CA1053719A - Combined mold element and sealing ring - Google Patents
Combined mold element and sealing ringInfo
- Publication number
- CA1053719A CA1053719A CA280,619A CA280619A CA1053719A CA 1053719 A CA1053719 A CA 1053719A CA 280619 A CA280619 A CA 280619A CA 1053719 A CA1053719 A CA 1053719A
- Authority
- CA
- Canada
- Prior art keywords
- sealing ring
- mold element
- sealing
- combined mold
- set forth
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000007789 sealing Methods 0.000 title claims abstract description 115
- 230000003014 reinforcing effect Effects 0.000 claims abstract description 27
- 230000002093 peripheral effect Effects 0.000 claims description 24
- 239000000463 material Substances 0.000 claims description 7
- 230000007704 transition Effects 0.000 claims description 3
- 238000004519 manufacturing process Methods 0.000 abstract description 9
- 238000004873 anchoring Methods 0.000 abstract description 4
- 238000000465 moulding Methods 0.000 abstract description 4
- 229920001169 thermoplastic Polymers 0.000 abstract description 3
- 239000004416 thermosoftening plastic Substances 0.000 abstract description 3
- 230000006835 compression Effects 0.000 description 7
- 238000007906 compression Methods 0.000 description 7
- 230000000694 effects Effects 0.000 description 6
- 230000002787 reinforcement Effects 0.000 description 4
- 241000251468 Actinopterygii Species 0.000 description 3
- 230000001921 mouthing effect Effects 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 230000014509 gene expression Effects 0.000 description 2
- 238000005304 joining Methods 0.000 description 2
- 238000011068 loading method Methods 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- TVEXGJYMHHTVKP-UHFFFAOYSA-N 6-oxabicyclo[3.2.1]oct-3-en-7-one Chemical group C1C2C(=O)OC1C=CC2 TVEXGJYMHHTVKP-UHFFFAOYSA-N 0.000 description 1
- 101100322245 Caenorhabditis elegans des-2 gene Proteins 0.000 description 1
- 230000001427 coherent effect Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 229920000136 polysorbate Polymers 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 239000012815 thermoplastic material Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C57/00—Shaping of tube ends, e.g. flanging, belling or closing; Apparatus therefor, e.g. collapsible mandrels
- B29C57/02—Belling or enlarging, e.g. combined with forming a groove
- B29C57/025—Belling or enlarging, e.g. combined with forming a groove combined with the introduction of a sealing ring, e.g. using the sealing element as forming element
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L47/00—Connecting arrangements or other fittings specially adapted to be made of plastics or to be used with pipes made of plastics
- F16L47/06—Connecting arrangements or other fittings specially adapted to be made of plastics or to be used with pipes made of plastics with sleeve or socket formed by or in the pipe end
- F16L47/08—Connecting arrangements or other fittings specially adapted to be made of plastics or to be used with pipes made of plastics with sleeve or socket formed by or in the pipe end with sealing rings arranged between the outer surface of one pipe end and the inner surface of the sleeve or socket, the sealing rings being placed previously in the sleeve or socket
- F16L47/10—Connecting arrangements or other fittings specially adapted to be made of plastics or to be used with pipes made of plastics with sleeve or socket formed by or in the pipe end with sealing rings arranged between the outer surface of one pipe end and the inner surface of the sleeve or socket, the sealing rings being placed previously in the sleeve or socket the sealing rings being maintained in place by additional means
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Shaping Of Tube Ends By Bending Or Straightening (AREA)
- Joints With Pressure Members (AREA)
- Gasket Seals (AREA)
- Shaping Metal By Deep-Drawing, Or The Like (AREA)
- Seal Device For Vehicle (AREA)
Abstract
A COMBINED MOLD ELEMENT AND SEALING RING
Abstract of the Disclosure The combined mold element and sealing ring is formed of an elastically yieldable body and a rigid reinforcing non-elastic member within the body on a side spaced away from the leading edge of the body. The unit may be generally drop-shape, or otherwise, and is formed with minimal bulk.
Positioning of the reinforcing member close to the outer radial portion of the elastic body reduces the manufac-turing costs of the combined element as the bulk of the element may be reduced and the positioning of the rigid member in the rubber molds is facilitated. The reduced bulk also facilitates the molding of a thermoplastic pipe end over the unit to form a socket by reduced stretching of the pipe.
The positioning of the rigid ring member also facilitates the anchoring eff ct of the combined element when used in a pipeline with internal pressure.
Abstract of the Disclosure The combined mold element and sealing ring is formed of an elastically yieldable body and a rigid reinforcing non-elastic member within the body on a side spaced away from the leading edge of the body. The unit may be generally drop-shape, or otherwise, and is formed with minimal bulk.
Positioning of the reinforcing member close to the outer radial portion of the elastic body reduces the manufac-turing costs of the combined element as the bulk of the element may be reduced and the positioning of the rigid member in the rubber molds is facilitated. The reduced bulk also facilitates the molding of a thermoplastic pipe end over the unit to form a socket by reduced stretching of the pipe.
The positioning of the rigid ring member also facilitates the anchoring eff ct of the combined element when used in a pipeline with internal pressure.
Description
`~" 1053`~19 This invention relates to a combined mold element and sealing ring. More particularly, this invention relates to a reinforced combined forming element and sealing ring for seal-ing pipe socket joints which may be exposed to high internal pressures as well as low pressure and vacuum.
The combined mold element and sealing ring has two distinct and different purposes, i.e. one as a mold element and one as a sealing ring. In this respect, the expressions "mold element" and "sealing ring" are used hereinafter to clarify distinct effects in each case. It will, however, be understood that both expressions refer to one and the same construction unit. For example, the sealing ring is used for sealing off a joint between a socket end and an insert end of two cooperating pipes which are formed from thermoplastic material. The mold or forming element is used as a portion of a body of a mold for both fabricating the socket end of one pipe and simultaneously inserting the ring in an internal groove or race-way in the socket end produced thereby.
Usually, the mold element is mounted on a drift for this purpose and is made of an elastically yieldable material such as rubber.
Generally, during asse~ling and joining of the spigot and socket ends, the sealing ring will be compressed in a manner corresponding substantially to the compression which the mold element is exposed to during the disassembling of the mold element from the drift. Usually, the drift has an external form corresponding essentially to the internal form of the pipe socket to be produced. The internal form of the pipe to be produced is, thus, substantially cylindrical with a sealing
The combined mold element and sealing ring has two distinct and different purposes, i.e. one as a mold element and one as a sealing ring. In this respect, the expressions "mold element" and "sealing ring" are used hereinafter to clarify distinct effects in each case. It will, however, be understood that both expressions refer to one and the same construction unit. For example, the sealing ring is used for sealing off a joint between a socket end and an insert end of two cooperating pipes which are formed from thermoplastic material. The mold or forming element is used as a portion of a body of a mold for both fabricating the socket end of one pipe and simultaneously inserting the ring in an internal groove or race-way in the socket end produced thereby.
Usually, the mold element is mounted on a drift for this purpose and is made of an elastically yieldable material such as rubber.
Generally, during asse~ling and joining of the spigot and socket ends, the sealing ring will be compressed in a manner corresponding substantially to the compression which the mold element is exposed to during the disassembling of the mold element from the drift. Usually, the drift has an external form corresponding essentially to the internal form of the pipe socket to be produced. The internal form of the pipe to be produced is, thus, substantially cylindrical with a sealing
- 2 -1 ring extending somewhat radially inwards so as to provide a 2 seal against a spigot end of a pipe which is to be inserted in
3 the socket. However, when the spigot is inserted into the
4 socket, it is of importance that the sealing ring is not dis-located or pushed out of the groove even if the spigot is not 6 properly chamfered.
7 Further, it is known that the expansion of the 8 grooved portion of the socket end, wherein the sealing ring is 9 supported, stretches this portion into a relatively thin and, thus, weakened pipe wall. During storage and transportation, 11 therefore, the pipes usually rest on the most stretched out 12 parts of the pipe ends, Unintentional earth loading, traffic 13 load, stones and the like will also be more easily transferred 14 to these most outwardly projecting parts of the socket end.
Hence, a support of these parts is advantageous to prevent un-16 intended deformations, and even breakages, as a consequence 17 of blows as may readily occur during transportation and handling 18 of the pipes as well as during installation of the pipelines.
19 In connection with heat strains in the pipe, such as can occur on storage ~slacking of the pipes) in hot summer weather, and 21 by use close to sources of heat (steam pipes in the same 22 ditch) etc., there is an advantage in bracing the annular 23 groove by use of a stiffened sealing ring to avoid deformation 24 and the like which may lead to loss of compression and leakages.
Accordingly, it is an object of the invention to 26 provide a combined mold element and sealing ring which will 27 not be pushed out of a groove of a pipe socket during insertion 28 of a spigot which is not properly chamfered.
29 It is another object of the invention to reduce the stretching of the material in a socket end of a pipe during 31 fabrication.
32 It is another object of the nvention to strengthen 1 the socket end of a pipe and to reduce the risk of unintended 2 deformations, 3 It is another object of the invention to provide a 4 reinforced combined forming element and sealing ring for sealing pipe socket joints whlch may be exposed to high internal pres-6 sures as well as low pressure and vacuum.
7 It is another object of the invention to produce 8 a sealing ring with a minimal cross-section and, thus, a 9 minimum volume in order to reduce the manufacturing costs of the sealing ring as much as possible.
11 It is another object of the invention to provide a 12 combined forming element and sealing ring with very close 13 tolerances to ensure a safe and relatively constant compression 14 in pipe joints while simultaneously lowering the manufacturing cost of the ring.
16 It is another object of the invention to produce a 17 combined forming element and sealing ring where the molding of 18 the element with the reinforcing member is facilitated by plac-19 ing the reinforcing ring member in ~rQferred locations in the molds to avoid dislocatiors of the reinforcing member during 21 the molding of the combined element and by diameter variations 22 due to tolerances of the reinforcing ring diameter.
23 It is another object of the invention to have a com-24 bined element where the outer contour$ of the element corres-pond with the forming properties of a hot thermoplastic pipe 26 end.
27 - Briefly, the invention provides a combined mold 28 element and sealing ring comprising an annular body of e~as-29 tically yieldable material and a rigid reinforcing non-elastic member disposed in the body. The annular body has opposite 31 side portions, an inner peripheral surface defining at least 32 one radially inwardly protruding sealing portion located between 1053719 ~ I
1 the opposite side portions, and an outer peripheral surface 2 having an outer radially directed surface portion located be-3 tween the side portions. The rigid reinforcing non-elastic 4 member is located in an area defined between the opposite side portions and is spaced radially outside the protruding 6 sealing portion.
7 The combined mold element and sealing ring can be 8 used to form a groove with a locked in sealing ring during 9 the socketing operation of a hot end of a pipe. By locating the rigid reinforcing element of the combined element in the 11 outer radial portion, the anchoring effect of the element 12 within the socket of the pipe is facilitated.
13 The hot pipe can be formed with rather steep angles 14 and small curves in the most stretched portions of the groove.
Also, by allowing the hot pipe end to be sucked down with a 16 steep angle in front of the outer radial portion of the 17 combined element, the anchoring effect is improved. A steep 18 angle is achieved by making a step in the outer radial portion 19 of the mold for manufacturing the combined elements and, at the same time, the positioning of the rigid member may be 21 facilitated during the molding operation by positioning the 22 ring member at the step in the mold. In order to anchor the 23 sealing ring against being pressed out in the annular gap 2~ between spigot and socket by internal pressure in the pipe-line, it is advantageous to position the rigid ring member 26 close to the rear of the combined element. In order to anchor 27 the sealing ring against being dislocated or pushed out of 28 the groove by the spigot during assembling of the pipes, it 29 is, however, advantageous to place the rigid ring member close to the front! that is, closed to a leading edge.
31 In one embodiment, the inner peripheral surface of 32 he annular body has a conically shaped portion extending from 1 the sealing portion to define a leading edge with the outer 2 surface portion. In another embodiment, the inner peripheral 3 surface has a second portion spaced from the sealing portion 4 and defining a leading edge with the outer peripheral surface.
The reinforcing member may either be completely or 6 partially embedded within the annular body and may be of any 7 suitable cross-sectional shape to obtain the specific advan-8 tages desired in each case. For example, the reinforcing 9 member may be a ring of annular or curvilinear cross-section or may be made of a pair of annular rings with a plurality of 11 webs connecting the rings together.
12 The inner peripheral sealing portion of the annular 13 body can be rounded or flat or can be formed as a sealing lip.
14 Similarly, the annular body may have a rounded or flattened outer radial portion.
16 The combined mold element and sealing ring can be 17 positioned in a pipe joint comprised of two pipes. For ex-18 ample, where the pipes are made of PVC, the mold element is 19 mounted on a drift of a mold apparatus and one pipe end is heated and forced over the mold element. This causes the pipe 2221 end to form a socket with an internal annular groove or race-23 way about the mold element as described in my copending application. Thereafter, the mold element and pipe socket are 24 removed from the mold apparatus, and the end of another pipe is inserted as a spigot into the socket end.
26 The sealing elements can be manufactured economically 27 and with very close tolerances. This is achieved by making the 28 sealing element with very little elastically yieldable material, 29 i.e. very little rubber bulk and by anchoring the rubber bulk to a rigid ring member in a portion radially opposite the 31 sealing portion. In the case of ordinary rubber sealing rings 32 ere are limitations in how small the rings can be made 1~537~9 because rings with little rubber bulk are easily dislocated or pressed out of the race-way by joining of a pipe-line or pressed out into the annular gap between a spigot end and socket end by internal pressure in a pipe line.
It is a general tendency that sealing rings and especially unreinforced sealing rings may be s~ueezed out of the gap spacing the spigot end from the socket end when . exposed to high internal pressure. This may also be the case with sealing rings reinforced with rigid ring members of minor thickness. However, in the present case, this problem can be solved by using a reinforcing member provided with a minimum cross-sectional dimension, i.e. a cross-section diameter, greater than the annular space separating the-outer surface of the spigot end from the inner surface of the socket end.
Other limitations of ordinary sealing rings reside in the need for relatively large productiGn tolerances which demand relatively much rubber volume to assure the sealing effect between socket and spigot. By locating the rigid ring member close to or in the same radial plane as the sealing area of the sealing ring, it is possible to produce sealing rings with very close diameter tolerances in the sealing area. This allows the rubber bulk to be reduced without influencing the sealing property of the sealing ring and at the same time eliminates the possibility of dislocating or pushing out the rubber ring with the spigot end during assembling or by internal pressure in the pipe-line.
Further, because the bulk of the sealing ring can be reduced, it is also possible to reduce the height of the race-way. This reduces the stretching and the thinning of the race-way and thus gives great advantages to the strength of the pipeline.
-In accordance with an aspect of the present inventionthere is provided a combined mold element and sealing ring comprising an annular body of elastically yieldable material, said body having opposite side portions, an inner peripheral surface defining at least one radially inwardly protruding sealing portion located between said opposite side portions, and an outer peripheral surface having an outer radially directed surface portion located between said side portions; and a rigid reinforcing`
non-elastic member disposed in said body and located in an area defined between said opposite side portions and spaced radially outside said protruding sealing portion.
These and other objects and advantages of the inven-- 7a -1 tion will become more apparent from the following detailed des-2 cription and appended claims taken in conjunction with the ac-3 companying drawings, in which:
4 Fig. l illustrates a part cross-sectional view of a combined mold element and sealing ring in accordance with the invention;
7 Fig. 2 illustrates a part cross-sectional view of a 8 modified combined mold element and sealing ring having a 9 second inner peripheral portion defining a leading edge with an outer surface portion in accordance with the invention;
11 Fig. 3 illustrates a part cross-sectional view of a 12 further modified combined mold element and sealing ring having 13 a rounded leading edge in accordance with the invention;
14 Fig. 4 illustrates a part cross-sectional view of a further modified combined mold element and sealing ring having 16 a reinforcing member of curvilinear cross-section in accord-17 ance with the invention;
18 Fig. 5 illustrates a part cross-sectional view of a 19 further modified combined mold element and sealing ring having 2l a reinforcing member cpmposed of a pair of rings of circular 22 cross-section;
Fis. 6 illustrates a part cross-sectional view of a 24 modified mold element and sealing ring having a sealing lip on the inner periphery in accordance with the invention;
Fig. 7 illustrates a part cross-sectional view of a 26 combined mold element and sealing ring similar to that of 27 Fig. 2 on a drift of a mold apparatus;
28 Fig, 8 illustrates a part cross-sectional view of a 29 combined mold element and sealing ring similar to that of Fig. 2 on a drift of a mold apparatus with a pipe socket formed 31 thereover;
32 Fig. 9 illustrates a part cross-seciiona1 view of a 1053'719 1 combined mld element and sealing ring similar to that of 2 Fig. 2 in a pipe socket;
3 Fig. 10 illustrates a part cross-sectional view of a 4 pipe joint in a pipe line with internal pressure imposed on the combined mold element and sealing ring similar to that of 6 Fig. 2; and 7 Fig. 11 illustrates a part sectional view of one 8 embodiment of a die for manufacturing of a combined mold 9 element and sealing ring in accordance with the invention.
Referring to Fig. 1, the combined mold element and 12 sealing ring 20 is formed of an annular body 21 of elastically yieldable material, such as rubber, and a rigid 13 reinforcing non-elastic member 22. The annular body 21 is of 14 a cross-section which is mainly dropshape and has an inner peripheral surface defining a rounded radially inwardly pro-67 truding sealing portion 23 and a plain, conically shaped portion 24 extending from the rounded portion 23, an 18 obliquely extending (i.e. conical) outer surface portion 25 on 19 one side which forms a leading edge 26 with the conical portion 24, an outer peripheral surface having a rounded outer 21 radially directed surface portion 27 adjacent the surface 22 portion 25 and a rounded nose portion 28 on the opposite side.
23 As shown, the rigid member 22 which is in the form of an 24 annular ring with a circular cross-section is embedded close to the nose portion 28, i.e. at a point where the nose portion 26 28 and the outer radial portion 27 merge. As shown, the surface 27 of the ring member 22 is close to a transition area between 28 the nose portion 28 and outer peripheral portion 27.
29 As shown in Fig. 1, the radial plane A through the mid-point of the sealing portion or rounded portion 23 is 31 located between the radial plane B of the member 22 and a 32 eading side portion de~ined ~etween the conical inner sur~ace ~ ;
1 portion 24 and the conical outer surface portion 25. The radial 2 plane is defined as a plane with a 90 angle with the center 3 line of a pipe.
4 Re~erring to Fig. 2, wherein like reference charac-~ ters indicate like parts as above, the cornbined mold and seal 6 rinq 30 has a plain or slightly conical inner portion 41 7 spaced from the sealing portion 23. This portion 41 8 tapers radially outwardly towards the conical portion 25 to 9 form the leading edge 26. In addition, a recessed portion 42 of concave shape is formed between the sealing portion or rounded 11 portion 23 and the portion 41. As shown in Fig. 2, 12 the radial plane B of the member 22 is located between the 13 radial plane A through the midpoint of the sealing portion or 14 rounded portion 23 and a radial plane G through the leading surface portion 25. The position of the ring member 22 is 16 chosen at a level radially outside the leading edge 26 of the mold element 4~ in order, thereby~ to ensure an intentional 18 pressing down of the leading edge 26 during the pushing-on 19 of a hot pipe end over the unit~4~.
Referring to Fig. 7, a mold apparatus 31 for 21 forming a socket in an end of a thermoplastic pipe (not shown) 22 ~o receive a combined mo~ld element and sealing ring 40(similar to 23 Fig. 2) includes a drift 32 with a recess/and a support ring 24 34. The recess 33 in the drift 32 accomodates the annular body 21 of the unit 40, and the support ring 34 is shaped to mate 26 with the nose portion 28 and to force the nose portion up-27 wards to avoid any tilting of the mold element that could 28 cause "fish mouthing" with the pipe end and mold element 29 during pushing on the hot pipe end (Fig. 8~. The manner of forming a pipe end over the combined mold and sealing ring 31 40 in the mold apparatus 31 is similar to that as described 32 in my copending application and need not be further described.
~j 1053719 1 As shown in Fig. 8, after forming, a pipe 35 is bulqed 2 radially outwardly over the unit 40 and has a groove or 3 race-way 36 in which the unit 40 is received. As shown, the 4 inner diameter d (Fig. 9) of the unit 40 is less than the inner diameter D of the socket end of the pipe 35. Also, 6 as shown, the pipe 35 and unit 40 mate against each other 7 almost continuously from the nose portion 28 to the leading 8 edge 26 (depending somewhat on pipe thickness).
9 As shown in Fig. 10, after positioning of a second pipe 37 having a chamfered spigot end within the pipe 35, 11 the unit 40 forms a tight seal between the pipes 35, 37. As 12 shown, the inner pipe 37 has an outer diameter greater than 13 the inner diameter of the unit 40. Thus, the body 21 of the 14 unit 40 is compressed and yieldably deformed. However, the ring member 22 is not deformed and remains in original shape.
16 This serves to positively retain the unit 40 in place 17 againSt pressures imposed on the unit 40 within the gaps 18 between the pipes 35, 37.
19 As visualized in Fig. lO, the sealing ring is pressed into the annular gap between the socket 35 and spigot 21 37 by internal pressure in the pipe line but is anchored by 22 the reinforcement of the ring 22, e.g. a steel ring, molded 23 into the rubber bulk of the annular body 21.
24 Fig. 7 further illustrates how the reinforcement ring member 22 together with the supporting ring 3g securely 26 holds the mold element on the drift 32 by compressing the 27 rubber bulk against the drift 32. The dotted line shows the 28 unloaded position of the nose portion. The reinforcing ring 29 member 22 allows the rubber bulk to be pressed against the drift surface without allowing the outer portion of the mold 31 element to be stretched or dislocated, and the supporting ring 3~ 34 oids any tilting of the mold element. This allows a hot 1053719 l l 1 pipe end to be pushed over the drift 32 and the mold element 40 2 while retaining the correct o~ter contours of the raceway when 3 the pipe has been shrunk, sucked and cooled down according to 4 U.S. Patent 3,776,682, as shown in Fig. 8. In Fig. 8, the dotted lines show the position of the nose portion before re-6 traction of the supporting ring 34.
7 The drift 32 according to Fig. 7 has longitudinal 8 slots 38 to allow air to be sucked out on both sides of the mold 9 element via vacuum bores (not shown). In order to avoid "fish-mouthing" and to assure a good positioning of the mold 11 element on the drift 32, a small recess 33 for the mold element 12 is provided above the longitudinal slots 38. The section C, as 13 marked with crossing lines, shows the compression of the mold 14 element against the drift 32.
Referring to Fig. 2, by positioning the rin~ member 16 22 over the sealing portion 23 or in a direction towards the 17 leading edge 26 any tilting of the mold element is avoided 18 during movement of the mold element axially on a drift, and no 19 "fish mouthing" occurs during the following pushing on the 21 hot pipe end. In case the ring member 22 is positioned more to 22 the left, as viewed, the tilting and "fish mouthing" can be 23 avoided by using a support ring 34, as shown in Fig. 7, to lift up the nose section and force the leading edge 26 down on 24 to the drift.
Referring to Fig, 3~ wherein like reference characters 26 indicate like parts as above, the combined mold and sealing 27 ring 50 may be formed with a different cross-section from a 28 drop-shape. As shown, the unit 50 may have a rounded leading 29 portion 51 on one side adjacent the conical surface portion 25.
This leading portion 51 merges with the inner peripheral portion 31 23 to define a concave recess therebetween. The cross-section 32 o he unit 50 is suitable for a mold apparatus as described in 1053719 l l 1 U.S. Patent 3,793,427.
2 Referring to Fig. 4, the combined mold element and 3 sealing ring 60 may also be formed with a ring member 61 4 which is of curvilinear cross-section. As shown, the ring mem-ber 61 is in the form of a metal hoop ring member of especially 6 - rigid form, which is particularly favorable for the reception 7 of external as well as internal radial loadings. The ring 8 member 61 is disposed with an exposed surface between the nose 9 portion 28 and outer peripheral portion 27 of the annular body 21. In this way, the ring member 61 is especially suitable 11 for forming an internal support for the socket end in the 12 weakened stretched race-way. The ring member 61 will, in 13 addition, form an effective support for the sealing ring and 14 prevent the unit 60 from being pressed into the annular gap between spigot end and socket end by internal excess pressure 16 in ~ne pipe line, as illustrated in Fig. 10.
17 It is apparent that the ring member 22 can be de- _ 18 signed in various other ways and can be positioned in various 19 ways other than those which are shown in order to be adapted according to existing support means of the mold apparatus or 21 in order to satisfy other demands of the sealing ring, 22 If desired, as shown in Fig. 5, two or more ring members 62 can 23 be combined in one and the same construction and, moreover, 24 such ring members 62 can be connected to each other into a coherent rigid member, for example with separate connectinq 26 webs 63 between the rings 62.
27 Further, as shown in Fig. 6, the combined mold 28 element and sealing ring 70 may be formed with an internal 29 peripheral portion 71 which defines a sealing lip (shown in an unloaded state). In this case, a recess 72 is formed between 31 the sealing lip 71 and the plain portion 41. Thus, instead of 32 forming a compression seal when in place, a lip seal is formed, 1 ~
1~53719 1 As shown in Fig. 8 and lO, pressure areas E are 2 initially formed in the sealing portion 23 of the unit 40 when 3 moving the unit 40 into position on the drift as illustrated 4 in Fig. 7 and, thereafter, are formed in the outer periphery after the hot pipe end is moved over the unit 40, as illu-6 strated in Fig. 8, and hence cooled and shrunk radially 7 towards the unit 40 and the drift 32. In the æ manufacturing 8 stepSof the pipe socket end, the rigid ring member 22 reinforces 9 the unit 40 in order to control the pressure effects involved in the internal as well as in the external parts of the unit 11 40. Referring to Fig. 9, after the socket end and the 12 associated unit 40 are removed from the drift, the pressured 13 areas as illustrated in Fig. 8 are substantially released.
14 The remaining compression as illustrated in areas F assures a good bite and prevents dirt and the like from penetrating into 16 the sealing areas. When moving a spigot end into a socket end, 17 the unit 40 will be compressed similarly to the compression 18 illustrated in the manufacturing step of Fig. 8 and similar 19 pressure areas will arise in the socket end and in the spigot end. Referring to Fig. lO, when a pressure medium is transported 21 through a pressure pipe line incorporating the illustrated 22 pipe joint, the medium is allowed to penetrate into a gap 23 formed between the sealing unit 40 and the socket end. In this 24 latter case, the pressure areas E of the unit 40 are located as indicated in Fig. lO. The effect of the pressure areas 26 provided by the resilient body 21 of the sealing unit 40 in 2~ cooperation with the reinforcing ring member 22 of the sealing 28 unit provides an effective seal against leakage between the 29 socket end and the spigot end of the illustrated pipe line joint.
31 Referring to Fig. ll, a sealing unit 40 can be formed 32 n a mold in a known manner. ~or examplel the unit 40 can be 10~3~19 formed in a cavity 80 formed between three separate, 2 cooperating die parts 81, 82, 83. The manufacturing of the 3 sealing unit 40 is made by locating a prefabricated steel ring 4 member 22 in the cavity 80 on a set of pins 84 which might be withdrawable. Only one pin is illustrated in the drawing in 6 dotted lines. These pins 84 protrude from the internal side of 7 one part 8~ of the die in mutually spaced relation along 8 the internal side of the die part. ~ sy means of such pins, 9 each ring is supported in a rela~i~ely accurate manner in the die to secure accurate reinforcing effects in the unit 40 11 produced therein. Before the produced unit is removed from 12 the die, the pins 84 are withdrawn from the unit and the 13 associated die part. The elasticity of the rubber allows 14 release of the unit 40 from the mold and the pins, even if the pins are permanently connected to the mold surface and are not 16 movable relative thereto.
17 The mold portions are wlthdrawn in directions x, y 18 relative to the unit in order to release the unit 40.
19 All the accompanying Figures of the combined sealing and f~orming element cross-section show the reinforcement placed 21 near the rubber bulk surface. However, the reinforcement can ~5 ~e loc ed ~n spaced relation from the outer surface. ¦
227 ' .
7 Further, it is known that the expansion of the 8 grooved portion of the socket end, wherein the sealing ring is 9 supported, stretches this portion into a relatively thin and, thus, weakened pipe wall. During storage and transportation, 11 therefore, the pipes usually rest on the most stretched out 12 parts of the pipe ends, Unintentional earth loading, traffic 13 load, stones and the like will also be more easily transferred 14 to these most outwardly projecting parts of the socket end.
Hence, a support of these parts is advantageous to prevent un-16 intended deformations, and even breakages, as a consequence 17 of blows as may readily occur during transportation and handling 18 of the pipes as well as during installation of the pipelines.
19 In connection with heat strains in the pipe, such as can occur on storage ~slacking of the pipes) in hot summer weather, and 21 by use close to sources of heat (steam pipes in the same 22 ditch) etc., there is an advantage in bracing the annular 23 groove by use of a stiffened sealing ring to avoid deformation 24 and the like which may lead to loss of compression and leakages.
Accordingly, it is an object of the invention to 26 provide a combined mold element and sealing ring which will 27 not be pushed out of a groove of a pipe socket during insertion 28 of a spigot which is not properly chamfered.
29 It is another object of the invention to reduce the stretching of the material in a socket end of a pipe during 31 fabrication.
32 It is another object of the nvention to strengthen 1 the socket end of a pipe and to reduce the risk of unintended 2 deformations, 3 It is another object of the invention to provide a 4 reinforced combined forming element and sealing ring for sealing pipe socket joints whlch may be exposed to high internal pres-6 sures as well as low pressure and vacuum.
7 It is another object of the invention to produce 8 a sealing ring with a minimal cross-section and, thus, a 9 minimum volume in order to reduce the manufacturing costs of the sealing ring as much as possible.
11 It is another object of the invention to provide a 12 combined forming element and sealing ring with very close 13 tolerances to ensure a safe and relatively constant compression 14 in pipe joints while simultaneously lowering the manufacturing cost of the ring.
16 It is another object of the invention to produce a 17 combined forming element and sealing ring where the molding of 18 the element with the reinforcing member is facilitated by plac-19 ing the reinforcing ring member in ~rQferred locations in the molds to avoid dislocatiors of the reinforcing member during 21 the molding of the combined element and by diameter variations 22 due to tolerances of the reinforcing ring diameter.
23 It is another object of the invention to have a com-24 bined element where the outer contour$ of the element corres-pond with the forming properties of a hot thermoplastic pipe 26 end.
27 - Briefly, the invention provides a combined mold 28 element and sealing ring comprising an annular body of e~as-29 tically yieldable material and a rigid reinforcing non-elastic member disposed in the body. The annular body has opposite 31 side portions, an inner peripheral surface defining at least 32 one radially inwardly protruding sealing portion located between 1053719 ~ I
1 the opposite side portions, and an outer peripheral surface 2 having an outer radially directed surface portion located be-3 tween the side portions. The rigid reinforcing non-elastic 4 member is located in an area defined between the opposite side portions and is spaced radially outside the protruding 6 sealing portion.
7 The combined mold element and sealing ring can be 8 used to form a groove with a locked in sealing ring during 9 the socketing operation of a hot end of a pipe. By locating the rigid reinforcing element of the combined element in the 11 outer radial portion, the anchoring effect of the element 12 within the socket of the pipe is facilitated.
13 The hot pipe can be formed with rather steep angles 14 and small curves in the most stretched portions of the groove.
Also, by allowing the hot pipe end to be sucked down with a 16 steep angle in front of the outer radial portion of the 17 combined element, the anchoring effect is improved. A steep 18 angle is achieved by making a step in the outer radial portion 19 of the mold for manufacturing the combined elements and, at the same time, the positioning of the rigid member may be 21 facilitated during the molding operation by positioning the 22 ring member at the step in the mold. In order to anchor the 23 sealing ring against being pressed out in the annular gap 2~ between spigot and socket by internal pressure in the pipe-line, it is advantageous to position the rigid ring member 26 close to the rear of the combined element. In order to anchor 27 the sealing ring against being dislocated or pushed out of 28 the groove by the spigot during assembling of the pipes, it 29 is, however, advantageous to place the rigid ring member close to the front! that is, closed to a leading edge.
31 In one embodiment, the inner peripheral surface of 32 he annular body has a conically shaped portion extending from 1 the sealing portion to define a leading edge with the outer 2 surface portion. In another embodiment, the inner peripheral 3 surface has a second portion spaced from the sealing portion 4 and defining a leading edge with the outer peripheral surface.
The reinforcing member may either be completely or 6 partially embedded within the annular body and may be of any 7 suitable cross-sectional shape to obtain the specific advan-8 tages desired in each case. For example, the reinforcing 9 member may be a ring of annular or curvilinear cross-section or may be made of a pair of annular rings with a plurality of 11 webs connecting the rings together.
12 The inner peripheral sealing portion of the annular 13 body can be rounded or flat or can be formed as a sealing lip.
14 Similarly, the annular body may have a rounded or flattened outer radial portion.
16 The combined mold element and sealing ring can be 17 positioned in a pipe joint comprised of two pipes. For ex-18 ample, where the pipes are made of PVC, the mold element is 19 mounted on a drift of a mold apparatus and one pipe end is heated and forced over the mold element. This causes the pipe 2221 end to form a socket with an internal annular groove or race-23 way about the mold element as described in my copending application. Thereafter, the mold element and pipe socket are 24 removed from the mold apparatus, and the end of another pipe is inserted as a spigot into the socket end.
26 The sealing elements can be manufactured economically 27 and with very close tolerances. This is achieved by making the 28 sealing element with very little elastically yieldable material, 29 i.e. very little rubber bulk and by anchoring the rubber bulk to a rigid ring member in a portion radially opposite the 31 sealing portion. In the case of ordinary rubber sealing rings 32 ere are limitations in how small the rings can be made 1~537~9 because rings with little rubber bulk are easily dislocated or pressed out of the race-way by joining of a pipe-line or pressed out into the annular gap between a spigot end and socket end by internal pressure in a pipe line.
It is a general tendency that sealing rings and especially unreinforced sealing rings may be s~ueezed out of the gap spacing the spigot end from the socket end when . exposed to high internal pressure. This may also be the case with sealing rings reinforced with rigid ring members of minor thickness. However, in the present case, this problem can be solved by using a reinforcing member provided with a minimum cross-sectional dimension, i.e. a cross-section diameter, greater than the annular space separating the-outer surface of the spigot end from the inner surface of the socket end.
Other limitations of ordinary sealing rings reside in the need for relatively large productiGn tolerances which demand relatively much rubber volume to assure the sealing effect between socket and spigot. By locating the rigid ring member close to or in the same radial plane as the sealing area of the sealing ring, it is possible to produce sealing rings with very close diameter tolerances in the sealing area. This allows the rubber bulk to be reduced without influencing the sealing property of the sealing ring and at the same time eliminates the possibility of dislocating or pushing out the rubber ring with the spigot end during assembling or by internal pressure in the pipe-line.
Further, because the bulk of the sealing ring can be reduced, it is also possible to reduce the height of the race-way. This reduces the stretching and the thinning of the race-way and thus gives great advantages to the strength of the pipeline.
-In accordance with an aspect of the present inventionthere is provided a combined mold element and sealing ring comprising an annular body of elastically yieldable material, said body having opposite side portions, an inner peripheral surface defining at least one radially inwardly protruding sealing portion located between said opposite side portions, and an outer peripheral surface having an outer radially directed surface portion located between said side portions; and a rigid reinforcing`
non-elastic member disposed in said body and located in an area defined between said opposite side portions and spaced radially outside said protruding sealing portion.
These and other objects and advantages of the inven-- 7a -1 tion will become more apparent from the following detailed des-2 cription and appended claims taken in conjunction with the ac-3 companying drawings, in which:
4 Fig. l illustrates a part cross-sectional view of a combined mold element and sealing ring in accordance with the invention;
7 Fig. 2 illustrates a part cross-sectional view of a 8 modified combined mold element and sealing ring having a 9 second inner peripheral portion defining a leading edge with an outer surface portion in accordance with the invention;
11 Fig. 3 illustrates a part cross-sectional view of a 12 further modified combined mold element and sealing ring having 13 a rounded leading edge in accordance with the invention;
14 Fig. 4 illustrates a part cross-sectional view of a further modified combined mold element and sealing ring having 16 a reinforcing member of curvilinear cross-section in accord-17 ance with the invention;
18 Fig. 5 illustrates a part cross-sectional view of a 19 further modified combined mold element and sealing ring having 2l a reinforcing member cpmposed of a pair of rings of circular 22 cross-section;
Fis. 6 illustrates a part cross-sectional view of a 24 modified mold element and sealing ring having a sealing lip on the inner periphery in accordance with the invention;
Fig. 7 illustrates a part cross-sectional view of a 26 combined mold element and sealing ring similar to that of 27 Fig. 2 on a drift of a mold apparatus;
28 Fig, 8 illustrates a part cross-sectional view of a 29 combined mold element and sealing ring similar to that of Fig. 2 on a drift of a mold apparatus with a pipe socket formed 31 thereover;
32 Fig. 9 illustrates a part cross-seciiona1 view of a 1053'719 1 combined mld element and sealing ring similar to that of 2 Fig. 2 in a pipe socket;
3 Fig. 10 illustrates a part cross-sectional view of a 4 pipe joint in a pipe line with internal pressure imposed on the combined mold element and sealing ring similar to that of 6 Fig. 2; and 7 Fig. 11 illustrates a part sectional view of one 8 embodiment of a die for manufacturing of a combined mold 9 element and sealing ring in accordance with the invention.
Referring to Fig. 1, the combined mold element and 12 sealing ring 20 is formed of an annular body 21 of elastically yieldable material, such as rubber, and a rigid 13 reinforcing non-elastic member 22. The annular body 21 is of 14 a cross-section which is mainly dropshape and has an inner peripheral surface defining a rounded radially inwardly pro-67 truding sealing portion 23 and a plain, conically shaped portion 24 extending from the rounded portion 23, an 18 obliquely extending (i.e. conical) outer surface portion 25 on 19 one side which forms a leading edge 26 with the conical portion 24, an outer peripheral surface having a rounded outer 21 radially directed surface portion 27 adjacent the surface 22 portion 25 and a rounded nose portion 28 on the opposite side.
23 As shown, the rigid member 22 which is in the form of an 24 annular ring with a circular cross-section is embedded close to the nose portion 28, i.e. at a point where the nose portion 26 28 and the outer radial portion 27 merge. As shown, the surface 27 of the ring member 22 is close to a transition area between 28 the nose portion 28 and outer peripheral portion 27.
29 As shown in Fig. 1, the radial plane A through the mid-point of the sealing portion or rounded portion 23 is 31 located between the radial plane B of the member 22 and a 32 eading side portion de~ined ~etween the conical inner sur~ace ~ ;
1 portion 24 and the conical outer surface portion 25. The radial 2 plane is defined as a plane with a 90 angle with the center 3 line of a pipe.
4 Re~erring to Fig. 2, wherein like reference charac-~ ters indicate like parts as above, the cornbined mold and seal 6 rinq 30 has a plain or slightly conical inner portion 41 7 spaced from the sealing portion 23. This portion 41 8 tapers radially outwardly towards the conical portion 25 to 9 form the leading edge 26. In addition, a recessed portion 42 of concave shape is formed between the sealing portion or rounded 11 portion 23 and the portion 41. As shown in Fig. 2, 12 the radial plane B of the member 22 is located between the 13 radial plane A through the midpoint of the sealing portion or 14 rounded portion 23 and a radial plane G through the leading surface portion 25. The position of the ring member 22 is 16 chosen at a level radially outside the leading edge 26 of the mold element 4~ in order, thereby~ to ensure an intentional 18 pressing down of the leading edge 26 during the pushing-on 19 of a hot pipe end over the unit~4~.
Referring to Fig. 7, a mold apparatus 31 for 21 forming a socket in an end of a thermoplastic pipe (not shown) 22 ~o receive a combined mo~ld element and sealing ring 40(similar to 23 Fig. 2) includes a drift 32 with a recess/and a support ring 24 34. The recess 33 in the drift 32 accomodates the annular body 21 of the unit 40, and the support ring 34 is shaped to mate 26 with the nose portion 28 and to force the nose portion up-27 wards to avoid any tilting of the mold element that could 28 cause "fish mouthing" with the pipe end and mold element 29 during pushing on the hot pipe end (Fig. 8~. The manner of forming a pipe end over the combined mold and sealing ring 31 40 in the mold apparatus 31 is similar to that as described 32 in my copending application and need not be further described.
~j 1053719 1 As shown in Fig. 8, after forming, a pipe 35 is bulqed 2 radially outwardly over the unit 40 and has a groove or 3 race-way 36 in which the unit 40 is received. As shown, the 4 inner diameter d (Fig. 9) of the unit 40 is less than the inner diameter D of the socket end of the pipe 35. Also, 6 as shown, the pipe 35 and unit 40 mate against each other 7 almost continuously from the nose portion 28 to the leading 8 edge 26 (depending somewhat on pipe thickness).
9 As shown in Fig. 10, after positioning of a second pipe 37 having a chamfered spigot end within the pipe 35, 11 the unit 40 forms a tight seal between the pipes 35, 37. As 12 shown, the inner pipe 37 has an outer diameter greater than 13 the inner diameter of the unit 40. Thus, the body 21 of the 14 unit 40 is compressed and yieldably deformed. However, the ring member 22 is not deformed and remains in original shape.
16 This serves to positively retain the unit 40 in place 17 againSt pressures imposed on the unit 40 within the gaps 18 between the pipes 35, 37.
19 As visualized in Fig. lO, the sealing ring is pressed into the annular gap between the socket 35 and spigot 21 37 by internal pressure in the pipe line but is anchored by 22 the reinforcement of the ring 22, e.g. a steel ring, molded 23 into the rubber bulk of the annular body 21.
24 Fig. 7 further illustrates how the reinforcement ring member 22 together with the supporting ring 3g securely 26 holds the mold element on the drift 32 by compressing the 27 rubber bulk against the drift 32. The dotted line shows the 28 unloaded position of the nose portion. The reinforcing ring 29 member 22 allows the rubber bulk to be pressed against the drift surface without allowing the outer portion of the mold 31 element to be stretched or dislocated, and the supporting ring 3~ 34 oids any tilting of the mold element. This allows a hot 1053719 l l 1 pipe end to be pushed over the drift 32 and the mold element 40 2 while retaining the correct o~ter contours of the raceway when 3 the pipe has been shrunk, sucked and cooled down according to 4 U.S. Patent 3,776,682, as shown in Fig. 8. In Fig. 8, the dotted lines show the position of the nose portion before re-6 traction of the supporting ring 34.
7 The drift 32 according to Fig. 7 has longitudinal 8 slots 38 to allow air to be sucked out on both sides of the mold 9 element via vacuum bores (not shown). In order to avoid "fish-mouthing" and to assure a good positioning of the mold 11 element on the drift 32, a small recess 33 for the mold element 12 is provided above the longitudinal slots 38. The section C, as 13 marked with crossing lines, shows the compression of the mold 14 element against the drift 32.
Referring to Fig. 2, by positioning the rin~ member 16 22 over the sealing portion 23 or in a direction towards the 17 leading edge 26 any tilting of the mold element is avoided 18 during movement of the mold element axially on a drift, and no 19 "fish mouthing" occurs during the following pushing on the 21 hot pipe end. In case the ring member 22 is positioned more to 22 the left, as viewed, the tilting and "fish mouthing" can be 23 avoided by using a support ring 34, as shown in Fig. 7, to lift up the nose section and force the leading edge 26 down on 24 to the drift.
Referring to Fig, 3~ wherein like reference characters 26 indicate like parts as above, the combined mold and sealing 27 ring 50 may be formed with a different cross-section from a 28 drop-shape. As shown, the unit 50 may have a rounded leading 29 portion 51 on one side adjacent the conical surface portion 25.
This leading portion 51 merges with the inner peripheral portion 31 23 to define a concave recess therebetween. The cross-section 32 o he unit 50 is suitable for a mold apparatus as described in 1053719 l l 1 U.S. Patent 3,793,427.
2 Referring to Fig. 4, the combined mold element and 3 sealing ring 60 may also be formed with a ring member 61 4 which is of curvilinear cross-section. As shown, the ring mem-ber 61 is in the form of a metal hoop ring member of especially 6 - rigid form, which is particularly favorable for the reception 7 of external as well as internal radial loadings. The ring 8 member 61 is disposed with an exposed surface between the nose 9 portion 28 and outer peripheral portion 27 of the annular body 21. In this way, the ring member 61 is especially suitable 11 for forming an internal support for the socket end in the 12 weakened stretched race-way. The ring member 61 will, in 13 addition, form an effective support for the sealing ring and 14 prevent the unit 60 from being pressed into the annular gap between spigot end and socket end by internal excess pressure 16 in ~ne pipe line, as illustrated in Fig. 10.
17 It is apparent that the ring member 22 can be de- _ 18 signed in various other ways and can be positioned in various 19 ways other than those which are shown in order to be adapted according to existing support means of the mold apparatus or 21 in order to satisfy other demands of the sealing ring, 22 If desired, as shown in Fig. 5, two or more ring members 62 can 23 be combined in one and the same construction and, moreover, 24 such ring members 62 can be connected to each other into a coherent rigid member, for example with separate connectinq 26 webs 63 between the rings 62.
27 Further, as shown in Fig. 6, the combined mold 28 element and sealing ring 70 may be formed with an internal 29 peripheral portion 71 which defines a sealing lip (shown in an unloaded state). In this case, a recess 72 is formed between 31 the sealing lip 71 and the plain portion 41. Thus, instead of 32 forming a compression seal when in place, a lip seal is formed, 1 ~
1~53719 1 As shown in Fig. 8 and lO, pressure areas E are 2 initially formed in the sealing portion 23 of the unit 40 when 3 moving the unit 40 into position on the drift as illustrated 4 in Fig. 7 and, thereafter, are formed in the outer periphery after the hot pipe end is moved over the unit 40, as illu-6 strated in Fig. 8, and hence cooled and shrunk radially 7 towards the unit 40 and the drift 32. In the æ manufacturing 8 stepSof the pipe socket end, the rigid ring member 22 reinforces 9 the unit 40 in order to control the pressure effects involved in the internal as well as in the external parts of the unit 11 40. Referring to Fig. 9, after the socket end and the 12 associated unit 40 are removed from the drift, the pressured 13 areas as illustrated in Fig. 8 are substantially released.
14 The remaining compression as illustrated in areas F assures a good bite and prevents dirt and the like from penetrating into 16 the sealing areas. When moving a spigot end into a socket end, 17 the unit 40 will be compressed similarly to the compression 18 illustrated in the manufacturing step of Fig. 8 and similar 19 pressure areas will arise in the socket end and in the spigot end. Referring to Fig. lO, when a pressure medium is transported 21 through a pressure pipe line incorporating the illustrated 22 pipe joint, the medium is allowed to penetrate into a gap 23 formed between the sealing unit 40 and the socket end. In this 24 latter case, the pressure areas E of the unit 40 are located as indicated in Fig. lO. The effect of the pressure areas 26 provided by the resilient body 21 of the sealing unit 40 in 2~ cooperation with the reinforcing ring member 22 of the sealing 28 unit provides an effective seal against leakage between the 29 socket end and the spigot end of the illustrated pipe line joint.
31 Referring to Fig. ll, a sealing unit 40 can be formed 32 n a mold in a known manner. ~or examplel the unit 40 can be 10~3~19 formed in a cavity 80 formed between three separate, 2 cooperating die parts 81, 82, 83. The manufacturing of the 3 sealing unit 40 is made by locating a prefabricated steel ring 4 member 22 in the cavity 80 on a set of pins 84 which might be withdrawable. Only one pin is illustrated in the drawing in 6 dotted lines. These pins 84 protrude from the internal side of 7 one part 8~ of the die in mutually spaced relation along 8 the internal side of the die part. ~ sy means of such pins, 9 each ring is supported in a rela~i~ely accurate manner in the die to secure accurate reinforcing effects in the unit 40 11 produced therein. Before the produced unit is removed from 12 the die, the pins 84 are withdrawn from the unit and the 13 associated die part. The elasticity of the rubber allows 14 release of the unit 40 from the mold and the pins, even if the pins are permanently connected to the mold surface and are not 16 movable relative thereto.
17 The mold portions are wlthdrawn in directions x, y 18 relative to the unit in order to release the unit 40.
19 All the accompanying Figures of the combined sealing and f~orming element cross-section show the reinforcement placed 21 near the rubber bulk surface. However, the reinforcement can ~5 ~e loc ed ~n spaced relation from the outer surface. ¦
227 ' .
Claims (15)
1. A combined mold element and sealing ring com-prising an annular body of elastically yieldable material, said body having opposite side portions, an inner peripheral surface defining at least one radially inwardly protruding sealing portion located between said opposite side portions, and an outer peripheral surface having an outer radially directed surface portion located between said side portions; and a rigid reinforcing non-elastic member disposed in said body and located in an area defined between said opposite side portions and spaced radially outside said pro-truding sealing portion.
2. A combined mold element and sealing ring as set forth in claim 1 wherein said inner peripheral surface has a plain portion extending from said sealing portion to define a leading edge with said outer peripheral surface.
3. A combined mold element and sealing ring as set forth in claim 1 wherein said inner peripheral surface has a second portion spaced from said sealing portion and defining a leading edge with said outer peripheral surface.
4. A combined mold element and sealing ring as set forth in claim 1 which further includes an obliquely extending leading surface portion at one of said side portions and wherein said reinforcing member is located in said body close to a transition portion between said outer surface portion and said leading surface portion.
5. A combined mold element and sealing ring as set forth in claim 4 wherein a radial plane through the center line of said reinforcing member is located between a radial plane through the sealing portion and a radial plane through said leading surface portion.
6. A combined mold element and sealing ring as set forth in claim 1 which further includes a rear surface portion at the other of said side portions and wherein said member is located close to a concave transition portion between said outer surface portion and said rear surface portion.
7. A combined mold element and sealing ring as set forth in claim 6 wherein a radial plane through the center line of said reinforcing member crosses a main part of said sealing portion.
8. A combined mold element and sealing ring as set forth in claim 1 wherein said reinforcing member is an annular ring of circular cross-section.
9. A combined mold element and sealing ring as set forth in claim 1 wherein said reinforcing member is an annular ring having a curvilinear cross-section.
10. A combined mold element and sealing ring as set forth in claim 1 wherein said reinforcing member includes a pair of annular rings and a plurality of webs connecting said rings together.
11. A combined mold element and sealing ring as set forth in claim 1 wherein said reinforcing member is completely embedded within said body.
12. A combined mold element and sealing ring as set forth in claim 1 wherein said outer peripheral surface includes a nose portion located on one side of said outer radially directed surface portion.
13. A combined mold element and sealing ring as set forth in claim 12 wherein said body includes a rounded leading surface portion on a side opposite said nose portion.
14. A combined mold element and sealing ring as set forth in claim 12 wherein said body includes an obliquely extending leading surface portion on a side opposite said nose portion and a plain surface on said inner peripheral surface defining a leading edge with said leading surface portion.
15. A combined mold element and sealing ring as set forth in claim 1, wherein said sealing portion is rounded and wherein said inner peripheral surface further defines a plain inner portion spaced from said sealing portion;
said element further including an obliquely extending outer surface portion, located adjacent said outer radially directed surface, forming a leading edge with said plain inner portion, said outer radially directed surface portion being rounded, and a rounded nose portion being located adjacent said outer radially directed surface portion on the side opposite said obliquely extending outer surface portion, said reinforcing ring being located between a radial plane passing through the sealing portion and a radial plane passing through said leading edge.
said element further including an obliquely extending outer surface portion, located adjacent said outer radially directed surface, forming a leading edge with said plain inner portion, said outer radially directed surface portion being rounded, and a rounded nose portion being located adjacent said outer radially directed surface portion on the side opposite said obliquely extending outer surface portion, said reinforcing ring being located between a radial plane passing through the sealing portion and a radial plane passing through said leading edge.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/766,516 US4061459A (en) | 1975-08-28 | 1977-02-07 | Combined mold element and sealing ring |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1053719A true CA1053719A (en) | 1979-05-01 |
Family
ID=25076675
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA280,619A Expired CA1053719A (en) | 1977-02-07 | 1977-06-15 | Combined mold element and sealing ring |
Country Status (18)
| Country | Link |
|---|---|
| JP (2) | JPS5399154A (en) |
| AT (1) | AT359340B (en) |
| AU (1) | AU515839B2 (en) |
| BR (1) | BR7800651A (en) |
| CA (1) | CA1053719A (en) |
| DD (1) | DD134136A5 (en) |
| DE (1) | DE2805065C2 (en) |
| DK (1) | DK147771C (en) |
| FI (1) | FI68306C (en) |
| FR (1) | FR2379364A1 (en) |
| GB (1) | GB1585555A (en) |
| IT (1) | IT1155817B (en) |
| MX (1) | MX145826A (en) |
| NL (1) | NL183783C (en) |
| NO (1) | NO145354C (en) |
| SE (1) | SE7801392L (en) |
| SG (1) | SG74584G (en) |
| ZA (1) | ZA789B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5626349A (en) * | 1995-05-22 | 1997-05-06 | N C Rubber Products Inc. | Self-lubricating sealing ring |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL9400894A (en) * | 1994-06-01 | 1996-01-02 | Wavin Bv | Method and apparatus for forming a socket on a tube of biaxially oriented thermoplastic material |
| CN102410418A (en) * | 2011-09-20 | 2012-04-11 | 蔡应麟 | Quick joint capable of preventing water leakage |
| JP2015090210A (en) * | 2013-11-07 | 2015-05-11 | Nok株式会社 | Gasket and seal structure |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3744806A (en) * | 1971-11-22 | 1973-07-10 | Price Brothers Co | Pipe joint seal |
| DE2421786C3 (en) * | 1973-05-07 | 1978-06-15 | Kubota Engineering Co., Ltd., Osaka (Japan) | Socket pipe connection for plastic pipes |
| AU498874B2 (en) * | 1974-09-02 | 1979-03-29 | Rieber + Son A/S | Moulding a pipe end socket |
| JPS5921511B2 (en) * | 1977-09-02 | 1984-05-21 | ニッタン株式会社 | Optical smoke detector with failure detection function |
-
1977
- 1977-04-07 JP JP3995277A patent/JPS5399154A/en active Pending
- 1977-06-14 GB GB24798/77A patent/GB1585555A/en not_active Expired
- 1977-06-15 CA CA280,619A patent/CA1053719A/en not_active Expired
-
1978
- 1978-01-03 ZA ZA00780009A patent/ZA789B/en unknown
- 1978-01-03 AU AU32147/78A patent/AU515839B2/en not_active Expired
- 1978-02-02 BR BR7800651A patent/BR7800651A/en unknown
- 1978-02-03 DD DD78203552A patent/DD134136A5/en unknown
- 1978-02-03 AT AT77578A patent/AT359340B/en not_active IP Right Cessation
- 1978-02-03 MX MX172312A patent/MX145826A/en unknown
- 1978-02-03 IT IT47919/78A patent/IT1155817B/en active
- 1978-02-06 NO NO780398A patent/NO145354C/en unknown
- 1978-02-06 NL NLAANVRAGE7801356,A patent/NL183783C/en not_active IP Right Cessation
- 1978-02-06 DK DK54178A patent/DK147771C/en not_active IP Right Cessation
- 1978-02-07 DE DE2805065A patent/DE2805065C2/en not_active Expired
- 1978-02-07 SE SE7801392A patent/SE7801392L/en unknown
- 1978-02-07 FR FR7803418A patent/FR2379364A1/en active Granted
- 1978-02-07 FI FI780388A patent/FI68306C/en not_active IP Right Cessation
-
1984
- 1984-10-25 SG SG745/84A patent/SG74584G/en unknown
-
1985
- 1985-07-01 JP JP1985100414U patent/JPS6116488U/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5626349A (en) * | 1995-05-22 | 1997-05-06 | N C Rubber Products Inc. | Self-lubricating sealing ring |
Also Published As
| Publication number | Publication date |
|---|---|
| AU515839B2 (en) | 1981-05-07 |
| FI780388A (en) | 1978-08-08 |
| AU3214778A (en) | 1979-07-12 |
| FI68306C (en) | 1985-08-12 |
| NL183783C (en) | 1989-01-16 |
| NL183783B (en) | 1988-08-16 |
| GB1585555A (en) | 1981-03-04 |
| MX145826A (en) | 1982-04-05 |
| JPS6116488U (en) | 1986-01-30 |
| NO145354C (en) | 1982-03-03 |
| JPS5399154A (en) | 1978-08-30 |
| SG74584G (en) | 1985-04-26 |
| SE7801392L (en) | 1978-08-08 |
| FR2379364B1 (en) | 1982-10-29 |
| ATA77578A (en) | 1980-03-15 |
| NO780398L (en) | 1978-08-08 |
| NL7801356A (en) | 1978-08-09 |
| ZA789B (en) | 1978-10-25 |
| DK54178A (en) | 1978-08-08 |
| DE2805065C2 (en) | 1986-09-04 |
| BR7800651A (en) | 1978-09-12 |
| IT1155817B (en) | 1987-01-28 |
| DK147771C (en) | 1985-05-28 |
| NO145354B (en) | 1981-11-23 |
| AT359340B (en) | 1980-11-10 |
| DK147771B (en) | 1984-12-03 |
| IT7847919A0 (en) | 1978-02-03 |
| FI68306B (en) | 1985-04-30 |
| DD134136A5 (en) | 1979-02-07 |
| DE2805065A1 (en) | 1978-08-10 |
| FR2379364A1 (en) | 1978-09-01 |
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