CA1094765A - Tire tread forming method and apparatus - Google Patents
Tire tread forming method and apparatusInfo
- Publication number
- CA1094765A CA1094765A CA282,459A CA282459A CA1094765A CA 1094765 A CA1094765 A CA 1094765A CA 282459 A CA282459 A CA 282459A CA 1094765 A CA1094765 A CA 1094765A
- Authority
- CA
- Canada
- Prior art keywords
- shoes
- members
- uncured elastomer
- annular body
- tread
- 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
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
- B29D30/00—Producing pneumatic or solid tyres or parts thereof
- B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
- B29D30/00—Producing pneumatic or solid tyres or parts thereof
- B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
- B29D30/0601—Vulcanising tyres; Vulcanising presses for tyres
- B29D30/0605—Vulcanising presses characterised by moulds integral with the presses having radially movable sectors
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
- B29D30/00—Producing pneumatic or solid tyres or parts thereof
- B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
- B29D30/0601—Vulcanising tyres; Vulcanising presses for tyres
- B29D30/0606—Vulcanising moulds not integral with vulcanising presses
- B29D30/0629—Vulcanising moulds not integral with vulcanising presses with radially movable sectors
- B29D2030/063—Vulcanising moulds not integral with vulcanising presses with radially movable sectors the moulds being split in upper and lower halves
Abstract
TIRE TREAD FORMING METHOD AND APPARATUS
Abstract of the Disclosure A body having rubber material thereon is positioned on a lower member, and an upper member is moved toward the lower member, such relative movement causing tread-forming shoes to move to inward positions to form a tread on the rubber material. As an alternative, the upper and lower members may be brought together, and rubber material may be injected into position to have a tread formed thereon.
Upon movement of the upper and lower member relatively apart, the rubber material is made to remain in contact with the shoes, and the body is removed, whereupon an annular core having rubber material thereon is disposed on the lower member, and the upper and lower members are again brought together to deposit the rubber material in contact with the shoes onto the rubber material on the core.
Abstract of the Disclosure A body having rubber material thereon is positioned on a lower member, and an upper member is moved toward the lower member, such relative movement causing tread-forming shoes to move to inward positions to form a tread on the rubber material. As an alternative, the upper and lower members may be brought together, and rubber material may be injected into position to have a tread formed thereon.
Upon movement of the upper and lower member relatively apart, the rubber material is made to remain in contact with the shoes, and the body is removed, whereupon an annular core having rubber material thereon is disposed on the lower member, and the upper and lower members are again brought together to deposit the rubber material in contact with the shoes onto the rubber material on the core.
Description
- 10~4765 This invention relates to method and apparatus for forming a tread on a tire, and more particularly, to a method and apparatus wherein tread-forming shoes form a tread on rubber material.
In the formation of a tread on a tire, upper and lower mold portions are provided, each mold portion containing means defining a tread pattern. In one known embodiment, each mold portion contains a rigidly mounted solid ring, which defines the tread pattern, and in another known apparatus, each mold portion contains a resiliently mounted segmented ring (i.e., individual tread shoes). In both systems, it is common practice to initially completely close the two mold portions together, and then to apply fluid pressure to the tire to force the rubber into contact with the tread-forming shoes. The segmented ring design as described above is considered to have a certain advantage over the rigidly mounted solid ring system, since when the mold portions are moved apart to allow removal of the tire, the resiliently mounted shoes move radially outwardly some distance greater than the tread groove depth so that the tire can be removed from the apparatus without distorting the tread.
Since in such conventional systems the tire is inflated and expanded to force the rubber into the tread-forming means, the expansion and forces involved in forming the tread tend to displace radial and circumferential rein~orcements from their ideal positions.
It will be understood that it would be considered advantageous for the tread to be formed on the tire with ~J
10~4765 the tire structure remaining in its ideal position during the formation thereof through isolation of the forces of the reinforcement of the tire.
It will also be understood that, while achieving proper formation of the tread, the method thereof, and the apparatus for achieving such method, should, with advantage, be extremely simple and efficient.
According to one aspect of the invention there is provided in a method of forming ~ tread on a green tire carcass in which uncured elastomer is first deposited onto a peripheral surface of an annular body, then trans-ferred to a pair of members by first moving the members into contact with the uncured elastomer on the annular body and then separating the members with the uncured elastomer adhering thereto from the annular body, and subsequently applied to a tread area of green tire carcass by moving the members to a position at which the uncured elastomer adhering thereto contacts the green tire carcass positioned between the members, the improvement comprising:
said step of transferring the uncured elastomer to the members includes the steps of moving a plurality of tread forming shoes mounted on the members from an outward extended position radially inwardly to an inward retracted position forming a tread on the uncured elastomer, and then moving the shoes and hence the uncured elastomer adhering thereto radially outwardly to an intermediate position between said inward retracted and outward extended position.
According to another aspect of the invention there is provided in a method of forming a tread on a green tire carcass in which uncured elastomer is first injected into a pair of annular cavities individually formed between an annular body and a pair of members for forming a tread pattern in the band of uncured elastomer in the cavities, then retained on the members upon moving the members away from the annular body, and sub-sequently applied to a tread area of a green tire carcass by moving the members to a position at which the uncured elastomer retained on the annular body is applied to the green tire carcass positioned between the members, the improvement comprising: said step of retaining the uncured elastomer on the members includes the steps of moving a plurality of shoes mounted on the members, and hence the uncured elastomer adhering thereto, to an intermediate '1 10~765 position between an inner retracted position and an outward extended posi-tion, and controllably increasing an inner diameter of the band of uncured elastomer adhering to the shoes.
According to a further aspect of the invention there is provided in an apparatus for forming a tread on a green tire carcass, said apparatus including an annular body onto which the uncured elastomer is first deposited, and first and second members movable between a first position at which the members are spaced apart sufficient for positioning the annular body therebetween and a second position at which the members substantially encompass the uncured elastomer on said annular body, each of said members having a plurality of shoes movable between an outward extended position at which the shoes are free from contact with the uncured elastomer on the annular body and an inward retracted position at which the shoes are in contact with the uncured elastomer, the improvement comprising: means for moving the shoes to an intermediate position between said inward retracted and outward extended positions in response to the members being moved from the second position to the first position.
These and other features of the invention will become apparent from a study of the following specification and drawings in which:
1~ 17~;S
FIG. 1 is a front elevatlon of an overall apparatus incorporating the inVention;
FIG. 2 is a side elevation of the apparatus shown in FIG. l;
FIG. 3 is a section view of the main portion of the apparatus of FIGS. 1 and 2;
FIG. 4 is a plan view of the body for use with the apparatus of FIG. 3;
FIG. 5 is a sectional view taken along the line V-V of FIG. 4;
FIG. 6 is a sectional view taken along the line VI-VI of FIG. 4;
FIG. 7 is a sectional view taken along the line VII of FIG. 4;
FIG. 8 is a sectional view taken along the line VIII-VIII of FIG. 4;
FIG. 9 is a sectional view taken along the line IX-IX of FIG. 4;
FIGS. 10-15 are schematic views of the apparatus showing the operation thereof;
FIG. 16 is a view similar to that shown in FIG.
9, but of an alternate embodiment of body;
FIGS. 17-19 are schematic views of an alternate embodiment of apparatus showing the operation thereof; and FIG. 20 is a schematic view of yet another embodiment of the apparatus showing the operation thereof.
Description of the Preferred Embodiment Shown in FIGS. 1 and 2 is the overall apparatus 20 incorporating the invention. As shown therein, a beam structure 22 has fixed thereto the body 24 of a cylinder .~
10~765 26, with the rod end 28 thereof extending downwardly therefrom. The rod end 28 has fixed thereto a plate members 30,32 having respective eyes 34 mounted thereto. A
first or upper member 36 has eyes 38 mounted to the upper surface 40 thereof, and chains 42 interconnect the eyes 34 and eyes 38 as shown in FIGS. 1 and 2. It is to be understood that through extension and retraction of the rod 28 of the cylinder 26, the plate members 30,32 are lowered and raised to turn lower and raise the upper member 36.
A lower member 44 is mounted to a frame 46 which in turn rests on the floor. Details of the upper and lower members 36, 44 are best shown in FIG. 3.
As shown in such FIG. 3, the lower member 44 defines an annular recess 46, the outer surface 48 of which is angled downwardly and inwardly of the member to define a ramp surface. In contact with such ramp surface 48 are six tread-forming shoes 50, spaced about the annular recess 46.
The upper member 36 also defines an annular recess 52, with the outer ramp surface 54 thereof tapered upwardly and inwardly of the member 36 as shown in FIG. 3, and further included are six tread-forming shoes 56 positioned in contact with the ramp surface 54, and spaced about the annular recess 52 of the member 36. The tread-forming shoes 56 are retained for sliding movement along the ramp surface 54 by means of angled bolt structures 58. Each bolt structure 58 includes a bolt 59 disposed through a stepped bore 60 defined b~ a shoe 56, and having the end thereof in threaded engagement with the member 36. A
sleeve 61 is disposed about the holt 59, in contact with the member 36 and extending to the step 65 in the bore 60.
lOg'~765 A washer 67 rests on the step 65 and the sleeve 61, forced thereon by the head 69 of the bolt 59. The tread-for~.ing shoes 50 are also mounted to the member 44 in the same manner. It will be seen that through such mounting of the tread-forming shoes 56 to the member 36, the tread-forming shoes 56 are movable to outward, extended positions relative to the member 36, and inward, retracted positions relative to the member 36. Similarly, the tread-formin~
shoes 50 are movable to outward, extended positions relative to the member 44, and inward, retracted positions relative to the member 44.
Resilient springs 62 interconnect the member 44 and tread-forming shoes 50 for resiliently biasing the tread-forming shoes 50 in their outward, extended positions. Similarly, resilient springs 64 interconnect the member 36 and tread-forming shoes 56 in the outward extended positions thereof.
As shown in FIG. 3, each of the tread shoes 50 defines a recess 66 which may be generally aligned with an opening 68 in the member 44 upon movement of tread shoes 50 from their outward, extended positions toward the inward, retracted positions thereof. Upon such general alignment of the recess 66 and opening 68, an elongated shaft 70 in the form of a bolt may be positioned through each generally aligned opening 68 and 66, whereby the tread-forming shoes 50 are limited in movement under the urging of the springs 62 toward the outer, extended positions thereof, to positions between the outward, extended and inward, retracted positions thereof. The tread-forming shoes 56 and member 36 include a similar structure so selectively 10~7~5 limiting the moYement of the tread-for~;ing shoes 56 under the urging of the resilient springs 64 toward the outward, extended positions thereof.
A body 72 for use with the structure as thus far described is shown in FIGS. 4-9. As shown therein the body 72 is made up of a disc 73 (FIG. 5) having portions 75, 77 fixed to the opposite sides thereof. Two circular rings 79, 81 are resiliently mounted to opposite sides of the disc 73. The rings 79, 81 and outer portion of the disc 73 define a rib 76. The body 72 is thus made up of a generally annular main body portion 74, and a rib 76 positioned about the outer periphery of the generally annular main body portion 74. Fixed to the outer periphery of the rib are ears 78, positioned on opposite sides of the body 72. The utility of such ears 78 will be described in detail further on.
As best shown in FIG. 5, the body 72 defines a passage 80 extending from the outer periphery of the rib 76 to inside the body 72, communicating with an annular passage 82 defined within the body 72. Yet another annular passage 84 is defined by the body 72, and the two annular passages 82, 84 are connected by a cross passage 86. The annuiar passage 84, as shown in FIG. 6, communicated with yet another passage 88 extending to the outer periphery of the rib 76.
It will be seen that cooling liquid can be introduced into the passage 80, to circulate about and through annular passage 82, through cross passage 86, into annular passage 84, and from the annular passage 84 through the passage 88.
10~4765 As best shown in FIGS. 7 and 9, yet another passage 90 extends from the outer periphery of the rib 76 to a third, smaller annular passage 92 defined by the body 72. The hody 72 has movably mounted thereto a plurality of poppet valve members 94, each resiliently biased by a spring 96 into a position wherein the outer head surface 98 thereof is generally flush with the outer surface 100 of the main body portion 74, i.e., with the valve members 94 in their retracted positions. The valve members 94 are movable against the resilience of the springs 96 to extended positions wherein the outer head surfaces 98 thereof are extended from the surface 100 of the main body portion 74. Fach of the poppet valve members 94 is movable in a cha~ber 102, a portion of which is defined by a portion of the inner head surface 104 of the poppet valve member 94, and each such chamber 102 communicates with the annular passage 92 through a passage 106. It will be seen that application of pressurized air to the passage 90 results in the fact that pressurized air is communicated to the annular passage 92, through the passages 106, and into the chambers 102 to move the valve members 94 to extended positions, wherein the outer head surfaces 98 thereof are extended from the surface 100 of the main body portion 74.
Yet another passage 108 (FIG. 4), similar to passage 80, but communicating with another internal annular passage 110 defined by the body 72, is used in a similar manner to actuate another plurality of poppet valve members 112 in the same manner.
Fixed to the lower surface 113 of the member 44 are the bodies 114 of a plurality of cylinders 116 (FIGS. 1 and 2~, the rods 118 of which extend through flange ~0947fiS
portions 120, 122, defined by the member 44 and beyond the upper surface 124 thereof. Each rod 118 has secured thereto an elongated locking lug 126 which may be positioned, by turning of the rod 118 about the longi-tudinal axis thereof, through a respective elongated opening 128 defined by a flange 130 of the member 36. It will be seen that upon relative movement of the members 36, 44 together (FIGS. 1 and 2), the properly positioned locking lugs 126 are allowed to pass through the respective openings 123 in the flange 130. Then the individual locking lugs 126 may be turned to an extent so that upon the downward movement of the rods 118 of the cylinders 116, the locking lugs 126 contact portions of the upper surface 132 of the flange 130 to draw the members 36, 44 together with relatively great force. The cylinders 116 may, of course, be actuated in a well known manner, for example, being set up as slave cylinders responsive to actuation of a master cylinder (not shown).
In the use of the apparatus, the body 72 is lifted by means of a fork lift truck (not shown), the arms o the fork being in contact with the undersides of the ears 78 for proper transport thereof. The body 72 is moved to an oven and uncured rubber material is disposed in two strips 134, 136 about the body, the rubber being positioned on the main body portion 74 adjacent one and the other sides 140, 138 of the rib 76 (see FIG. 10). The fork lift truck then moves the body 72 with the rubber 134, 136 thereon to adjacent the upper and lower members 36, 44.
The fork lift truck then deposits the body 7~ onto the member 44. During this time, the tread-forming shoes 50, 56 are in their fully extended positions, and are being ~0~?4765 heated ~y application of heated fluid through passage means defined by the members 36, 44. The rib 76 is positioned so that one side 140 thereof is in contact with the tread-for~ing shoes 50 (see FIG. 10). The fork lift truck is then remoYed from the area of the members 36, 44. The member 36 is lowered relative to the member 4~ by means of cylinder 26, so that the locking lugs 126 pass through the apertures 128. The locking lugs 126 are then rotated to be in position so that retraction of the rods 118 of the cylinders 116 will draw the member 36 to the member 44.
During such downward movement of the member 36, the tread-forming shoes 56 have been brought into contact with the other side 138 of the rib 76.
The cylinders 116 are then actuated to move the member 36 toward the member 44 (~IG. 11), the cylinder 36, of course, being extended sufficiently to allow enough slack in the chains 42 for such further drawing down of the member 36. Upon such further movement of the member 36, with the tread-forming shoes 50, 56 in contact with the opposite sides 140, 138 of the rib 76, it will be seen that further movement of the members 36, 44 together provides a relatiye movement of the tread-forming shoes 50, 56 and body 72 such that the tread-forming shoes 50, 56 move along the surfaces of the sides 140, 138 of the body 72 into contact with the rubber material 134, 136 on the body 72 with such relative movement being determined by the configurations of the sides 140, 138. Thereby, the tread-forming shoes 50, 56 are hrought into contact with the rubber material 134, 136. That is, the movement of the tread-forming shoes 50, 56 and body 72 relatively takes place as if the body 72 were being held in a position, and 10~`176S
the shoes 50, 56 were being slid along the sides 140, 138 of the rib 76, so that proper formation of the tread on the rubber material 134, 136 is provided.
During this process, cooling fluid is introduced into the passage 80 to flow through the annular passages 82, 84 and from the body 72 to provide a proper operatin~
temperature of the body 72. Since the tread-forming shoes 50, 56 are in a heated state, the rubber material 34, 136 will tend to stick to such shoes rather than the cooled body 72.
With the members 36, 44 positioned as shown in FIG. 11, bolts 70 are inserted in the openings and recesses 68, 66 to limit movement of the tread-forming shoes 50, 56 under the urging of the springs 72, 74 toward the outer, extended positions thereof, to positions between the outward, extended and inward, retracted positions thereof.
The member 36 is moved a small distance from the member 44, and the tread-forming shoes 50, 56 are moved toward their outward, extended positions, being limited by the bolts 70 as described above. The tread-forming shoes 50, 56 are thereby moved only a slight distance from the body 72, still in contact with the rubber material 134, 136. At this point, air is introduced into the passages 90, 108 to actuate the poppet valve members 94, 112, so that the outer head surfaces thereof extend beyond the outer surface 100 of the body portion 74, permitting air to force the rubber material 134, 136 from the body 72. It is thereby insured that the rubber material 134, 136 remains in contact with the tread-forming shoes 50, 56~ and not in contact with the body 72.
10~765 Subsequently, the member 36 is remoYed further from the member 44 ~FIG. 12), and the bod~ 72 is removed from the members 36, 4~.
FIG. 13 shows an annular core 150 having rubber material 152 already deposited thereon disposed on the member 44. Again, the member 36 is brought to adjacent the member 44 in this case, until the tread shoes 56 contact the tread shoes 50. At this point, it will be seen that further relative movement of the members 36, 44 together, through actuation of the cylinders 116 as above described, moves the rubber material 134, 136 in contact with the tread-forming shoes 50, 56 into contact with the rubber material 152 on the annular core 150 (see FIG. 14). The uncured rubber material 134, 136 in contact with the tread-forming shoes 50, 56 is brought into contact with the rubber material 152 positioned on the core 150 through movement of the tread-forming shoes 50, 56 toward the inward, retracted positions thereof. When the tread-forming shoes have reached the inward retracted position, the bolts 70 are removed and after curing the entire rubber material the member 36 is then removed from the member 44 as described above, allowing the tread-forming shoes 50, 56 to move under the resilience of the springs 62, 64 to their fully outward, extended positions as shown in FIG. 15, leaving a tire made up of rubber material having a tread formed thereon, disposed on a core 150.
A portion of an alternate embodiment of body 200 is shown in FIG. 16. As shown therein, the overall construction of the body 200 is generally similar to the body 72 with particular reference to FIG. 9. As shown in FIG. 16, the body 200 is made of a disc 202 having portions i ' " 10~?4765 204, 206 fixed to opposite sides thereof. This generally ma~es up an annular main body portion 208, and moYable body members 210, 212 in the form of rings are movably mounted to the main body portion 208, making up with a portion of the disc 202 a rib 209. Resilient elastomeric members 214, 216 are interposed the rings 210, 212 and disc 202, so that the rings 210, 212 are resiliently urged away from the opposite sides of the disc 202. The inner peripheries 218, 220 of the respective rings 210, 212 are quite adjacent the ln outer surface 221, 223 of the main body portion 208.
The ring 210 defines a plurality of passages therethrough (one shown at 222) and likewise the ring 212 defines a plurality of passages therethrough (one shown at 224~. These passages lead from adjacent an annular depression 226 defined by the body portion 208 and another annular depression 228 defined by the body portion 208.
Additional rings 232, 234 are movably mounted to opposite sides of the body 200, resiliently bound by spring means 236 to their outward positions, similar to the previous embodiment of FIG. 5.
In the use of such apparatus, the tread-forming shoes as previously described bear on the rings 210, 212, compressing the elastomeric members 214, 216 under the force of such shoes, with the body in the general position shown in, for example, FIG. 11. In such state, as the tread-forming shoes form tread on elastomeric material on the surface 221 of the body 200 and the surface 223 of the body 2Q0, excess elastomeric material will be caused to flow under the force of the shoes into the annular depressions 226, through the passaaes 222 in the ring 210 and generally from the apparatus. Likewise, elastomeric 10~47~5 material will flow into the annular depressicn 228 and through the passage 224 in the ring 212 and generally from the apparatus. The rings 232, 234, being in contact with the shoes, act as dams to retain elastomeric material in the proper areas. Thus, it will be seen that flow of elastomeric material during the tread-forming operation is allowed for in the embodiment shown in FIG. 16, so that it is insured that any material forced from the tread-forming areas is allowed to flow relatively free therefrom.
In the event that too much elastomeric material has initially been applied to the body 200, the resilience of the spring means 236 will be overcome, allowing excess elastomeric material to flow past the edge of the rings 232, 234.
After insertion of the bolts 70~ and upon the lifting of the member 36 from the member 44 (similar to that shown in FIG. 12), the force compressing the elastomeric members 214, 216 is removed from the rings 210, 212, allowing the rings 210, 212 to move to positions wherein communication is no longer provided between the area 230 of the body 200 and the annular depression 226, or the area 231 of the body 200 and the annular depression 228. As the rings 210, 212 move under the resilience of the elastomeric members 214, 216, the edges of the rings 210, 212 at the inner peripheries 218, 220 thereof adjacent the main hody portion 208 act as cutting members to cut off the elastomeric material which has flowed from the tread-forming area 230, 231, into the annular depressions 226, 228 leaving elastomeric material on the body 200 of proper shape and size with proper tread formed thereon. This cutting operation is insured during such removal of the ~0~7~;S
member 36 from the member 44 since the elasto~eric members 214, 216 resiliently bias the rings 210, 212 towards positions blocking flow o~ elastomeric material from the areas 230, 231, through the passages 222, 224.
As yet another alternative elastomeric material need not be initially applied to a hody adjacent one and the other sides thereof in accordance with FIGS. 10-11.
Rather, as shown in FIG. 17, the body 300 may be provided with a plurality of upper passages 302, and a plurality of lower passages 304, all communicating with a main conduit 306 in turn communicating with the head end 308 of a cylinder 310. In such system, the first and second members 36, 44 are brought together prior to the introduction of any elastomeric material on which tread i5 to be formed (~IG. 18), and then the cylinder 310 is actuated so that elastomeric material 312 is injected through the conduit 306, through the passages 302, 304 in the body 300, and onto the body 300, and into the cavity defined by the surfaces of the body 300 and the surfaces of the tread-forming shoes 50, 56, meanwhile with such elastomericmaterial having tread formed thereon during such operation.
The member 36 may be subsequently removed from the member 44 after insertion of the bolts 70, as shown in FIG. 19, whereupon elastomeric material 314, 316 remains on the shoes 56, and on the shoes 50, in accordance with the previous embodiment. Subsequent steps in this method are identical to those shown in FIGS. 13-15.
As yet another embodiment, the member 36' is provided with passages 350, 352 which communicate with conduits 354, 356 which in turn com~.unicate with a main conduit 358, communicating ~ith the head end 360 of a cylinder 362.
~0~ ~765 Likewise, the member 44' is provided with passages 364, 366 which communicate with conduits 368, 37Q which in turn communicate with a conduit 372 in turn communicating with the head end 374 of another cylinder 376. The cylinders 362, 376 are filled with elastomeric material 378 which is made to flow into the appropriate tread-forming areas, through the member 36' and member 44' with the members 36', 44' already brought together, and without the body 72, having had previously applied thereto any elastomeric 10 material.
In yet another method, it will be understood that a portion of the elastomeric material can be initially applied to the body 72, and the remaining necessary elastomeric material may be applied through the method in accordance with FIGS. 17-19 or the method in accordance with FIG. 20.
While both embodiments described include a centerparting mold apparatus, it is to be understood that the parting line of the mold portions need not be substantially at the center of the overall apparatus, but can be spaced therefrom, i.e., the mold apparatus could be of the edgeparting or shoulder-parting type.
In the formation of a tread on a tire, upper and lower mold portions are provided, each mold portion containing means defining a tread pattern. In one known embodiment, each mold portion contains a rigidly mounted solid ring, which defines the tread pattern, and in another known apparatus, each mold portion contains a resiliently mounted segmented ring (i.e., individual tread shoes). In both systems, it is common practice to initially completely close the two mold portions together, and then to apply fluid pressure to the tire to force the rubber into contact with the tread-forming shoes. The segmented ring design as described above is considered to have a certain advantage over the rigidly mounted solid ring system, since when the mold portions are moved apart to allow removal of the tire, the resiliently mounted shoes move radially outwardly some distance greater than the tread groove depth so that the tire can be removed from the apparatus without distorting the tread.
Since in such conventional systems the tire is inflated and expanded to force the rubber into the tread-forming means, the expansion and forces involved in forming the tread tend to displace radial and circumferential rein~orcements from their ideal positions.
It will be understood that it would be considered advantageous for the tread to be formed on the tire with ~J
10~4765 the tire structure remaining in its ideal position during the formation thereof through isolation of the forces of the reinforcement of the tire.
It will also be understood that, while achieving proper formation of the tread, the method thereof, and the apparatus for achieving such method, should, with advantage, be extremely simple and efficient.
According to one aspect of the invention there is provided in a method of forming ~ tread on a green tire carcass in which uncured elastomer is first deposited onto a peripheral surface of an annular body, then trans-ferred to a pair of members by first moving the members into contact with the uncured elastomer on the annular body and then separating the members with the uncured elastomer adhering thereto from the annular body, and subsequently applied to a tread area of green tire carcass by moving the members to a position at which the uncured elastomer adhering thereto contacts the green tire carcass positioned between the members, the improvement comprising:
said step of transferring the uncured elastomer to the members includes the steps of moving a plurality of tread forming shoes mounted on the members from an outward extended position radially inwardly to an inward retracted position forming a tread on the uncured elastomer, and then moving the shoes and hence the uncured elastomer adhering thereto radially outwardly to an intermediate position between said inward retracted and outward extended position.
According to another aspect of the invention there is provided in a method of forming a tread on a green tire carcass in which uncured elastomer is first injected into a pair of annular cavities individually formed between an annular body and a pair of members for forming a tread pattern in the band of uncured elastomer in the cavities, then retained on the members upon moving the members away from the annular body, and sub-sequently applied to a tread area of a green tire carcass by moving the members to a position at which the uncured elastomer retained on the annular body is applied to the green tire carcass positioned between the members, the improvement comprising: said step of retaining the uncured elastomer on the members includes the steps of moving a plurality of shoes mounted on the members, and hence the uncured elastomer adhering thereto, to an intermediate '1 10~765 position between an inner retracted position and an outward extended posi-tion, and controllably increasing an inner diameter of the band of uncured elastomer adhering to the shoes.
According to a further aspect of the invention there is provided in an apparatus for forming a tread on a green tire carcass, said apparatus including an annular body onto which the uncured elastomer is first deposited, and first and second members movable between a first position at which the members are spaced apart sufficient for positioning the annular body therebetween and a second position at which the members substantially encompass the uncured elastomer on said annular body, each of said members having a plurality of shoes movable between an outward extended position at which the shoes are free from contact with the uncured elastomer on the annular body and an inward retracted position at which the shoes are in contact with the uncured elastomer, the improvement comprising: means for moving the shoes to an intermediate position between said inward retracted and outward extended positions in response to the members being moved from the second position to the first position.
These and other features of the invention will become apparent from a study of the following specification and drawings in which:
1~ 17~;S
FIG. 1 is a front elevatlon of an overall apparatus incorporating the inVention;
FIG. 2 is a side elevation of the apparatus shown in FIG. l;
FIG. 3 is a section view of the main portion of the apparatus of FIGS. 1 and 2;
FIG. 4 is a plan view of the body for use with the apparatus of FIG. 3;
FIG. 5 is a sectional view taken along the line V-V of FIG. 4;
FIG. 6 is a sectional view taken along the line VI-VI of FIG. 4;
FIG. 7 is a sectional view taken along the line VII of FIG. 4;
FIG. 8 is a sectional view taken along the line VIII-VIII of FIG. 4;
FIG. 9 is a sectional view taken along the line IX-IX of FIG. 4;
FIGS. 10-15 are schematic views of the apparatus showing the operation thereof;
FIG. 16 is a view similar to that shown in FIG.
9, but of an alternate embodiment of body;
FIGS. 17-19 are schematic views of an alternate embodiment of apparatus showing the operation thereof; and FIG. 20 is a schematic view of yet another embodiment of the apparatus showing the operation thereof.
Description of the Preferred Embodiment Shown in FIGS. 1 and 2 is the overall apparatus 20 incorporating the invention. As shown therein, a beam structure 22 has fixed thereto the body 24 of a cylinder .~
10~765 26, with the rod end 28 thereof extending downwardly therefrom. The rod end 28 has fixed thereto a plate members 30,32 having respective eyes 34 mounted thereto. A
first or upper member 36 has eyes 38 mounted to the upper surface 40 thereof, and chains 42 interconnect the eyes 34 and eyes 38 as shown in FIGS. 1 and 2. It is to be understood that through extension and retraction of the rod 28 of the cylinder 26, the plate members 30,32 are lowered and raised to turn lower and raise the upper member 36.
A lower member 44 is mounted to a frame 46 which in turn rests on the floor. Details of the upper and lower members 36, 44 are best shown in FIG. 3.
As shown in such FIG. 3, the lower member 44 defines an annular recess 46, the outer surface 48 of which is angled downwardly and inwardly of the member to define a ramp surface. In contact with such ramp surface 48 are six tread-forming shoes 50, spaced about the annular recess 46.
The upper member 36 also defines an annular recess 52, with the outer ramp surface 54 thereof tapered upwardly and inwardly of the member 36 as shown in FIG. 3, and further included are six tread-forming shoes 56 positioned in contact with the ramp surface 54, and spaced about the annular recess 52 of the member 36. The tread-forming shoes 56 are retained for sliding movement along the ramp surface 54 by means of angled bolt structures 58. Each bolt structure 58 includes a bolt 59 disposed through a stepped bore 60 defined b~ a shoe 56, and having the end thereof in threaded engagement with the member 36. A
sleeve 61 is disposed about the holt 59, in contact with the member 36 and extending to the step 65 in the bore 60.
lOg'~765 A washer 67 rests on the step 65 and the sleeve 61, forced thereon by the head 69 of the bolt 59. The tread-for~.ing shoes 50 are also mounted to the member 44 in the same manner. It will be seen that through such mounting of the tread-forming shoes 56 to the member 36, the tread-forming shoes 56 are movable to outward, extended positions relative to the member 36, and inward, retracted positions relative to the member 36. Similarly, the tread-formin~
shoes 50 are movable to outward, extended positions relative to the member 44, and inward, retracted positions relative to the member 44.
Resilient springs 62 interconnect the member 44 and tread-forming shoes 50 for resiliently biasing the tread-forming shoes 50 in their outward, extended positions. Similarly, resilient springs 64 interconnect the member 36 and tread-forming shoes 56 in the outward extended positions thereof.
As shown in FIG. 3, each of the tread shoes 50 defines a recess 66 which may be generally aligned with an opening 68 in the member 44 upon movement of tread shoes 50 from their outward, extended positions toward the inward, retracted positions thereof. Upon such general alignment of the recess 66 and opening 68, an elongated shaft 70 in the form of a bolt may be positioned through each generally aligned opening 68 and 66, whereby the tread-forming shoes 50 are limited in movement under the urging of the springs 62 toward the outer, extended positions thereof, to positions between the outward, extended and inward, retracted positions thereof. The tread-forming shoes 56 and member 36 include a similar structure so selectively 10~7~5 limiting the moYement of the tread-for~;ing shoes 56 under the urging of the resilient springs 64 toward the outward, extended positions thereof.
A body 72 for use with the structure as thus far described is shown in FIGS. 4-9. As shown therein the body 72 is made up of a disc 73 (FIG. 5) having portions 75, 77 fixed to the opposite sides thereof. Two circular rings 79, 81 are resiliently mounted to opposite sides of the disc 73. The rings 79, 81 and outer portion of the disc 73 define a rib 76. The body 72 is thus made up of a generally annular main body portion 74, and a rib 76 positioned about the outer periphery of the generally annular main body portion 74. Fixed to the outer periphery of the rib are ears 78, positioned on opposite sides of the body 72. The utility of such ears 78 will be described in detail further on.
As best shown in FIG. 5, the body 72 defines a passage 80 extending from the outer periphery of the rib 76 to inside the body 72, communicating with an annular passage 82 defined within the body 72. Yet another annular passage 84 is defined by the body 72, and the two annular passages 82, 84 are connected by a cross passage 86. The annuiar passage 84, as shown in FIG. 6, communicated with yet another passage 88 extending to the outer periphery of the rib 76.
It will be seen that cooling liquid can be introduced into the passage 80, to circulate about and through annular passage 82, through cross passage 86, into annular passage 84, and from the annular passage 84 through the passage 88.
10~4765 As best shown in FIGS. 7 and 9, yet another passage 90 extends from the outer periphery of the rib 76 to a third, smaller annular passage 92 defined by the body 72. The hody 72 has movably mounted thereto a plurality of poppet valve members 94, each resiliently biased by a spring 96 into a position wherein the outer head surface 98 thereof is generally flush with the outer surface 100 of the main body portion 74, i.e., with the valve members 94 in their retracted positions. The valve members 94 are movable against the resilience of the springs 96 to extended positions wherein the outer head surfaces 98 thereof are extended from the surface 100 of the main body portion 74. Fach of the poppet valve members 94 is movable in a cha~ber 102, a portion of which is defined by a portion of the inner head surface 104 of the poppet valve member 94, and each such chamber 102 communicates with the annular passage 92 through a passage 106. It will be seen that application of pressurized air to the passage 90 results in the fact that pressurized air is communicated to the annular passage 92, through the passages 106, and into the chambers 102 to move the valve members 94 to extended positions, wherein the outer head surfaces 98 thereof are extended from the surface 100 of the main body portion 74.
Yet another passage 108 (FIG. 4), similar to passage 80, but communicating with another internal annular passage 110 defined by the body 72, is used in a similar manner to actuate another plurality of poppet valve members 112 in the same manner.
Fixed to the lower surface 113 of the member 44 are the bodies 114 of a plurality of cylinders 116 (FIGS. 1 and 2~, the rods 118 of which extend through flange ~0947fiS
portions 120, 122, defined by the member 44 and beyond the upper surface 124 thereof. Each rod 118 has secured thereto an elongated locking lug 126 which may be positioned, by turning of the rod 118 about the longi-tudinal axis thereof, through a respective elongated opening 128 defined by a flange 130 of the member 36. It will be seen that upon relative movement of the members 36, 44 together (FIGS. 1 and 2), the properly positioned locking lugs 126 are allowed to pass through the respective openings 123 in the flange 130. Then the individual locking lugs 126 may be turned to an extent so that upon the downward movement of the rods 118 of the cylinders 116, the locking lugs 126 contact portions of the upper surface 132 of the flange 130 to draw the members 36, 44 together with relatively great force. The cylinders 116 may, of course, be actuated in a well known manner, for example, being set up as slave cylinders responsive to actuation of a master cylinder (not shown).
In the use of the apparatus, the body 72 is lifted by means of a fork lift truck (not shown), the arms o the fork being in contact with the undersides of the ears 78 for proper transport thereof. The body 72 is moved to an oven and uncured rubber material is disposed in two strips 134, 136 about the body, the rubber being positioned on the main body portion 74 adjacent one and the other sides 140, 138 of the rib 76 (see FIG. 10). The fork lift truck then moves the body 72 with the rubber 134, 136 thereon to adjacent the upper and lower members 36, 44.
The fork lift truck then deposits the body 7~ onto the member 44. During this time, the tread-forming shoes 50, 56 are in their fully extended positions, and are being ~0~?4765 heated ~y application of heated fluid through passage means defined by the members 36, 44. The rib 76 is positioned so that one side 140 thereof is in contact with the tread-for~ing shoes 50 (see FIG. 10). The fork lift truck is then remoYed from the area of the members 36, 44. The member 36 is lowered relative to the member 4~ by means of cylinder 26, so that the locking lugs 126 pass through the apertures 128. The locking lugs 126 are then rotated to be in position so that retraction of the rods 118 of the cylinders 116 will draw the member 36 to the member 44.
During such downward movement of the member 36, the tread-forming shoes 56 have been brought into contact with the other side 138 of the rib 76.
The cylinders 116 are then actuated to move the member 36 toward the member 44 (~IG. 11), the cylinder 36, of course, being extended sufficiently to allow enough slack in the chains 42 for such further drawing down of the member 36. Upon such further movement of the member 36, with the tread-forming shoes 50, 56 in contact with the opposite sides 140, 138 of the rib 76, it will be seen that further movement of the members 36, 44 together provides a relatiye movement of the tread-forming shoes 50, 56 and body 72 such that the tread-forming shoes 50, 56 move along the surfaces of the sides 140, 138 of the body 72 into contact with the rubber material 134, 136 on the body 72 with such relative movement being determined by the configurations of the sides 140, 138. Thereby, the tread-forming shoes 50, 56 are hrought into contact with the rubber material 134, 136. That is, the movement of the tread-forming shoes 50, 56 and body 72 relatively takes place as if the body 72 were being held in a position, and 10~`176S
the shoes 50, 56 were being slid along the sides 140, 138 of the rib 76, so that proper formation of the tread on the rubber material 134, 136 is provided.
During this process, cooling fluid is introduced into the passage 80 to flow through the annular passages 82, 84 and from the body 72 to provide a proper operatin~
temperature of the body 72. Since the tread-forming shoes 50, 56 are in a heated state, the rubber material 34, 136 will tend to stick to such shoes rather than the cooled body 72.
With the members 36, 44 positioned as shown in FIG. 11, bolts 70 are inserted in the openings and recesses 68, 66 to limit movement of the tread-forming shoes 50, 56 under the urging of the springs 72, 74 toward the outer, extended positions thereof, to positions between the outward, extended and inward, retracted positions thereof.
The member 36 is moved a small distance from the member 44, and the tread-forming shoes 50, 56 are moved toward their outward, extended positions, being limited by the bolts 70 as described above. The tread-forming shoes 50, 56 are thereby moved only a slight distance from the body 72, still in contact with the rubber material 134, 136. At this point, air is introduced into the passages 90, 108 to actuate the poppet valve members 94, 112, so that the outer head surfaces thereof extend beyond the outer surface 100 of the body portion 74, permitting air to force the rubber material 134, 136 from the body 72. It is thereby insured that the rubber material 134, 136 remains in contact with the tread-forming shoes 50, 56~ and not in contact with the body 72.
10~765 Subsequently, the member 36 is remoYed further from the member 44 ~FIG. 12), and the bod~ 72 is removed from the members 36, 4~.
FIG. 13 shows an annular core 150 having rubber material 152 already deposited thereon disposed on the member 44. Again, the member 36 is brought to adjacent the member 44 in this case, until the tread shoes 56 contact the tread shoes 50. At this point, it will be seen that further relative movement of the members 36, 44 together, through actuation of the cylinders 116 as above described, moves the rubber material 134, 136 in contact with the tread-forming shoes 50, 56 into contact with the rubber material 152 on the annular core 150 (see FIG. 14). The uncured rubber material 134, 136 in contact with the tread-forming shoes 50, 56 is brought into contact with the rubber material 152 positioned on the core 150 through movement of the tread-forming shoes 50, 56 toward the inward, retracted positions thereof. When the tread-forming shoes have reached the inward retracted position, the bolts 70 are removed and after curing the entire rubber material the member 36 is then removed from the member 44 as described above, allowing the tread-forming shoes 50, 56 to move under the resilience of the springs 62, 64 to their fully outward, extended positions as shown in FIG. 15, leaving a tire made up of rubber material having a tread formed thereon, disposed on a core 150.
A portion of an alternate embodiment of body 200 is shown in FIG. 16. As shown therein, the overall construction of the body 200 is generally similar to the body 72 with particular reference to FIG. 9. As shown in FIG. 16, the body 200 is made of a disc 202 having portions i ' " 10~?4765 204, 206 fixed to opposite sides thereof. This generally ma~es up an annular main body portion 208, and moYable body members 210, 212 in the form of rings are movably mounted to the main body portion 208, making up with a portion of the disc 202 a rib 209. Resilient elastomeric members 214, 216 are interposed the rings 210, 212 and disc 202, so that the rings 210, 212 are resiliently urged away from the opposite sides of the disc 202. The inner peripheries 218, 220 of the respective rings 210, 212 are quite adjacent the ln outer surface 221, 223 of the main body portion 208.
The ring 210 defines a plurality of passages therethrough (one shown at 222) and likewise the ring 212 defines a plurality of passages therethrough (one shown at 224~. These passages lead from adjacent an annular depression 226 defined by the body portion 208 and another annular depression 228 defined by the body portion 208.
Additional rings 232, 234 are movably mounted to opposite sides of the body 200, resiliently bound by spring means 236 to their outward positions, similar to the previous embodiment of FIG. 5.
In the use of such apparatus, the tread-forming shoes as previously described bear on the rings 210, 212, compressing the elastomeric members 214, 216 under the force of such shoes, with the body in the general position shown in, for example, FIG. 11. In such state, as the tread-forming shoes form tread on elastomeric material on the surface 221 of the body 200 and the surface 223 of the body 2Q0, excess elastomeric material will be caused to flow under the force of the shoes into the annular depressions 226, through the passaaes 222 in the ring 210 and generally from the apparatus. Likewise, elastomeric 10~47~5 material will flow into the annular depressicn 228 and through the passage 224 in the ring 212 and generally from the apparatus. The rings 232, 234, being in contact with the shoes, act as dams to retain elastomeric material in the proper areas. Thus, it will be seen that flow of elastomeric material during the tread-forming operation is allowed for in the embodiment shown in FIG. 16, so that it is insured that any material forced from the tread-forming areas is allowed to flow relatively free therefrom.
In the event that too much elastomeric material has initially been applied to the body 200, the resilience of the spring means 236 will be overcome, allowing excess elastomeric material to flow past the edge of the rings 232, 234.
After insertion of the bolts 70~ and upon the lifting of the member 36 from the member 44 (similar to that shown in FIG. 12), the force compressing the elastomeric members 214, 216 is removed from the rings 210, 212, allowing the rings 210, 212 to move to positions wherein communication is no longer provided between the area 230 of the body 200 and the annular depression 226, or the area 231 of the body 200 and the annular depression 228. As the rings 210, 212 move under the resilience of the elastomeric members 214, 216, the edges of the rings 210, 212 at the inner peripheries 218, 220 thereof adjacent the main hody portion 208 act as cutting members to cut off the elastomeric material which has flowed from the tread-forming area 230, 231, into the annular depressions 226, 228 leaving elastomeric material on the body 200 of proper shape and size with proper tread formed thereon. This cutting operation is insured during such removal of the ~0~7~;S
member 36 from the member 44 since the elasto~eric members 214, 216 resiliently bias the rings 210, 212 towards positions blocking flow o~ elastomeric material from the areas 230, 231, through the passages 222, 224.
As yet another alternative elastomeric material need not be initially applied to a hody adjacent one and the other sides thereof in accordance with FIGS. 10-11.
Rather, as shown in FIG. 17, the body 300 may be provided with a plurality of upper passages 302, and a plurality of lower passages 304, all communicating with a main conduit 306 in turn communicating with the head end 308 of a cylinder 310. In such system, the first and second members 36, 44 are brought together prior to the introduction of any elastomeric material on which tread i5 to be formed (~IG. 18), and then the cylinder 310 is actuated so that elastomeric material 312 is injected through the conduit 306, through the passages 302, 304 in the body 300, and onto the body 300, and into the cavity defined by the surfaces of the body 300 and the surfaces of the tread-forming shoes 50, 56, meanwhile with such elastomericmaterial having tread formed thereon during such operation.
The member 36 may be subsequently removed from the member 44 after insertion of the bolts 70, as shown in FIG. 19, whereupon elastomeric material 314, 316 remains on the shoes 56, and on the shoes 50, in accordance with the previous embodiment. Subsequent steps in this method are identical to those shown in FIGS. 13-15.
As yet another embodiment, the member 36' is provided with passages 350, 352 which communicate with conduits 354, 356 which in turn com~.unicate with a main conduit 358, communicating ~ith the head end 360 of a cylinder 362.
~0~ ~765 Likewise, the member 44' is provided with passages 364, 366 which communicate with conduits 368, 37Q which in turn communicate with a conduit 372 in turn communicating with the head end 374 of another cylinder 376. The cylinders 362, 376 are filled with elastomeric material 378 which is made to flow into the appropriate tread-forming areas, through the member 36' and member 44' with the members 36', 44' already brought together, and without the body 72, having had previously applied thereto any elastomeric 10 material.
In yet another method, it will be understood that a portion of the elastomeric material can be initially applied to the body 72, and the remaining necessary elastomeric material may be applied through the method in accordance with FIGS. 17-19 or the method in accordance with FIG. 20.
While both embodiments described include a centerparting mold apparatus, it is to be understood that the parting line of the mold portions need not be substantially at the center of the overall apparatus, but can be spaced therefrom, i.e., the mold apparatus could be of the edgeparting or shoulder-parting type.
Claims (17)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In a method of forming a tread on a green tire carcass in which uncured elastomer is first deposited onto a peripheral surface of an annular body, then trans-ferred to a pair of members by first moving the members into contact with the uncured elastomer on the annular body and then separating the members with the uncured elastomer adhering thereto from the annular body, and subsequently applied to a tread area of green tire carcass by moving the members to a position at which the uncured elastomer adhering thereto contacts the green tire carcass positioned between the members, the improvement comprising:
said step of transferring the uncured elastomer to the members includes the steps of moving a plurality of tread forming shoes mounted on the members from an out-ward extended position radially inwardly to an inward retracted position forming a tread on the uncured elastomer, and then moving the shoes and hence the uncured elastomer adhering thereto radially outwardly to an intermediate position between said inward retracted and outward extended position.
said step of transferring the uncured elastomer to the members includes the steps of moving a plurality of tread forming shoes mounted on the members from an out-ward extended position radially inwardly to an inward retracted position forming a tread on the uncured elastomer, and then moving the shoes and hence the uncured elastomer adhering thereto radially outwardly to an intermediate position between said inward retracted and outward extended position.
2. The method of claim 1 wherein said step of moving the shoes to said intermediate position includes the steps of resiliently urging the shoes from the inward retracted position toward the outward extended position and selectively limiting movement of said shoes to said inter-mediate position.
3. The method of claim 1 including the step of decreasing the adhesion between the uncured elastomer and the annular body subsequent to the step of moving the shoes into contact with the uncured elastomer.
4. The method of claim 3 wherein said step of decreasing the adhesion includes the step of supplying cooling liquid to the annular body.
5. The method of claim 1 including the step of forcing the uncured elastomer from the annular body sub-sequent to the step of moving the shoes into contact with the uncured elastomer.
6. The method of claim S wherein said step of forcing the uncured elastomer from the body includes the step of applying pressurized fluid between the uncured elastomer and the annular body.
7. In a method of forming a tread on a green tire carcass in which uncured elastomer is first injected into a pair of annular cavities individually formed be-tween an annular body and a pair of members for forming a tread pattern in the band of uncured elastomer in the cavities, then retained on the members upon moving the members away from the annular body, and subsequently applied to a tread area of a green tire carcass by moving the members to a position at which the uncured elastomer retained on the annular body is applied to the green tire carcass positioned between the members, the improvement comprising:
said step of retaining the uncured elastomer on the members includes the steps of moving a plurality of shoes mounted on the members, and hence the uncured elastomer adhering thereto, to an intermediate position between an inner retracted position and an outward extended position, and controllably increasing an inner diameter of the band of uncured elastomer adhering to the shoes.
said step of retaining the uncured elastomer on the members includes the steps of moving a plurality of shoes mounted on the members, and hence the uncured elastomer adhering thereto, to an intermediate position between an inner retracted position and an outward extended position, and controllably increasing an inner diameter of the band of uncured elastomer adhering to the shoes.
8. The method of claim 7 wherein the step of moving the shoes to said intermediate position includes resiliently urging the shoes from the inward retracted position toward said outward extended position and selec-tively limiting movement of said shoes to said intermediate position.
9. In an apparatus for forming a tread on a green tire carcass, said apparatus including an annular body onto which the uncured elastomer is first deposited, and first and second members movable between a first position at which the members are spaced apart sufficient for positioning the annular body therebetween and a second position at which the members substantially encompass the uncured elastomer on said annular body, each of said members having a plurality of shoes movable between an outward extended position at which the shoes are free from contact with the uncured elastomer on the annular body and an inward retracted position at which the shoes are in contact with the uncured elastomer, the improvement comprising:
means for moving the shoes to an intermediate position between said inward retracted and outward extended positions in response to the members being moved from the second position to the first position.
means for moving the shoes to an intermediate position between said inward retracted and outward extended positions in response to the members being moved from the second position to the first position.
10. The apparatus of claim 9 wherein said means includes resilient means for urging the shoes toward the outward extended position and means for selectively limiting movement of the shoes at said intermediate position.
11. The apparatus of claim 10 wherein the means for selectively limiting movement of the shoes includes a plurality of openings in the members, a recess positioned in each of the shoes and being in alignment with a respec-tive one of the openings in the members at the intermediate position of the shoes, and a plurality of elongated shafts slidably positioned within the openings in the members and selectively insertable into the mating recess in the adjacent shoe.
12. The apparatus of claim 9 including means for selectively decreasing the adhesion between the uncured elastomer and the annular body.
13. The apparatus of claim 12 wherein said means for selectively decreasing the adhesion includes passage means in said annular body and means for directing cooling liquid through said passage means.
14. The apparatus of claim 9 including means for forcing the uncured elastomer from the annular body upon movement of the shoes to said intermediate position.
15. The apparatus of claim 14 wherein said i forcing means includes a plurality of chambers in said annular body, a plurality of poppet valve members movably mounted in said chambers, said poppet valve members being movable between a retracted position at which communication between the chamber and the peripheral surface of the annular body portion is blocked and an extended position at which the chamber is in communication with the peripheral surface of the annular body, and means for introducing pressurized fluid into the chambers for moving the poppet valve members to their extended positions and directing pressurized fluid between said uncured elastomer and the annular body.
16. The apparatus of claim 9 wherein said annular body includes means for venting excess uncured elastomer from between the annular body and the shoes in response to movement of the shoes to the second position and means for automatically cutting the excess uncured elastomer from the uncured elastomer between the annular body and said shoes in response to movement of the shoes to the intermed-iate position.
17. The apparatus of claim 16 wherein said vent-ing means includes an annular depression in the annular body, a ring encircling the annular body, a passage in the ring communicating the annular depression with the outer periphery of the ring, said ring being movable between a first position at which said uncured elastomer can flow into the annular depression and a second position at which flow of uncured elastomer into the annular depression is blocked, said cutting means being said ring.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA360,059A CA1102977A (en) | 1976-07-19 | 1980-09-10 | Mold body for use in a method of forming a tread pattern on a tire |
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US70671276A | 1976-07-19 | 1976-07-19 | |
| US706,712 | 1976-07-19 | ||
| US05/791,660 US4152388A (en) | 1976-07-19 | 1977-04-28 | Tire tread forming method |
| US791,660 | 1985-10-28 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1094765A true CA1094765A (en) | 1981-02-03 |
Family
ID=27107741
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA282,459A Expired CA1094765A (en) | 1976-07-19 | 1977-07-11 | Tire tread forming method and apparatus |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS602979B2 (en) |
| CA (1) | CA1094765A (en) |
| FR (1) | FR2358975A1 (en) |
| GB (2) | GB1561223A (en) |
| IT (1) | IT1083900B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CH652642A5 (en) * | 1982-12-20 | 1985-11-29 | Milorad Milisavljevic | INSTALLATION FOR THE MANUFACTURE OF AGGLOMERATED, SINTERED, VULCANIZED OR PRESSED ARTICLES. |
| GB8301098D0 (en) * | 1983-01-15 | 1983-02-16 | Apsley Metals Ltd | Manufacture of elastomeric components |
| JP3853211B2 (en) | 2001-12-28 | 2006-12-06 | 株式会社ブリヂストン | Tire vulcanizing method and apparatus |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE512064A (en) * | 1951-06-21 | 1900-01-01 | ||
| FR1402373A (en) * | 1963-07-27 | 1965-06-11 | Pirelli | Method and device for molding a design in relief along the peripheral strip, in the plastic state, of one or more flexible rings juxtaposed and connected together and for providing the possible heat treatment of these rings |
| US3868203A (en) * | 1971-05-17 | 1975-02-25 | Nrm Corp | Tire molding machine |
| BE792783A (en) * | 1971-12-17 | 1973-03-30 | Pirelli | METHOD AND DEVICE FOR RELIEF MOLDING THE PERIMETRIC FACE OF TOROIDAL ARTICLES SUCH AS THE TREAD OF A PNEUMATIC BANDAGE |
| DE2502185C3 (en) * | 1975-01-21 | 1982-02-04 | Continental Gummi-Werke Ag, 3000 Hannover | Vulcanizing mold for pneumatic vehicle tires |
| DE2514973C3 (en) * | 1975-04-05 | 1978-06-08 | Sopecom S.A., Freiburg (Schweiz) | Injection molding device for manufacturing vehicle tires |
| US4022554A (en) * | 1975-04-16 | 1977-05-10 | Macmillan Mold Company | Retread molds |
-
1977
- 1977-06-28 GB GB4374278A patent/GB1561223A/en not_active Expired
- 1977-06-28 GB GB2693677A patent/GB1561224A/en not_active Expired
- 1977-07-07 JP JP52080508A patent/JPS602979B2/en not_active Expired
- 1977-07-08 FR FR7721109A patent/FR2358975A1/en active Granted
- 1977-07-11 CA CA282,459A patent/CA1094765A/en not_active Expired
- 1977-07-19 IT IT2588677A patent/IT1083900B/en active
Also Published As
| Publication number | Publication date |
|---|---|
| IT1083900B (en) | 1985-05-25 |
| GB1561224A (en) | 1980-02-13 |
| GB1561223A (en) | 1980-02-13 |
| FR2358975B1 (en) | 1982-08-13 |
| JPS602979B2 (en) | 1985-01-25 |
| FR2358975A1 (en) | 1978-02-17 |
| JPS5311979A (en) | 1978-02-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4181482A (en) | Tire tread forming apparatus | |
| US2497226A (en) | Method of making pneumatic tires | |
| KR0147182B1 (en) | Split mold apparatus for a tire vulcanizer | |
| CA2018685C (en) | Detachment of tires from molds | |
| US4100247A (en) | Method of manufacturing a disc wheel | |
| US5454894A (en) | Apparatus for producing tire with injection molded white sidewall | |
| CN101541518B (en) | Apparatus for vulcanization and moulding of vehicles tyres | |
| CA1094765A (en) | Tire tread forming method and apparatus | |
| EP2349700B1 (en) | Process and apparatus for moulding and vulcanisation of vehicle tyres | |
| US5152951A (en) | Vented tire mold and method for vacuum molding | |
| CA1315932C (en) | Compression mold for fiber-reinforced composite wheels | |
| US4181488A (en) | Tire tread forming mold body | |
| US4152388A (en) | Tire tread forming method | |
| CA2034540A1 (en) | Tire mold vent plug and method | |
| CA1102977A (en) | Mold body for use in a method of forming a tread pattern on a tire | |
| KR101281665B1 (en) | Method and apparatus for manufacturing tyres for vehicle wheels | |
| EP3731303B1 (en) | Battery cartridge for vehicle | |
| US20070009623A1 (en) | Annular venting of tire tread molds | |
| CA1061967A (en) | Casting or injection mold for vehicular tires | |
| US3768945A (en) | Injection molding apparatus providing a strippable flash for producing a plurality of flash-free articles | |
| EP0287495A2 (en) | Process and apparatus for injection molding tire treads | |
| CN111186052A (en) | Mold for producing rubber-free tire and using method thereof | |
| FI61829C (en) | FREQUENCY REQUIREMENT FOR FRAMING OF PNEUMATIC SHEET | |
| KR0160079B1 (en) | Envelope manufacturing apparatus of a recycling tyre | |
| CN212554639U (en) | Mold for producing rubber-free tire |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |