ ion of patent claim 1. In addition the device in accordance with the invention can also be used in a convenient manner for other work objects requiring radial pressing machining, such as the formation of a cone shape at the end of a pipe by pressing, in which the construct¬ ion of the machining j ws is suitable for the purpose.

From the earlier patent application 772659 of the applicant the said suitable device for the purpose has become known, by means of which the level of the tech¬ nique in the field has been raised markedly. In this device the part to be pressed is pressed in a radial direction by means of several tool parts at the same time in order to compress the said part and to achieve the fastening to the end of the hose.

In the tools there are two ring-shaped parts, arranged concentr cal y to move opposite to each other axially, on the inner surfaces of which have been formed guiding cones opening opposite to each other. Between these rings are fitted radial aws resting on the said cone surfaces, these being stressed tangentially relative to each other by means of springs so that the jaws move in a radial direction when a power device, for example a pressure cylinder, presses the ring-shaped parts axially. The said tools are placed principally at equal radii on a sequentially rotatable disc or the like so that each tool can be brought into operation in turn.

The disadvantage of this kind of construction is, how¬ ever, that the length of stroke of the machining jaws and the corresponding pressing depth are very small. This makes it more difficult to press such objects as have radially projecting parts, for example flanges, which require that the press parts have a large openin and pressing movement. It is of course possible to achieve the opening of the machining jaws by means of the device in accordance with the application 772659 by lengthening the cone-shaped surfaces of the ring- shaped parts so the length of movement of the machinin jaws is increased in the radial direction. In this cas however the size, of the device and- the length of the working movement of the power device become uneconomic ally large. Moreover, the machining speed becomes mat¬ erially slower since the part of the actual press move ment in the 'constant speed radial movement of the aws is small .

The purpose of this invention is to introduce a device for pressing tight ^' hose couplings, in particular, whic removes the above mentioned disadvantages and generall raises the level of technique in the field. These aims are achieved by the device in accordance with the inve tion in such a manner that the opening and closing of the jaws has been arranged to take place in two phases so that the beginning of the machining jaws opening phases and correspondingly the actual press stage, guided by the first c _x e- or wedge surface formed on the outer edge of the inner surface of both ring-shape elements, takes place more slowly than the final phase of the machine aws opening movement realised by means of the inner edge of the surface of both ring-shaped parts, or correspondingly the initial phase of the pre movement. Naturally the radial j ws have correspondingl tapered surfaces. Thus in the actual machining conside able saving can be achieved since the transition of th

machining jaws to the actual pressing position can be accomplished as a so-called quick movement. As a benefit of the large radial opening of the machining jaws is, for example, that a radially projecting part to be fastened to a hose, such as flange the diameter of which is considerably greater than that of the actual fastening part , can be pushed between the jaws in such a manner that the actual fastening part comes to the machining jaws in place and the pressing tight can be carried out by means of the two-phase press movement of the machining jaws.

Other benefits of the device in accordance with the invention are that the work movement of the power device, such as a pressure cylinder, is small compared with the opening magnitude of the machining jaws. The axial movement of the ring-shaped parts is also small that the space needed by the whole device is also very small compared with the embodiment ^• performing the same functions in accordance with the known level of tech- nique. Saving with regard to materials ^' is thus also achi eved .

For guiding the radial movement of the machining jaws of the pressing device operating in accordance with the principle introduced above, it has been necessary to develop in connection with the press jaws guiding mechanisms by means of which the machining surfaces of the said jaws are kept in their convenient position with regard to machining, that i s in a perpendicular position against the moving direction of the jaws during the whole radial movement . Since the coefficients of friction between the cone surfaces of the machining jaws and the- cone surfaces of the ring-shaped parts opera ing in conjunction with them are not in practice

equally large, the machining jaws easily tend to bend to a slanting position during the radial motion if no such guiding parts exist. The guiding parts are especially necessary when the radial aws move from the so-called swift movement cone surfaces of the rin shaped parts to the actual press surfaces so that between the ring-shaped parts and the machining jaws there is only line contact. In addition to their radi movement the machining jaws also move axially guided by the cone surfaces of the ring-shaped parts. Thus the guiding parts of the machining jaws need to be such that by means of them the jaws remain in their most advantageous position also during this axial mov ment .

The device in accordance with the invention is charac terised in what has been introduced in the characteri tics section of the enclosed patent claim.

One advantageous embodiment of the invention has been

^" illustrated more closely in the following explanation referring at the same time to the enclosed drawings i n wh i ch

Figure 1 shows the device in accordance with the in¬ vention, attached to the machine body,

Figure 2 shows the device viewed from the front,

Figure 3 shows the cross-section A-A of Figure 2, in which the machining jaws are in the clos posi t i on , and

Figure shows the machining jaws in their opened ^• posi t i on .

The device according to the invention has been fitted according to Figure 1 to the upper part of the machine body 2, in a horizontal position, and has been attach¬ ed to it by a bolt fastening 3- The machine body 2 has been made of stout flat bar iron and its side walls have been covered with sheet . Inside the machine body 2, under the device 1 has been placed the hydraulic driving machinery of the device, which is of known con¬ struction comprising a hydraulic pump with its motors, oil tanks and associated equipment (not shown in the figure). The upper part of device 1 has been covered with a casing part 4 which is removable from the top of the machine if necessary. To the rear part of the jacket 4 has been arranged a hydraulic cylinder per- forming a horizontal working movement which moves an¬ other ring-shaped part in the axial direction of the device. On the right in Figure 1 is shown the control panel of the device, by means of which the operations of the device are carried out el ect ro-hydraul i cal ly .

Figures 2-4 introduce more closely the pressing device

1 attached to the machine body 2. The device has been attached to the machine body by means of four nuts 5 which have been screwed to the ends of the four fast¬ ening and guiding rods 6 running axially in relation to the device. The pressing devices shown in the figures have two opposite, concentric, ring-shaped pressing circumferences 7 and 8. Of these the ring- shaped part 7 is fixed relative .o the machine body, being tightened against the shoulder in the end of the rod 6 by means of the nuts 5- The other ring-shaped part 8 has been arranged to move supported by the guiding rods 6. Both parts 7 and 8 have two cone sur¬ faces 9, 10 and 11, 12 opening inwards. Thus the outer surfaces of the ring-shaped parts 7 and 8, the taper

angle of which is smaller than that of the inner con surfaces 11 and 12, form the so-called press cone su faces, and correspondingly the cone surfaces 11 and form the so-called quick movement cone surfaces. At junction of the said surfaces there is a suitable ro ing in order to achieve a resilient transition. Betw the said ring-shaped parts 7 and 8 has been placed a ring-shaped radial jaw group, composed of radially p sector-shaped jaws 13, with on the back of the jaws syn-met rically placed in relation to their centre axi the inner press cone surfaces 14 and 15, correspondi to the cone surfaces 9 and 10, and correspondingly t outer quick movement cone surfaces 16 and 17 which c spond to the cone surfaces 11 and 12 of the ring-sha parts. At the junction of the jaws cone surfaces the is also a rounding in order to achieve a resilient transition. The jaws 13, of which there are 8 in thi embodiment, are held tangentially against each other by means of the springs 18. Thus the spring forces p the jaw group against each ring-shaped part cone surf which is in operation. The springs 18 have been fitt into holes formed in the side surfaces of adjacent j so that between each two jaws there are two pressure springs.

The pres-s jaws 13 can be equipped with exchangeable ing jaws (not shown in the figure). The said working jaws are equipped with quick locking parts for fasten The locking part is composed of a radial spigot inclu in the working jaw, the spigot having a groove or the like. For the said spigot there has been formed to th inner surface of the main jaw a radial boring 20, by means of which the spigot with its jaws may be made f with the aid of an axial , spring-1 oaded locking pin through hole 21 (not shown in the figure). The machin surfaces 22 of the jaws run in the ^' direction of the device's longitudinal axis.

On the outer circumference of the ring-shaped parts 7 and 8 have been formed four ear-pieces, in each of which have been made axial holes with bushed bearings 24. The holes in different rings have been linked together in pairs by means of the quidance stub axles 25. The centre axis of the guidance stub axle thus also runs in the direction of the device's longitudinal axis. The said guidance stub axles have in the middle a shoulder 26, the diameter of which is bigger than that of the actual stub axle part 25. The shoulder part acts as a distance piece between the two quiding rings 27 and 28, which have been placed externally to the outer circum erence of the ring-shaped parts and con¬ centrically in relation to the centre axis of the said parts. Rotatable discs 29 have been attached with bearings to the quiding rings 27 and 28, there being two of the said discs for each jaw. The diameter of the discs is such that they fit completely inside the guiding rings. They are thus fastened with bearings in the known manner between the said guiding rings. To the ottom of each press jaw has been fastened a guiding plate 30 in such a manner that the end of the said guid¬ ing plate is placed in the space between the guiding rings 27 and 28 at a suitable distance. The spacing between the discs 29 on the rings 27 and 28 has been selected in pairs in such a manner that they can support the guiding plate from both of the narrower sides while it moves correspondingly radially during the radial movement the press aws. The guiding plates 30 have been fastened to the bottom part of the press jaws in the centre in such a manner that a hole 31 has been bored in the press jaws, reaching to the bottom in order to form a continuation of the radial boring 20. A boring has been made in the end surface of the guiding plate so that through the said hole the guiding plate 30 can be fastened by means of a screw fastening to the lower part of the main j w.

Since the guiding rings 27 and 28 and the discs 29 to gether with the guiding plates 30 running in a radial direction have been fixed to the guiding stub axle by means of the shoulder 26, the guiding plate moves als "in a radial direction and maintains its direction dur the radial movement of the main jaw.

The operation of the introduced device for pressing tight hose couplings to the ends of pressure hoses, for example, takes place in the following way. At the commencement of the machining the device is in the position shown in Figure 4 so that the ring-shaped pa 7 and 8 are in one extreme position, that is farthest away from each other in an axial direction. Thus the inner cone surfaces 11 and 12 of the ring-shaped part and the outer cone surfaces 16 and 17 of the jaws 13 are against each other. The jaws are thus opened to their extreme position. At this stage the part to be machined is placed between the jaws from the front of the device (Figure 1). The radially projecting parts are then pushed completely past the aws so that the actual point to be machined remains in place in the jaws. Following this the horizontal power device oper ing on the ring—shaped part 8 is started so that the said part commences to move to the left in Figure 4, towards the fixed part 7 guided by the guiding rods 6. The jaws 13 start to move radially inwards under pressure from the cone surfaces 11 and 12. At this sta the rad ⁱ al movement of the jaws is .rapid, since the taper angle of the cone surfaces 11 and 12 has been selected in such a manner that the radial transition of the jaws corresponding to a certain axial approachi distance of the parts 7 and 8 is big. The cone surface 11, 12 and 16, 17 are used only for the rapid radial movement of the jaws so that they can be moved quickly and in a convenient manner near to the actual machinin posi t i on .

The actual machining takes place by using the cone sur¬ faces 9 and 10 of the ring-shaped parts and the cone surfaces 14 and 15 of the jaws 13 so that the ring- shaped part 8 moves further towards the fixed part 7, pushed by the power device. The tapering of the cone surfaces has thus been selected in such a manner that the radial transition of the jaws corresponding to the axial transition of the parts 7 and 8 is small so that the pressing force becomes large. In Figure 3 the device has been shown in the final stage of pressing. In each case the pressure springs 18 hold the interacting cone surfaces firmly in contact with each other during move¬ ment .

The guiding plates 30 which have been fastened to the bottom of the jaws on their centre line hold the jaws in their correct position during the radial movement in that they allow the radial movement of the jaws, the said plates 30 moving in a radial direction guided by the discs 29. but together with the guiding rings 27 and 28 they prevent the jaws adopting a slanting position during the movement. The guiding plates 30 remain in the direction of the radial movement of the jaws during the whole machining, though the jaws move also axially in addition to their radial movement. This is made possible by means of the shoulder 26 formed to the guiding stub axle 25. the shoulder being placed between the guiding rings. Thus the guiding plates main¬ tain their correct direction, since the stub - cle 25 is housed in bearings allowing it to move freely in its axial direction, the bearings being supported by the ears 23.

In this has been introduced only one advantageous embodi ent of the invention. The device in accordance

with the invention may be fitted for example accord¬ ing to application 772659 to a sequentially rotating disc, so that each device is adapted to perform a pres movement of different size and by which each tool can be brought into operation in turn. The guiding mech¬ anism in particular can be also realised constructivel in some other manner. For example instead of guiding plates rod-like parts can be used housed in bearings in holes radially directed in the guiding ring made in one piece.

The embodiment ^' s of the invention can vary within the attached patent claims.

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