DE2511490A1 - DEVICE FOR EXPANSION OF PIPE ENDS - Google Patents

Description

λγ .. RANS TAP

PATENT ADVOCATE

D - 605 OFFENBACH (MAIN) KAISERSTRASSE 9 FEDERAL REPUBLIC OF GERMANY

TELEPHONE (06 11) 88 27 21

March 11, 1975 Zap / Han

Ing.Edwin Rothenberger
Welding technology and industrial needs

6ooo Frankfurt am Main - 1 Heidelberger Strasse 13

"Device for expanding pipe ends"

The invention relates to a device for expanding of pipe ends, consisting of a housing and a 'therein longitudinally movably mounted mandrel with a conical End, from a concentric to the mandrel with the housing extension connected to the housing, in which several expanding jaws in the form of cylindrical sectors under the influence of the conical The end are radially displaceable and mounted protruding from the housing extension, and from one of the other end of the Doms associated eccentric whose shaft is in one of the Circular shape deviating recess of the housing in different Distances from the expanding jaws in the “way · .; is arranged lockable that a step mechanism is formed for the intermittent mandrel actuation.

609839 / ΟΓ208

Devices of the type described above are used to expand pipe ends to such an extent that a pipe end originally of the same diameter can be introduced into them. In the same way, so-called Sliding sleeves are manufactured, i.e. pipe sections that are placed between two already permanently installed pipeline parts should be used. Such a device is a hand tool, which is primarily used in heating and installation Is used. The eccentric is connected to a lever with a handle. A second lever with handle is firmly connected to the housing, so that the entire device has the shape of a Pliers has, When the lever or the handles are pressed together, the mandrel is inserted into the conical recess of the Spreading jaws pressed in and drives them apart. A pipe end located on the spreader jaws is thereby expanded by a corresponding amount. The actuation force depends on the dimensions, of the pipeline and its material properties from the opening angle of the mandrel end, from the eccentricity of the eccentric and on the lever length of the handles. These last-mentioned, structural features of the device determine the transmission ratio within the mechanical system. To the operating force, ^ ι which achieve considerable values, especially in pipelines with a large diameter or large wall thickness can be kept short, for example the lever length could be increased or the opening angle of the mandrel could be reduced be wrestled. For reasons of handling, however, there are limits to the length of the lever. A very slim end of the thorn requires a correspondingly larger mandrel stroke, which is compensated for by a greater eccentricity of the eccentric would have to be so that the apparent advantage

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is lifted. In order to make the transmission ratio more favorable, the mandrel end remains at a given opening angle and given lever length only allows you to reduce the eccentricity of the eccentric. This continues but presupposes that the eccentric drive is designed in several stages, i.e. that the eccentric shaft in the direction of the spreading jaws can be moved and locked in several positions, so that the movable one can be actuated several times Lever an intermittent actuation of the mandrel takes place.

A device of the type described above with a step mechanism is previously known from DT-OS 1,752,461. In the known solution, the recess of the housing deviating from the circular shape is replaced by one in the direction of movement of the mandrel extending slot formed in which the eccentric shaft is freely transverse to its longitudinal axis is movable. The eccentric shaft is determined in different positions by a Tab which is pivotably arranged on the eccentric shaft and engages with one or more grooves on the housing can be brought. When the tab is pivoted out, the eccentric shaft comes to the end of the slot System. As an alternative solution, a step wedge that can be inserted from the outside between the housing and the eccentric shaft is specified. however, the type of actuation is left open.

In the previously known solution, the transmission of the = _ Reaction force from the eccentric shaft on the housing via an additional component, namely the pivotable one Tab, which is referred to there as a step claw. This additional component represents the actual weak point

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of the known system. The point of contact between the tab and the grooves in the housing is subject some wear and tear. It should be noted that the tab and thus the step mechanism only at those working strokes are used in which the greatest actuation force is required, namely upon completion of the expansion process. Increasing wear of the step mechanism leads to the fact that this pops out under the influence of the operating force. In addition, especially when using the device on construction sites, there is always the risk that the dirt deposits in the hard-to-reach areas between the tab and the housing, which enables reliable locking the tab in the housing groove prevents.

The previously known device also has no return spring for the mandrel, so that the expanding jaws also ··· " when swiveling back the eccentric remain in the spread position and not easily out of the expanded position Pipe end can be removed. This is due, among other things, to a certain self-locking between the conical mandrel end and the expanding jaws.

The invention has for its object to improve a device of the initially described type in such a way that can be dispensed with an intermediate member for transmitting the reaction force from the eccentric shaft to the G _e housing and that in particular a many stages of the step mechanism is achieved, without that the susceptibility to failure increases accordingly.

The object set is achieved "according to the present invention in that the recess of the * Ge ¹ '.,

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housing has several lateral indentations, which are arranged and staggered in the direction of movement of the mandrel are designed so that the eccentric shaft with respect to the direction of the reaction force "R" into the Indentations can be used.

The graduation of the indentations shows a dimension "H" which corresponds to the eccentricity of the eccentric. The smaller the selected eccentricity, i.e. the larger the force transmission is, the more numerous are the indentations and thus the working strokes for actuating the mandrel and the expanding jaws. In the specified way a multi-stage mechanism is possible, without thereby suffering the reliability and operational safety of the device. Through the engagement of the eccentric shaft in indentations of the housing itself any kind of intermediate link for the transmission of the Reaction force avoided. The case itself has "a clean, smooth appearance with a minimum of dead corners for dirt to accumulate is. There is practically no wear because the contact surfaces of the eccentric shaft are in the indentations is relatively large. As will be shown further below, it is due to the corresponding design of the indentations possible to reliably prevent the eccentric shaft from slipping. The attachment of several abutments for the eccentric shaft in the housing itself creates the conditions for the manufacture of the housing on automatic lathes and milling machines. The housing itself is essentially "U" shaped with a central one Hole in the yoke for receiving the mandrel, the recess with the indentations by corresponding "c Milling processes can be produced in the legs.

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The arrangement of the indentations can be varied in many ways. So it is possible to alternate the indentations to be arranged on both sides of the recess, or in the surface facing away from the mandrel in one direction of movement to arrange the mandrel inclined recess. Also the distances between the individual indentations from each other can be varied in many ways.

For the purpose of a secure, form-fitting mounting of the eccentric shaft, it is recommended that the indentations in Direction of the reaction force "R" undercut by an amount "s" to train. In practice, this dimension is between about 0.5 and 2 mm. The undercut wins particular importance in connection with the arrangement of a return spring system between the housing and the mandrel. This return spring system leaves the mandrel in the starting position not only when the eccentric is pivoted back return so that the expanding jaws are released, but it also reliably presses the eccentric shaft in the undercut indentations of the recess. This creates a kind of detent, i.e. the eccentric shaft snaps reliably into the next indentation after a working stroke has been carried out and becomes held there safely.

The return spring system consists particularly expediently of at least one spring with flat characteristics for the first stroke or strokes of the mandrel and of at least one spring with steep characteristics for the last stroke. The spring or springs with flat characteristics enable the mandrel to be withdrawn for the purpose of easy insertion into the pipe to be expanded. The spring with a steep characteristic, d ^ e only at the last stroke of the ^.>

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The mandrel becomes effective enables the mandrel to be safely returned after the maximum force has been applied, and against the tendency of the mandrel to adhere to the expanding jaws. The springs of both are useful Characteristics connected in series, so that the spring with steeper, characteristic after compression the spring with flat characteristics can come into effect against a stop.

It is also advantageous to arrange a bearing bush with self-lubricating properties between the housing and the mandrel. This has the advantage that the device can last for a long time even if maintenance or lubrication is neglected Time remains fully functional. Several axially parallel bores can be arranged in the bearing bush, in which the springs with flat characteristics are located. This measure ensures a particularly good Reached the urgent construction of the device.

The device according to the invention can continue in this way be designed so that the housing extension with the expanding jaws can be exchanged and replaced by an adapter which has a punch, one end of which is provided with a recess for cooperation with the mandrel and the the other end is provided with a receptacle for a cutting, punching or embossing tool, with the adapter

a G-shaped bracket for the corresponding counter tool is appropriate. With such an adapter, the device for expanding pipe ends in a hand-operated punch or a hand-operated cutting tool can be converted, namely only by the ■ '-., Attaching a relatively simple component. This makes it universally applicable, especially on construction sites

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enables.

An embodiment of the subject matter of the invention, his Function and individual parts are explained in more detail below with reference to FIGS. 1 to 4.

Show it:

Figure 1

a partial axial section through a .. · ■ · _ complete device during an expansion process,

Figure 2

an enlarged view of the upper housing part with indentations that alternate are arranged on both sides of the recess,

Figure 3

a variant of the object of Figure 2 with indentations that run in an oblique Are arranged recess, and

Figure 4

an axial section through an adapter with a cutting, punching or embossing tool for the Device according to Figure 1.

In Figure 1, Io denotes a housing which is in is essentially rotationally symmetrical and has a thread 11 at its lower end. The case is provided with a radially protruding, lateral lever 12, which has a at its end, not shown Handle carries. In the housing Io there is a coaxial bore 13 in which a mandrel 14 is mounted so as to be longitudinally movable ο et is. The mandrel has a conical end 15, which

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protrudes from the housing Io. The other end of the thorn is provided with a head 16, the end face 17 of which with an eccentric 18 of a second lever 19 together acts, which also carries a handle at its end, not shown. Eccentric 18 and lever 19 are rotatably mounted about an eccentric shaft 2o, which is movably arranged in a recess 21 of the housing Io. The housing Io is provided with a continuous milling parallel to the plane of the drawing which the housing is approximately U-shaped. The two legs of the housing, also called bearing blocks can be designated, bear the reference numerals 22 and 23. In each of these legs there is a recess 21 arranged. When the lever 19 is actuated in the direction of the arrow 24, the mandrel 14 moves downwards into a housing extension 25, which consists of a sleeve 26 which has an internal thread which with the thread 11 cooperates. "The sleeve 26 has in lower part a pierced annular groove 27 and a bore 28, which for receiving several expanding jaws 29 serve, of which only two are visible in Figure 1. The expanding jaws have a cylindrical outer surface 3o, whereby in the position shown, the cylinder surfaces of all expanding jaws complement each other to form a cylinder. At their end lying in the interior of the sleeve 26, the expanding jaws have a flange 31 with a circumferential Annular groove in which an annular spring split on the circumference is inserted.

The expanding jaws 29 essentially form so-called sectors, the inwardly pointing edges of which are conical Recesses are provided which correspond to the end 15 of the mandrel. When inserting this end into the expanding jaws

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these are spread in the direction of the two arrows drawn, with the pushed over the spreading jaws Pipe end 33 is widened by a corresponding amount.

Between the housing Io and the mandrel 14 there is a bearing bush 34, which consists, for example, of bronze and has self-lubricating properties. The bearing bush 'is held in the position shown by a locking ring 35 and is therefore easy to replace. In the bearing bush 34 are distributed over the circumference, a plurality of axially parallel bores 36 are arranged, in which springs 37 are located with flat characteristics. An axially displaceable ring 38, which is held in the position shown ^v by means of several guide pins 39, serves as an abutment for these springs. A spring 40 with a steep characteristic, the other end of which rests on the head 16 of the dome 14, is supported on the ring 38. The springs 37 and 4o together form a return spring system which has a flat characteristic during the first stroke or during the first strokes of the mandrel 14, but a steep characteristic during the last stroke of the mandrel after the ring 38 has come to rest on the bearing bush 34 Characteristic that pulls the mandrel 14 back in each case from the spreading jaws 29, which are spread under maximum force, so that they can detach from the pipe end 33. From Figure 1 it can be seen ¹ that the individual springs of the spring system are connected in series. In order to protect the device against overloading, an adjusting screw 41 serving as a stop for the lever 19 with a lock nut 42, which is mounted in a threaded projection 43 on the lever 12, is also provided.

The ^ function of the in Figufcl. device shown * "is 5 .--

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the following: First, the eccentric shaft 2o is located in the uppermost one, shown in dashed lines and labeled 2oa Position. The head 16 of the mandrel 14 is also located in this under the action of the springs 37 and 4o Position on the eccentric 18. After a first pivoting movement of the lever 19 in the direction of arrow 24 to the The eccentric shaft in position 2oa moves the mandrel 14 downwards by a partial stroke and thereby spreads the spreading jaws 29 also by part of its radial path. When the lever 19 is moved back against the arrow 24 the mandrel 14 follows the eccentric 18 upwards. Since the expanding jaws 29, however, the pipe end 33 already have partially expanded, the mandrel 14 can be counter to the action of the springs 37 with a flat character Slightly slide down by hand so that the eccentric shaft 2o from position 2oa into the also dashed position shown 2ob can be brought. Then the game repeats itself, at the end of which the The eccentric shaft 2o can be brought into the position shown in FIG. 1 with the lever 19. The thorn 14 is here just before the lowest position and thus the expanding jaws 29 immediately before reaching their extreme position.

Details of the design of the recess 21 are explained in more detail with reference to FIG. The recess 21 has two lateral bulges 21b and 21c which are arranged alternately on both sides of the recess 2L. The bulges are arranged in a staggered manner in the direction of movement of the mandrel 14. The arrangement is made in such a way that that the (in relation to the graphic representation) upper, horizontal tangents to the book

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T, T and T have the same distances H ₁ and H from one another. These distances correspond to a partial stroke of the mandrel 14, which results from the required expansion of the pipeline, taking into account the springback. The bulges are provided on their inwardly directed, upper surface with noses 22b and 22c, due to which an undercut is created in relation to the indentations, which has the dimension "s". The undercut is aligned in the direction of the reaction force ' ¹ R "and reliably prevents the eccentric shaft from slipping or slipping out of the indentation The successive displacement of the eccentric shaft is indicated by arrows 44 and 45.

Essentially the same considerations apply to the variant according to FIG. 3, but the indentations are here 21d and 21e in a surface facing away from the mandrel 14 of a surface which runs obliquely to the direction of movement of the mandrel Recess 21 arranged. The successive displacement of the eccentric shaft 2o is indicated by the arrows 46 and 47 indicated.

In Figure 4 is designated with 48 an adapter in which an axially displaceable punch 49 is arranged, the one end is provided with a recess 5o for cooperation with the mandrel 14. For this purpose 'the Removed sleeve 26 with the expanding jaws 29 according to Figure 1 and the adapter 48 by means of the internal thread 51 with the External thread 11 of the housing Io screwed. Between

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A return spring 53 is arranged on the plunger 49 and a housing 52 of the adapter. The other end of the The mandrel is provided with an exception 54 for a punching tool 55, which has practically any cross-section may have. A C-shaped bracket 56 is also arranged on the adapter 48, the lateral projection of which is practical can be designed in any way. In this bracket is a corresponding counter tool 57 for the punching tool 55 attached. In the present case, a plate 58 is inserted into the bracket 56, into which a hole 59 is punched has been. The punched-out piece of waste is denoted by 6o. In the specified way, the expander to: expanded to a small press. It goes without saying that instead of the punching tool, a cutting or Embossing tool can occur.

In the above context, the expression "eccentric" is not intended to mean only curve shapes with exact circular geometry can be understood, but also deviations from this, i.e. cams or curve pieces of all kinds that cause the mandrel 14 to move axially during a pivoting movement about its shaft.

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Claims (11)

_ ₁₄ _ 251H90 Expectations: (1./Device for widening pipe ends, consisting of a housing and a mandrel mounted longitudinally movable therein with a conical end, from a housing extension connected concentrically to the mandrel with the housing, in which several expanding jaws in the form of cylinder sectors are under the influence of the conical end are radially displaceable and mounted protruding from the housing extension, as well as from an eccentric assigned to the other end of the mandrel, the shaft of which is arranged in a recess of the housing deviating from the circular shape at different distances from the expanding jaws in such a way that a Step mechanism for intermittent mandrel actuation is formed, characterized in that the recess (21) of the housing (lo ^ · has several lateral indentations (21b, 21c) which are staggered in the direction of movement of the mandrel (14) and are designed so that the Eccentric shaft (2o) in relation to the direction of the reaction force aft "R" can be inserted positively into the indentations. 2. Device according to claim 1, characterized in that the indentations (21b, 21c) are arranged alternately on both sides of the recess (21) (Figure 2). - 3. Apparatus according to claim 1, characterized in that the indentations (21b, 21c) in the surface facing away from the mandrel (14) to the direction of movement of the - 15 - 09839/020 $ Mandrel inclined recess (21) are arranged (Figure 3). 4. Apparatus according to claim 1, characterized in that the indentations (21b, 21c) are formed undercut in the direction of the reaction force "R" by a dimension "s". 5. Apparatus according to claim 1, characterized in that a return spring system (37, 4o) is arranged between the housing (lo) and mandrel (14). 6. Apparatus according to claim 5, characterized in that the return spring system consists of at least one spring (37) with flat characteristics for the or the first strokes of the mandrel (14) and of at least one spring (4o) with steep characteristics for the last stroke the thorn exists. 7. Apparatus according to claim 6, characterized in that the springs (37, 4o) are connected in series. 8. The device according to claim 1, characterized in that between the housing (lo) and mandrel (14) a bearing bush (34) is arranged ijiit self-lubricating properties. 9. Apparatus according to claim 8, characterized in that the bearing bush "(34) has a plurality of axially parallel bores (36) in which the springs (37) are located with flat characteristics. - 16 - 609839/0201 -Jo- 10. The device according to claim 1, characterized in that the eccentric (18) has such a curve shape that it rests flat on the end face (17) of the mandrel at the end of the stroke. 11. The device according to claim 1, characterized in that the housing extension (25) with the expanding jaws (29) is interchangeable and can be replaced by an adapter (48) which has a punch (49), one end of which is provided with a recess (5o) to interact with the mandrel (14) and the other end of which is provided with a receptacle (54) for a cutting, punching or embossing tool (55), with a C-shaped bracket (56) for the corresponding counter tool (57) on the adapter is appropriate. 509839/020 $ COPY