WO2021064672A1

WO2021064672A1 - Device and method for assembling a fitting

Info

Publication number: WO2021064672A1
Application number: PCT/IB2020/059266
Authority: WO
Inventors: Nicola PELATI; Luca GATELLI
Original assignee: Abl Automazione S.R.L.
Priority date: 2019-10-04
Filing date: 2020-10-02
Publication date: 2021-04-08

Abstract

The device and the method according to the invention make it possible to mount a sealing ring (4) and, at the same time, a back-up ring (6) in a body seat (14) of a fitting body (2) of a fitting (1), by stretching together said rings (4, 6) before inserting them into the fitting body, remaining within the elastic behavior limits and reducing the maximum overall dimensions thereof, and then releasing them in the body seat (14).

Description

"DEVICE AND METHOD FOR ASSEMBLING A FITTING"

DESCRIPTION

[0001]The present invention relates to the sector of assembling machines and relates, in particular, to a device for assembling an O-ring and an anti-extrusion ring in a fitting.

[0002]There are many types of fittings, which differ by type of use (e.g. for gas distribution systems or plumbing systems), functions, materials (they can be made of plastic, brass, steel, to name but a few), shape, size. Millions of pieces are manufactured every year.

[0003]Therefore, manufacturers are faced with the need to manufacture high volumes while maximizing the profit margin and are thus constantly striving to reduce manufacturing costs. Among the most important costs, there are certainly those related to the assembling of some components to the body of the fitting to make the finished product.

[0004]In particular, the assembling of an O-ring and its anti-extrusion ring in an inner seat of the body is very often still done manually, with drawbacks also on the finished product quality.

[0005]It is the object of the present invention to create a assembling device for assembling an O-ring and its respective anti-extrusion ring in a fitting, able to meet the automation needs of the sector and, at the same time, overcome the aforesaid drawbacks.

[0006]Such an object is achieved by a assembling device according to claim 1. The dependent claims describe further advantageous embodiments.

[0007]The features and advantages of the assembling device to the present invention will be apparent from the following description, given by way of non-limiting example, with reference to the accompanying figures, in which:

- figure 1 shows an embodiment of a fitting with separate parts; figure 2 shows a longitudinal section view of the fitting in figure 1; - figures 3a to 3d show a assembling device according to the present invention, according to a preferred embodiment, in an initial configuration; figures 4a to 4d show the assembling device in a pulling configuration; - figures 5a to 5d show the assembling device in a positioning configuration; and figures 6a to 6d show the assembling device in an inserting configuration.

Description of the fitting [0008]For clarity of presentation, reference will be made hereinafter to a fitting having the features shown in figures 1 and 2; the present invention, however, is applicable to a generic fitting.

[0009]The fitting 1 comprises a fitting body 2, e.g. in one piece, e.g. made of brass, an O-ring or sealing ring 4, and an anti-extrusion ring or back-up ring 6.

[0010]The sealing ring is generally made of NBR (Nitrile Rubber), silicone, fluorocarbon rubber, EPDM (Ethylene- Propylene Diene Monomer); the back-up ring is generally made of PTFE (Polytetrafluoroethylene), EPDM, TPE

(Thermoplastic Elastomers), NBR 90 Shore A. In any event, either for the material features or the geometrical or constructive features, the sealing ring 4 displays a different elasticity from that of the back-up ring 6, and in particular the back-up ring is more rigid than the sealing ring, to work as an anti-extrusion ring.

[0011]The body 2, internally hollow, comprises an annular body wall 8, which extends between a first opening 10 and a second opening 12, along a body axis X, e.g. straight. [0012]The body 2 has an annular inner body seat 14, which is obtained in the body wall 8 to house the sealing ring 4 and the anti-extrusion ring 6; the body seat 14 has a bottom diameter Dsc.

[0013]The body seat 14 is axially delimited between a first seat ridge 16, proximal to the first opening 10 and having a first ridge diameter Dpr, and a second seat ridge 18, proximal to the second opening 12.

[0014]For example, the sealing ring 4 and the back-up ring 6, having an outer diameter substantially equal to the body seat diameter Dsc, enter into the fitting body 2 through the first opening 10 and are arranged in the body seat 14; according to an embodiment, the first seat ridge 16, having a smaller first ridge diameter Dpr than the body seat diameter Dsc (Dpr<Dsc), is provided with a chamfer 20, which creates a lead-in to enter into the body seat 14.

Description of the assembling device

[0015]According to a preferred embodiment of the invention, a assembling device 100 comprises a base 102, which supports, e.g. by means of a rear support 103, a fixed stop 104 with prevailing extension along a fixed axis Z between a front end 106 and a rear end 108.

[0016]At the front end, the fixed stop 104 carries a stop head 110 enlarged relative to the remaining part of the fixed stop 104, having a head diameter Dt smaller than the first stop diameter Dpr of the fitting 1.

[0017]The fixed stop 104 has an axial groove 112 at the top which reaches the front end 106, creating a gap 114 in the stop head 110. [0018]The assembling device 100 further comprises a first slider 120, coupled to the fixed stop 104 on the upper part thereof and sliding on command, e.g. in the groove 112.

[0019]At the front, the first slider 120 has a slider hook 122, e.g. corresponding to the end portion of the first slider, which preferably mimics the shape of the stop head 110, to complete it when said slider hook 122 is in the gap 114.

[0020]The first slider 120 can be commanded in translation between a limit advanced position, in which the slider 122 is near the front end 106 of the fixed stop 104, e.g. aligned with the front end 106 of the fixed stop 104, and in particular with the stop head 110, and a backward limit position. [0021]For this purpose, the assembling device 1 comprises first slider actuating means, e.g. pneumatic ones.

[0022]According to an embodiment, said first slider actuating means comprise a first connection 124 and a first actuator 126, offset and parallel relative to the stop axis Z, preferably supported by a first support 128, supported, in turn, by the base 102; the first connection 124 is fixed to the first slider 120 and the first actuator 126.

[0023]Preferably, said actuating means comprise a first abutment 130, which determines the limit advanced position of the first slider 120, against which the first connection 124, for example, abuts.

[0024]The assembling device 1 further comprises a second slider 140, which is coupled to the fixed stop 104 at its lower part and slides on the surface of the fixed stop, e.g. on the surface of the fixed stop 104.

[0025]The second slider 140 has a thrust portion 140a at the front, e.g. corresponding with a front end section. [0026]The second slider 140 can be commanded in translation between a limit advanced position, in which it is proximal to the front end 106 of the fixed stop 104, and in particular to the stop head 110 and a retracted limit position.

[0027]For this purpose, the assembling device 1 comprises second slider actuating means, e.g. pneumatic.

[0028]According to an embodiment, said second slider actuating means comprise a second connection 142 and a second actuator 144, offset and parallel to the axis Z, e.g. on the opposite side to the first actuator 126. [0029]The second actuator 144 is preferably supported by a second support 146, supported, in turn, by the base 102; the second connection 142 is fixed to the second slider 140 and the second actuator 144.

[0030]Preferably, said actuating means comprise a second abutment 148, which determines the limit advanced position of the second slider 140, against which the second connection 142, for example, abuts.

[0031]The assembling device 100 further comprises a guide wall 152, arranged radially outside the fixed stop 104, near the front end 106, ending axially upstream of said front end 106. The guide wall 152 is suitable for being inserted into fitting body 2 through the first opening 10.

[0032]Furthermore, the guide wall 152 circumferentially delimits a chamber 150 around the fixed stop 104, through which the first slider 120 and the second slider 140 pass.

[0033]The assembling device 1 further comprises a stop body 154 suitable for creating an axial abutment for fitting body 2 inserted on the guide wall 152.

[0034]Preferably, the guide wall 152 and the body stop 154, protruding radially from the outside of the guide wall 152, are parts of a bushing 160, crossed by the fixed stop 104, the first slider 120, and the second slider 140.

[0035]Preferably, said bushing 160, made in one piece, is supported by a front support 170, supported, in turn, by the base 102.

[0036]Finally, the assembling device 100 comprises electronic control means, e.g. comprising an electronic card or microchip, operationally connected to the first slider and, if necessary, to the second cursor, by means of said actuating means, and configured, for example by programming, for executing the operation specified below. Description of operation

[0037]In normal operation, in a first configuration of assembling device 1 (initial configuration), the first slider 120 is in the limit advanced position, and preferably the second slider 140 is in the limit retracted position (figures from 3a to 3d).

[0038]In such configuration, the slider hook 122 of the first slider 120 forms a ring seat 200 with the stop head 110 of the fixed stop 104, in which seat the sealing ring 4 and the back-up ring 6, hanging at the front end 106, are positioned.

[0039]In a second configuration (pulling configuration), subsequent to the first configuration mentioned above, the first slider 120 is in the limit retracted position, in which the slider hook 122 is behind the pushing portion 140a of the second slider 140 (figures from 4a to 4d).

[0040]In the passage from the initial configuration to the pulling configuration, an upper stretch of the rings 4, 6 is engaged with the stop hook 122, so that the rings 4, 6 are pulled inside the chamber 150. [0041]When the first slider 120 reaches the limit retracted position, a lower stretch of the rings 4, 6 abuts against the thrust portion 140a of the second slider 140, so that the rings 4, 6 are stretched between the stop hook 122 and the thrust portion 140a of the second slider 140, adhering also to the side surface of the fixed stop 104.

[0042]In such configuration, the relative axial position between the stop hook 122 and the thrust portion 140a is defined so that the two rings 4, 6 are elastically deformed so that they can return to their original state. [0043]Subsequently, the fitting body 2 of the fitting 1 is inserted, by an operator or an automatic system, onto the guide wall 152 through the first opening 10 and brought to the stop of the stop body 154.

[0044]The front end 106 of the fixed stop 104 is located downstream of the body seat 14, i.e. on the other side of the body seat 14 relative to the opening 10; the thrust portion 140a of the second slider 140 is instead located upstream of the body seat 14, as is the slider hook 122 of the first slider 120.

[0045]In a third configuration (positioning configuration), the second slider 140 is preferably in the limit advanced position, so that the 140a thrust portion is substantially aligned axially with the first seat ridge 16 of the fitting body 2 or even inside said seat body 14.

[0046]In any event, the position taken by the second slider 140 is suitable for releasing the rings 4, 6 in the body seat 14.

[0047]Preferably, the first slider 120 is also actuated, preferably at the same time as the second slider 140, so that the slider hook 122 approaches the body seat 14, while remaining upstream of the thrust portion 140a. Advantageously, this avoids a breakage or plastic deformation of the rings 4, 6.

[0048]In a fourth configuration (inserting configuration), the first slider 120 is in the limit advanced position, in which the slider hook 122 is downstream of the body seat 14, substantially aligned with the stop head 110

(figures from 6a to 6d).

[0049]In such arrangement, the rings 4, 6 take the shape of the original state and occupy the space allocated to them in the body seat 14, disengaging the first slider 120, the second slider 140, and the fixed stop 104.

[0050]The fitting 1 can thus be removed from the guide wall 152; the assembling device 100 is now back in its initial configuration, ready for assembling an additional fitting . [0051]In other words, according to the assembling method of the present invention, the rings 4, 6 are stretched together, before the insertion into the fitting body, remaining within the limits of elastic behavior, to reduce their maximum dimensions, and are then released into the body seat.

Other variants

[0052]The assembling device and operation described above refer to a preferred embodiment.

[0053]According to a variant embodiment, which can be made as a function of the resistance of the rings 4, 6 and the elastic behavior limit, the assembling device is provided with a second fixed slider, while the first slider pulls the rings and releases them into the body seat.

[0054]According to a further variant of embodiment, the assembling device is without a fixed stop.

[0055]According to a yet further variant of embodiment, the assembling device and method can be used to mount only one ring, e.g. only the sealing ring or only the back-up ring, or to mount one them in sequence one after the other.

[0056]Conclusions

[0057]Innovatively, the assembling device according to the present invention meets the needs of the sector because it makes it possible to automate the assembling of the sealing ring and of the back-up ring inside a fitting. [0058]Furthermore, the invention advantageously makes it possible to install the sealing ring and the back-up ring at the same time, thus reducing the overall production time. [0059]It is apparent that a person skilled in the art may make changes to the assembling device and method described above, all of which are contained within the scope of protection as defined in the appended claims to satisfy contingent needs.

Claims

1. A method for assembling a sealing ring (4) and, at the same time, a back-up ring (6) in a body seat (14) of a fitting body (2) of a fitting (1), comprising the steps of stretching together said rings (4,6) before inserting them into the fitting body, remaining within the limits of an elastic behavior, in order to reduce the maximum overall dimensions thereof, and then releasing them in the body seat (14).

2. A method according to claim 1, wherein the sealing ring (4) exhibits an elasticity different from the back up ring.

3. A method according to claim 2, wherein the back-up ring is stiffer than the sealing ring.

4. A assembling device (100) for assembling a sealing ring (4) and, at the same time, a back-up ring (6) in a body seat (14) of a fitting body (2) of a fitting (1), comprising:

- a fixed body stop (154) for the fitting body (2); - a first slider (120) provided with a slider hook (122) suitable to hook said rings (4,6), movable on command between a limit advanced position and a limit retracted position;

- a second slider (140) provided with a thrust portion (140a) suitable for pushing said rings (4,6); - electronic control means operationally connected to the first slider (120), configured so that a) in an initial configuration, the first slider (120) is in the limit advanced position and the rings (4,6) are suspended on the slider hook (122); b) in a subsequent loading configuration, the first slider (120) is in the limit retracted position, so that the rings (4,6) are pressed between the slider hook (122) and the thrust portion (140a), remaining within the limits of an elastic behavior; c) in a subsequent insertion configuration, the first slider (120) is in the limit advanced position, so that the rings (4,6) are released into the body seat (14).

5. A assembling device according to claim 4, wherein: - the second slider is movable on command between a limit advanced position and a limit retracted position, close to the body stop (154) with respect to the limit retracted position of the first slider (120);

- electronic control means are operationally connected also to the second slider (140), configured so that

(d) in a positioning configuration subsequent to the loading configuration and prior to the insertion configuration, the second slider (140) is in a limit advanced position suitable for releasing the rings in the body seat (2).

6. A assembling device according to claim 5, wherein in said positioning configuration, the first slider (120) is in a position downstream of the limit retracted position of the first slider (120), but upstream of the limit advanced position of the second slider (140).

7. A assembling device according to any one of claims 4 to 6, wherein in said initial configuration, the second slider (140) is in the limit retracted position.

8. A assembling device according to any one of claims 4 to 7, comprising a fixed stop (104) having a predominant extension along a fixed axis (Z) between a front end (106) and a rear end (108) wherein the first slider (120) is coupled with the fixed stop (104) in the upper part thereof and the second slider (140) is coupled with the fixed stop (104) in the lower part thereof.

9. A assembling device according to claim 8, wherein the fixed stop (104) has an axial groove (112), within which the first slider (120) is slidable.

10. A assembling device according to claim 9, wherein at the front end (106) the fixed stop (104) comprises an enlarged stop head (110), the groove (112) reaches the front end (106) creating a gap (114) in the stop head (110) and the stop hook (122) of the first slider (120) takes the shape of the stop head (110), so as to complete it when said slider hook (122) is in the gap (114), thus forming a ring seat (200) to suspend said rings (4,6).

11. A assembling device according to any one of the claims 4 to 10, comprising a guide wall (152) suitable to be inserted into the fitting body (2) to guide it in abutment against said body stop (154).

12. A assembling device according to claim 11, wherein said guide wall (152) circumferentially delimits a chamber (150) around the fixed stop (104), through which the first slider (120) and the second slider (140) pass.

13. A method for assembling a sealing ring (4) and, at the same time, a back-up ring (6) in a body seat (14) of a fitting body (2) of a fitting (1), by means of a assembling device (100) according to any one of claims 4 to 12.

14. A method for assembling a sealing ring (4) or a back up ring (6) in a body seat (14) of a fitting body (2) of a fitting (1), comprising the steps of stretching said ring (4,6) before inserting it into the fitting body, remaining within the limits of an elastic behavior, in order to reduce the maximum overall dimensions thereof, and then releasing it in the body seat (14).