| JP10314852 | WORK TAIL END HOLDING DEVICE IN TENSILE BENDING DEVICE |
| WO/2009/109384 | MACHINE TOOL, IN PARTICULAR FOR RIM MACHINING |
| WO/1991/012114 | CLAMP WITH PIVOTING AND SLIDING JAWS |
BORTOLI, Renzo (Via Liviana 88, Torreglia, I-35038, IT)
CLAIMS
1. An apparatus for adapting the inside diameter of a vise for locking lengths of plastic pipe during welding, said vise (1 1) comprising opposite jaws (12), each of said jaws forming a cradle (14) for accommodating a length of pipe (15, 115) to be welded, at least one side (16) of said jaw (12) corresponding to a portion of said pipe (15, 115) that lies closest to the welding region being inclined with respect to the longitudinal axis of the cradle (14), said apparatus (10) being characterized in that it comprises, with reference to at least one jaw (17) of the vise (1 1 ), a first adapter body (17, 117) in which a first surface (18,118) for locking the pipe length (15, 115), is contoured so as to follow the shape of the cradle (14) at the at least one inclined side of said jaw (11), so as to form a locking surface which is inclined with respect to the axis of said length (15, 115), and at least one second reduction body (22, 122) in which a second surface (23, 123) for locking the pipe length (15, 115), is contoured so as to follow the circular arc-like shape of a region of the cradle (14) of said jaw (12) which is comprised between the at least one inclined side (16) and the opposite end of said cradle (14), a total locking surface, which is the sum of said first surface (18, 118) and of said second surface (22, 122) of said adapter bodies (17, 117, 22, 122), being smaller than the locking surface of said cradle (14).
2. The apparatus according to claim 1 , characterized in that said first adapter body (17, 117) is constituted monolithically by two incident portions (17a, 117a, 17b, 117b), which follow the shape of the cradle (14) at two incident sides (16) of said jaw (12) which lie transversely to the longitudinal axis of the cradle (14).
3. The apparatus according to claim 1 or 2, characterized in that said first adapter body (17) is provided with a first means (20) for reversible fixing to said at least one inclined side (16) of said vise (12), said first adapter body (17) having a part (19) for spacing from said cradle (14) and an edge which follows the shape of said cradle (14) at the at least one inclined side (16) and constitutes said first locking surface (18), said at least one second adapter body (22) having a transverse contour which is shaped like a circular sector, the inner edge of which constitutes said second locking surface (23) for the pipe length (15), said at least one reduction body (22) having a second means (24) for fixing to said cradle (14).
4. The apparatus according to claim 3, characterized in that said first reversible fixing means (20) comprises screws which are arranged in corresponding through holes formed at the ends of said first adapter body (18), said screws engaging corresponding holes provided in said at least one inclined side (16), said second fixing means (24) comprising at least one groove (25), which is provided in said cradle (14) along a plane which is perpendicular to the longitudinal axis of said cradle (14) and in which (25) said second body (22) is inserted edgeways, and two screws (26) that engage at the ends of said at least one groove (25) to lock in an undercut configuration the end corners of the circular sector which forms said second adapter body (22). 5. The apparatus according to claim 1 or 2, characterized in that it comprises an adapter member (112) to be fixed , reversibly to said cradle (14), said adapter member (112) having a base (129) for spacing from said cradle (14) for an additional cradle (114) for locking the pipe length (1 15) which follows the shape of the cradle (14) formed in the jaw (12), said adapter member (112) having a corresponding inclined side (116) which follows the shape of the at least one inclined side (16) of the jaw (12), said first reduction body (117) having a first means (120) for reversible fixing to said at least one additional inclined side of said adapter member (112), said first adapter body (17) having a part (119) for spacing from said additional cradle (114) and an edge which follows the shape of said additional cradle (114) at the additional at least one inclined side (116) and constitutes said first locking surface (1 18), said at least one second adapter body (122) having a transverse contour shaped like a circular sector, the internal edge of which constitutes said second surface (123) for locking the pipe length (115), said at least one second adapter body (122) having a second means (124) for reversible fixing to said additional cradle (114). 6. The apparatus according to claim 5, characterized in that said first reversible fixing means (120) comprises screws which are arranged in corresponding through holes provided at the ends of said first adapter body (117), said screws being suitable to engage corresponding holes provided in said at least one additional inclined side (116), said second fixing means (124) comprising at least one groove (125) which is formed in said additional cradle (114) along a plane which is perpendicular to the longitudinal axis of said additional cradle (114), in which (125) said second body (122) is inserted edgeways, and two screws (126), which engage at the ends of said at least one groove (125) to lock in an undercut configuration the end corners of the circular sector which forms said second adapter body (122). 7. The apparatus according to one of claims 5 or 6, characterized in that said adapter member (112) has a semicylindrical portion (101) which is contoured so as to form said additional cradle (1 14) and at least two ribs (102) shaped like a circular sector, which are welded at right angles to said semicylindrical portion (101) on the face to be directed toward the respective jaw (12). 8. The apparatus according to one or more of claims 5, 6 and 7, characterized in that said adapter member (112) has corresponding additional incident inclined sides (116), which follow the shape of said inclined sides (16) of the jaw (12).
9. The apparatus according to one or more of the preceding claims, characterized in that said first adapter body (17, 117) and said at least one second adapter body (22, 122) are made of metal plate and the respective locking surfaces (18, 118, 23, 123) are provided by the thickness of said metal plate.
10. The apparatus according to claim 9, characterized in that the edge of said first adapter body (17, 117) that provides said first surface (18, 118) is contoured so as to follow, substantially along all of its extension, the surface of said pipe length (15, 115). 11. The apparatus according to one or more of the preceding claims, characterized in that the first locking surface (18, 118) of said first adapter body (17, 117) and/or the second locking surface (23, 123) of said at least one second adapter body (22, 122) are knurled. |
APPARATUS FOR ADAPTING THE INSIDE DIAMETER OF A VISE FOR LOCKING PLASTIC PIPES
The present invention relates to an apparatus for adapting the inside diameter of a vise for locking plastic pipes during welding in order to provide T-unions, cross-pieces, Y- unions and the like.
Currently, several welding machines are commercially available for welding, by butt fusion, plastic pipes which, cut appropriately with certain inclinations and joined to each other, provide bends, T-unions, crosspieces, forked pipes (Y-unions), et cetera.
Those unions are then used in the construction site to provide piping of various kinds.
Currently, depending on the type of union to be provided, welding machines use die-cast vises made of aluminum alloy or steel vises made from calendered and welded plates and/or in some cases obtained directly from a steel pipe.
Since welding machines must have a certain operating range, adapters are provided for reducing the inside diameter of the vises.
Those adapters are generally constituted by a single part made of aluminum and are shaped like a circular sector, in order to allow a concentric arrangement within the vise. For example an adapter unit for pipes having a diameter of 200 mm is contained within the concentric adapter unit for pipes having a diameter of 225 mm, which in turn is contained within a concentric adapter unit with a diameter of 250 mm.
The locking vises are constituted by mutually opposite jaws. Each jaw has a cradle for accommodating a corresponding portion of an ordinary length to be welded.
The internal surfaces of the cradle are in practice the surfaces for locking the pipe length and are usually broad and continuous. According to the prior art, the adapters have a shape which duplicates the shape of the base vise.
If the vises are used to manufacture unions, one end of the length is generally cut at an angle with respect to the axis of the pipe. Usually the end has two incident portions cut at an angle with respect to the axis of the pipe in order to provide crosspieces, T- unions, Y-unions et cetera, and a single inclined portion for elbows, bend lengths, et
cetera for mating with one or more complementary lengths.
When two pipe lengths previously cut at an angle are butt-welded, the faces to be welded no longer appear as rings but are full or partial ellipses, caused by the double transverse cut. The thrust applied during welding therefore has a component which is transverse to the axis of the pipe, consequently reducing the axial component.
Therefore, it is important to contrast both the transverse thrust and the axial thrust by maintaining correct support of the pipe.
An adapter must therefore achieve the dual purpose of supporting the pipe up to the end and of ensuring the necessary locking of the length in order to avoid slippage.
To provide this dual function, conventional adapters duplicate the shape of the locking surface of the base vise.
The prior art adapters described above have some significant drawbacks.
Since the configuration of the adapter is similar to that of the base vise, its dimensions and weights influence the manufacturing costs because a large amount of expensive raw material, i.e. aluminum, is required, and because of the handling of the adapter which sometimes can be difficult due to the dimensions of the unions to be provided.
Also, all the adapter units of the diameters that are larger than the one required for welding are inserted in the vise when welding the smallest diameter comprised within the operating range of the welding machine, in such configuration the welding machine must withstand considerable loads. For that reason, an oversizing of the supporting structures of welding machines is necessary, with a consequent cost increase.
Also, a considerable investment is required in order to provide the dies needed to cast the adapter units.
In the type of vise constituted by calendered steel plate subsequently welded so as to form the same shape as the cradle, of the type described previously, there are no adapter units but in practice there are many vises of different diameters, one for each work diameter. An inconvenience of such method of locking the pipes, is that the entire series of
vises having different diameters which are not used during welding occupy considerable space. In addition, there is the limited practicality that derives from preparing the machine every time it is necessary to change diameter.
The aim of the present invention is to provide an apparatus for adapting the inside diameter of a vise for locking plastic pipes that overcome the problems described above.
Within the scope of this aim, an important object of the present invention is to provide a lightweight apparatus which is at the same time effective in locking the pipe length being welded.
Another important object of the present invention is to provide a structurally simple apparatus for adapting.
Another object of the present invention is to provide an apparatus which is easy to use.
This aim and these and other objects which will become better apparent hereinafter are achieved by an apparatus for adapting the inside diameter of a vise for locking lengths of plastic pipe during welding, said vise comprising opposite jaws, each of said jaws forming a cradle for accommodating a length of pipe to be welded, at least one side of said jaw corresponding to a portion of said pipe that lies closest to the welding region being inclined with respect to the longitudinal axis of the cradle, said apparatus being characterized in that it comprises, with reference to at least one jaw of the vise, a first adapter body in which a first surface for locking the pipe length, is contoured so as to follow the shape of the cradle at the at least one inclined side of said jaw, so as to form a locking surface which is inclined with respect to the axis of said length, and at least one second adapter body in which a second surface gion of the cradle of said jaw which is comprised between the at least one inclined side and the opposite end of said cradle, a total locking surface, which is the sum of said first surface and of said second surface of said adapter bodies, being smaller than the locking surface of said cradle.
Further characteristics and advantages of the invention will become better apparent from the description of a preferred but not exclusive embodiment thereof, illustrated by way of non-limiting example in the accompanying drawings, wherein: Figure 1 is a perspective view of the lower jaw of a vise showing the first adapter
stage of the apparatus according to the invention; Figure 2 is a top view of the jaw of Figure 1 ;
Figure 3 is a perspective view of the lower jaw of the vise showing a third adapter stage of the apparatus according to the invention; Figure 4 is a perspective exploded view of the apparatus of the preceding figures, illustrating the first, second and third stages from the rear;
Figure 5 is a perspective view of a complete vise, showing the third stage of the apparatus of the preceding figures;
Figures 6 to 10 respectively illustrate a Y-union, an elbow, a bend formed by lengths of pipe, a crosspiece and a T-union.
With reference to the above figures, an apparatus for adapting the inside diameter of a vise for locking plastic pipes during welding to provide T-unions, crosspieces, Y- unions and the like according to the invention is generally designated by the reference numeral 10. The apparatus is applied for example in a vise 1 1 (visible as a whole in Figure 5) which is constituted by mutually opposite jaws 12; the lower jaw is shown in Figure 1.
The lower and upper jaws, as well as the corresponding adapters, are substantially symmetrical.
Each jaw 12 has a base structure 13 on which a cradle 14 for accommodating the length 15 of pipe to be welded is provided.
The cradle 14 has a semicylindrical shape, in transverse cross-section, so as to match the outer shape of the pipe length.
The radius of curvature of the cradle 14 corresponds to the maximum half- diameter of the pipe lengths that can be used with the vise. As can be seen, in this embodiment, the vise 11 is of the type in which the end that corresponds to the locking of the portion of pipe length 15 that lies closest to the welding region has two sides 16 which are incident and inclined (and therefore arranged transversely) with respect to the longitudinal axis of the cradle 14; the sides 16 therefore have a profile shaped like two elliptical portions. The vise 1 1 allows the locking of a length of pipe in a welding machine for
providing Y-unions (also known as tees), as shown in Figure 6.
The apparatus 10 in practice is constituted by different adapter stages.
A first adapter stage (shown in Figures 1 , 2 and 4) includes, with reference to a corresponding jaw 12 of the vise 11 , a first adapter body 17, in which the surface for locking the pipe length, designated as first surface 18, is contoured so as to follow the shape of the cradle at the two inclined sides 16 of the jaw 12, so as to form a locking surface whose longitudinal plane is inclined with respect to the axis of the length 15. The first adapter body 17 is constituted monolithically by two mutually incident portions 17a and 17b, which follow the shape of the cradle at the two inclined sides 16 (and therefore has a profile which forms two elliptical portions which are smaller than the profile of the cradle 14 in the corresponding region).
The first adapter body 17 is made of suitably shaped metal plate and has a part 19 for spacing from the cradle 14 (providing in this manner the reduction in diameter with respect to the cradle) and an edge which follows, as mentioned, the shape of the cradle 14 at the inclined sides 16 and thus coincides with the first surface 18. In practice, since the two portions 17a and 17b of the first reduction body 17 are not perpendicular to the axis of the pipe length 15 to be welded (and of the cradle 14), the edge of the first adapter body 17 that provides the first surface 18 is contoured, for example machined by milling, so as to follow, along its entire extension, the surface of the length 15 (in this manner, one prevents the length from resting only along a "line" constituted by the inner edge of the first adapter body 17).
In order to fix the first adapter body 17 to the inclined sides 16, there is a first reversible fixing means 20 which is constituted for example by screws which are arranged in corresponding through holes provided in the first body at the ends of the portions 17a and 17b and in the region connecting the two portions. The screws engage in corresponding holes provided in the inclined sides 16.
The first adapter stage also includes a second adapter body 22, in which the surface for locking the pipe length 15, designated as second surface 23, is shaped so as to follow the circular arc-like shape of a region of the cradle 14 which is comprised between the inclined sides 16 and the opposite end of the cradle.
The adapter body 22 is made of metal plate and has a transverse contour shaped like a circular sector in which the inner edge constitutes the second surface 23 for locking the pipe length 15.
The second adapter body 22 is fixed to the cradle 14 by a second fixing means 24, which is constituted for example by a groove 25, which is provided in the cradle along a plane which is perpendicular to the longitudinal axis of the cradle and in which the second body 22 is inserted edgeways, and by two screws 26, which engage at the ends of the groove 25 and lock in an undercut arrangement the end corners of the circular sector which forms the second adapter body 22. As can be seen in the figures, an additional groove 27 is also provided on the cradle 14, is parallel to the groove 25, is formed at the opposite end of the cradle with respect to the inclined sides 16, and allows to use an additional second adapter body, which is parallel to the one described so far or the insertion thereof in a position which lies further back with respect to the welding region and is useful for example in the case of rather long pipe lengths.
The overall locking surface, which is the sum of the first surface 18 and of the second surface 23 of the adapter bodies 17 and 22, is smaller than the locking surface of the cradle 14 but more than sufficient to ensure the necessary locking of the length during welding. In order to ensure the grip of the vise on the pipe length, both the first locking surface 18 of the first adapter body 17 and the second locking surface 23 of the second adapter body 22 are knurled.
As mentioned, in this embodiment the first adapter body has two portions which are inclined with respect to the axis of the cradle, are mutually incident and are suitable to allow the locking of the pipe length at the portion that lies proximate to the welding region, in order to allow the application to vises for locking lengths which will compose for example a Y-union, designated in Figure 6 by the reference sign R1 , a crosspiece, designated in Figure 9 by the reference sign R2, or a T-union, designated by the reference sign R3 in Figure 10. it is evident that if the vise can be used to lock lengths which will compose for
example the elbow shown Figure 7 and designated by the reference sign R4 or a bend R5 (shown in Figure 8), in which each length R5a which forms the bend must have an end with a single cut which is inclined with respect to its own axis, the vise has a single side which is inclined with respect to the axis of the cradle and therefore the first adapter body is composed of a single straight portion.
A second adapter stage of the apparatus 10 (shown in Figures 3, 4 and 5) provides for an adapter member, designated by the reference numeral 1 12, which is to be reversibly fixed on the cradle 14 and has a base 129 for spacing from the cradle 14 for an additional cradle, designated by the reference numeral 1 14, for locking a pipe length which has a smaller diameter than the one which can be locked on the cradle 14 or in the first adapter stage. The additional locking cradle 1 14 follows the shape of the cradle 14 formed in the jaw 12.
The adapter member 1 12 has, like the jaw 12, corresponding additional inclined sides 1 16 which are incident and follow the shape of the inclined sides 16 of the jaw 12. The adapter member 1 12 is made from metal plate and has a semicylindrical portion 101 which is contoured so as to form the additional cradle 1 14 and three ribs 102 shaped like a circular sector which are welded at right angles to the portion 101 on the face to be arranged toward the respective jaw 12.
As in the first described stage, there is a third adapter stage related to the corresponding member 1 12 of a jaw 12 which includes a first adapter body 1 17 which has a first reversible means 120 (described hereinafter) for fixing to the additional inclined sides 1 16 of the adapter member 112.
Figure 5 shows a complete vise with the third adapter stage for a pipe length 115 associated therewith. The locking surface of the first adapter body 1 17, designated as first surface 1 18, is contoured so as to follow the shape of the additional cradle 114 at the two additional inclined sides 1 16 of the adapter member 1 12 (and therefore at the two inclined sides 16 of the jaw 12), so as to form a locking surface whose plane of extension is inclined with respect to the axis of the pipe length being locked 115 (which has a smaller diameter; as for the first stage, the first adapter body 1 17 is constituted monolithically by two portions
1 17a and 1 17b which are mutually incident and follow the shape of the additional cradle 1 14 at the two additional inclined sides 1 16 (and therefore has a profile shaped like two portions of an ellipse which are smaller than the profile of the additional cradle 114 in the corresponding region). As described previously, the first adapter body 1 17 is made of contoured metal plate and has a part 1 19 for spacing from the additional cradle 1 14 (thus providing the reduction in diameter with respect to the additional cradle) and an edge which follows, as mentioned, the shape of the additional cradle 1 14 (and therefore of the cradle 14) at the additional inclined sides 1 16 and thus coincides with the first surface 1 18. The first reversible fixing means 120 is constituted for example by screws which are arranged in corresponding through holes provided in the first body at the ends of the portions 1 17a and 1 17b and in the joining region of the two portions. The screws engage in corresponding holes provided in the additional inclined sides 116.
As in the first adapter stage, the third adapter stage has a second adapter body 122, in which the surface for locking the pipe length 1 15, designated as second surface 123, is contoured so as to follow the circular arc-like shape of a region of the additional cradle 1 14 (and therefore of the corresponding region of the cradle 14 of the vise 12) which is comprised between the two additional inclined sides 1 16 and the opposite end of the additional cradle. The second adapter body 122 is made from metal plate and has a transverse contour shaped like a circular sector, the inside edge of which constitutes the second surface 123 for locking the pipe length 1 15.
The second adapter body 122 is fastened to the additional cradle 14 by a second fixing means 124 which is constituted, as in the first stage, for example by a groove 125, which is provided in the additional cradle along a plane which is perpendicular to the longitudinal axis of the cradle and in which the second body 122 is inserted edgeways, and by two screws 126, which engage at the ends of the groove 125 and lock in an undercut arrangement the end corners of the circular sector which forms the second adapter body 122. As can be seen in the figures, an additional groove 127 is also provided on the
additional cradle 114, is parallel to the groove 125, is formed at the opposite end of the additional cradle with respect to the inclined sides 116, and allows to use an additional second adapter body which is parallel to the one described so far or to insert it in a position which lies further back with respect to the welding region, which is useful for example in the case of rather long pipe lengths.
The overall locking surface, which is the sum of the first surface 118 and of the second surface 123 of the adapter bodies 117 and 122, is smaller than the locking surface of the additional cradle 114 but more than sufficient to ensure the necessary locking of the length during welding, The apparatus is composed substantially of three adapter stages.
A first adapter stage covers a range of diameters comprised between the maximum diameter of the pipe length that can be accommodated on the cradle 14 of the jaw of the vise and a minimum diameter which can be provided by the internal radius of the second adapter body to be arranged on the cradle (and an equivalent shaping of the edge of the first adapter body). The first stage can include a first series of adapter bodies, which are useful to allow a variability in diameter comprised between the maximum diameter and the minimum diameter.
A second adapter stage is constituted by the additional cradle formed by the adapter member, which in practice matches the structure of the base jaw and allows to lock a given intermediate diameter of the pipe length which is smaller than the maximum diameter of the range of useful diameters of the first stage.
A third adapter stage is formed by reduction bodies which are similar to those of the first stage which are fixed to the adapter body.
In practice it has been found that the invention thus described solves the problems of the cited prior art adapter for pipe locking vises. In particular, the present invention provides an apparatus which is particularly lightweight.
Indeed, after a series of studies it has been physically verified that, in order to keep the plastic pipe length prepared for angle welding locked, it is not necessary to use contoured solid reduction units such as the ones of the prior art, but it is possible for only some portions of the lengths to be supported and locked.
It has in fact been verified that the two adapter bodies formed by metal plates of suitable thickness, mounted on the front and rear part of the vise, can reproduce a condition of support and clamping of the pipe length equal to a solid monolithic adapter unit with the same capacity to recover any ovalization that is present thereon in the welding region.
The saving of material is evident, with a consequent reduction in weights (and costs) and easier handling of the operations related to welding.
Since the second adapter body has a given shape to lock a "straight" pipe length, it can be used conveniently in vises which have a different contour to provide different shapes of unions.
The introduction of the adapter member is useful when, for certain welding machines, the contact of the pipe length on the second reduction body fixed directly to the jaw is not ensured.
The use of the adapter member also allows other advantages, such as for example the fact of being able to use the adapter bodies on vises of welding machines which have different work ranges, with evident reductions in the industrialization and management costs of the apparatus.
In general, therefore, the present invention achieves the following advantages.
First of all, production costs are reduced by virtue of the lower cost due to the use of a material (steel) which is cheaper than aluminum.
Production costs are also reduced by virtue of the fact that the investments linked to the dies to provide the aluminum castings are eliminated.
The production method is also extremely simple. It consists in laser-cutting steel plates to provide adapter bodies which are suitably shaped like a circular arc and in connecting the bodies. The method is cheaper than the production of adapter units obtained from monolithic castings.
Costs are also reduced and the management of the apparatus (the second adapter body) can be reused on many vises.
This apparatus also provides easier changing of the adapter units, with an increase in production rate.
A smaller overall space occupation of the components of the apparatus that are not used is achieved since the components are small (and can also be stacked).
Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.
This application claims the priority of Italian Patent Application No. PD2006A000357, filed on September 26, 2006, the subject matter of which is incorporated herein by reference.