GB1589101A

GB1589101A - Heating press for tyre retreading

Info

Publication number: GB1589101A
Application number: GB4187/78A
Authority: GB
Original assignee: Peters and Co Inc
Current assignee: Peters and Co Inc
Priority date: 1977-03-15
Filing date: 1978-02-02
Publication date: 1981-05-07
Also published as: IT7820279A0; IT1092738B; DE2711118A1

Description

(54) HEATING PRESS FOR TYRE RETREADING (71) We, PÈNRS & CO., of 2-8 Sand äckerstrasse, 8502 Zirndorf tiber Niirnberg.

Federal Republic of Germany, a offene Handelsgesellschaft organised under the laws of the Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a heating press for the retreading of vehicle tyres.

Heating presses of this kind and their use for the vulcanising in place of prefabricated tread strips are described in German (Fed.

Rep.) Published Specification No.

23 53 747.5. Heating presses for the retreading of tyres are also described in German (Fed. Rep.) Patent Specification No.

1220119.

Whereas during normal retreading a tyre can be slightly reduced in diameter by splaying and so be inserted in a mould box, the introduction of a tyre with a laidon, pre-vulcanised tread strip presents certain difficulties, because the laid-on tread strip in some circumstances does not deform in the same manner as the tyre through the reduction of the tyre diameter, with the result that the tread strip together with its adhesive layer detaches from the tyre surface.

Difficulties are also met with when not only the treads must be renewed, but also new belt layers of, for example, steel fabric must be applied with the tread. Furthermore, additional operating steps, which are to be avoided if possible, result from the splaying.

According to the present invention there is provided a heating press for the retreading of vehicle tyres, comprising two relatively movable elements co-operable to define a space therebetween for reception of a tyre bearing a tread stripl to be vulcanised thereto, one of the elements being provided with a cylindrical hub portion to suport such tyre at the inner circumference thereof, and mould means locatable between the elements and comprising an annular heatable mould box, which is adapted to enclose the tyre at the outer circumference thereof and which is provided with an annular first support member arranged to extend beyond the shoulder of the tyre at one side thereof, and an annular second support member associated with one of the elements and arranged to extend beyond the shoulder of the tyre at the other side thereof.

With a heating press of the described kind, retreads pf rubber to be ivulcanised out and renewals of the tread from prefabricated tread strips can be performed. In both cases it is possible, due to the relatively long lateral support members, which enclose the tyre, to also renew the tyre shoulders and the sidewalls by insertion of unvulcanised rubber. Due to the separation of the second suport member from the mould :box, the tyre can be inserted in the press ana the mould box pushed over the inserted tyre so that the otherwise necessary splaying of the tyre for insertion in the mould box is redundant, whereby an additional operating step is saved.

An embodiment of the present invention will now be more particularly described by way of example with reference to the accompanying drawing, which is a schematic cross-section of the upper half of a heating press according to said embodiment.

Referring now to the drawing, there is shown the upper half of a heating press comprising a preferably rigidly arranged cover part 1, which carries a hollow guide cylinder 2 acting in the manner of a wheel rim to support a tyre 9, and a locally movable cover part 3 connected with the cover part 1 by way of a central tightening element 4. A mould box 5, which is equipped with heating chambers 6, is shown inserted between the cover parts. The mould box receives an inflatable pressure body 8 in a groove-shaped recess 7. The tyre 9, with a laid-on, pre-vulcanised tread strip 10 and interposed vulcanisable connecting layer 11, is inserted in the mould box 5 and together with the mould box is pushed onto the cylinder 2.For laterally supporting the tyre 9, there is provided a first limb 12 protruding beyond the shoulder of the tyre and constructed to be integral with the mould box 5, and a second limb 13 constructed as a profiled ring and connected by screws 14 with the cover part 1.

The entire arrangement forms a symmetrical body around the axis of the tightening element 4, while the cover part 3 and the mould box 5 can be equipped with rollers for easier mobility.

During the closing of the press, the mould box 5 is driven towards the cover part 1 until the limb 13 bears closely against the tyre 9 and engages one shoulder thereof. Thereupon, the cover part 3 is driven towards the cover part 1 so that the mould box together with the cover padts forms a closed, pressure-tight vulcanising mould.

The heating press is held together by the tightening element 4 through a spindle (not shown).

Pressure is now applied to the tyre and the pressure body 8 by way of, respectively, a valve 15 and a valve 16 so that the tread strip 10 is pressed firmly against the tyre 9.

In this setting, the layer 11 and additional rubber possibly laid on for the renewal of the tyre shoulders and sidewalls are now fully heated. As a result, all parts are undetachably connected with the tyre.

Press plates 17 and 18 of the cover parts 1 and 2 are provided with heating equipment, for example heating chambers 21, for full heating of the lateral regions of the tyre.

Since gases can issue during the vulcanising of the layer 11, ventilation open ings 19 are provided in the limbs 12 and 13 and in the press plates 17 and 18 of the cover parts 1 and 2.

Since tyres of different diameters and, in some cases tyres of different shapes in the region of the tyre shoulders are to be treated in the heating press, the limb 13 is detachably connected to the cover part 1 so that similar limbs of different diameters and contours can be used. Of course, these limbs 13 must in each case be constructed and arranged to correspond with the particular diameter and contour of the limb 12 of the mould box 5.

In the place of the mould box 5 with inserted pressure body 8, a mould box with a machined profile can be used for retreading with the use of vulcanisible rubber.

WHAT WE CLAIM IS:- 1. A heating press for the retreading of vehicle tyres, comprising two relatively movable elements co-operable to define a space therebetween for reception of a tyre bearing a tread strip to Ibe vulcanised thereto, one of the elements being provided with a cylindrical hub portion to support such tyre at the inner circumference thereof, and mould means locatable between the elements and comprising an annular heatable mould box, which is adapted to enclose the tyre at the outer circumference thereof and which is provided with an annular first support member arranged to extend beyond the shoulder of the tyre at one side thereof, and. an annular second support member associated with one of the elements and arranged to extend beyond the shoulder of the tyre at the other side thereof.

2. A heating press as claimed in claim 1, wherein the two elements are arranged to extend in, respectively, two substantially parallel and vertical planes.

3. A heating press as claimed in either claim 1 or claim 2, comprising connection means to interconnect the two elements centrally thereof, the connection means being operable to adjust the relative position of the elements.

4. A heating press as claimed in any one of the preceding claims, wherein each of the support members has a contoured portion locatable against the tyre.

5. A heating press as claimed in any one of the preceding claims, wherein the mould box is co-operable with the second support member at a location level with or outwardly of the outer circumference of the tyre with the tread strip thereon.

6. A heating press as claimed in any one of the preceding claims, wherein the second support member and the element associated therewith are provided with ventilation openings.

7. A heating press as claimed in any one of the preceding claims, wherein the mould box is provided with a channel for the reception of an elastic inflatable pressure body.

8. A heating press as claimed in any one of the preceding claims, wherein the second support member is detachably mounted on the associated one of the elements to be exchangeable with other such support members of different diameters, said element being provided with means for individual detachable connection thereto of such support members.

9. A heating press for the retreading of vehicle tyres, substantially as hereinbefore described with reference to the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

9, there is provided a first limb 12 protruding beyond the shoulder of the tyre and constructed to be integral with the mould box 5, and a second limb 13 constructed as a profiled ring and connected by screws 14 with the cover part 1.

The entire arrangement forms a symmetrical body around the axis of the tightening element 4, while the cover part 3 and the mould box 5 can be equipped with rollers for easier mobility.

During the closing of the press, the mould box 5 is driven towards the cover part 1 until the limb 13 bears closely against the tyre 9 and engages one shoulder thereof. Thereupon, the cover part 3 is driven towards the cover part 1 so that the mould box together with the cover padts forms a closed, pressure-tight vulcanising mould.

The heating press is held together by the tightening element 4 through a spindle (not shown).

Pressure is now applied to the tyre and the pressure body 8 by way of, respectively, a valve 15 and a valve 16 so that the tread strip 10 is pressed firmly against the tyre 9.

In this setting, the layer 11 and additional rubber possibly laid on for the renewal of the tyre shoulders and sidewalls are now fully heated. As a result, all parts are undetachably connected with the tyre.

Press plates 17 and 18 of the cover parts 1 and 2 are provided with heating equipment, for example heating chambers 21, for full heating of the lateral regions of the tyre.

Since gases can issue during the vulcanising of the layer 11, ventilation open ings 19 are provided in the limbs 12 and 13 and in the press plates 17 and 18 of the cover parts 1 and 2.

Since tyres of different diameters and, in some cases tyres of different shapes in the region of the tyre shoulders are to be treated in the heating press, the limb 13 is detachably connected to the cover part 1 so that similar limbs of different diameters and contours can be used. Of course, these limbs 13 must in each case be constructed and arranged to correspond with the particular diameter and contour of the limb 12 of the mould box 5.

In the place of the mould box 5 with inserted pressure body 8, a mould box with a machined profile can be used for retreading with the use of vulcanisible rubber.

WHAT WE CLAIM IS:-

1. A heating press for the retreading of vehicle tyres, comprising two relatively movable elements co-operable to define a space therebetween for reception of a tyre bearing a tread strip to Ibe vulcanised thereto, one of the elements being provided with a cylindrical hub portion to support such tyre at the inner circumference thereof, and mould means locatable between the elements and comprising an annular heatable mould box, which is adapted to enclose the tyre at the outer circumference thereof and which is provided with an annular first support member arranged to extend beyond the shoulder of the tyre at one side thereof, and. an annular second support member associated with one of the elements and arranged to extend beyond the shoulder of the tyre at the other side thereof.

2. A heating press as claimed in claim 1, wherein the two elements are arranged to extend in, respectively, two substantially parallel and vertical planes.

3. A heating press as claimed in either claim 1 or claim 2, comprising connection means to interconnect the two elements centrally thereof, the connection means being operable to adjust the relative position of the elements.

4. A heating press as claimed in any one of the preceding claims, wherein each of the support members has a contoured portion locatable against the tyre.

5. A heating press as claimed in any one of the preceding claims, wherein the mould box is co-operable with the second support member at a location level with or outwardly of the outer circumference of the tyre with the tread strip thereon.

6. A heating press as claimed in any one of the preceding claims, wherein the second support member and the element associated therewith are provided with ventilation openings.

7. A heating press as claimed in any one of the preceding claims, wherein the mould box is provided with a channel for the reception of an elastic inflatable pressure body.

8. A heating press as claimed in any one of the preceding claims, wherein the second support member is detachably mounted on the associated one of the elements to be exchangeable with other such support members of different diameters, said element being provided with means for individual detachable connection thereto of such support members.

9. A heating press for the retreading of vehicle tyres, substantially as hereinbefore described with reference to the accompanying drawing.