GB2092100A

GB2092100A - A transfer mechanism

Info

Publication number: GB2092100A
Application number: GB8200461A
Authority: GB
Original assignee: Vmi Epe Holland BV
Current assignee: Vmi Epe Holland BV
Priority date: 1981-01-29
Filing date: 1982-01-07
Publication date: 1982-08-11
Also published as: DE3202575A1; DE3202575C2; NL8100425A; JPS57146644A; GB2092100B

Abstract

A mechanism for transferring an annular body, for instance a ring like belt and tread assembly for a pneumatic tire, provided with a displaceable annular support member 6 on which radially operating piston- and cylinder assemblies 9 are arranged, each piston- and cylinder assembly being provided with a radially reciprocable piston rod 10 having attached thereto an engaging member 11 for engaging the body. A locking device serves to lock the piston rod in the radical position wherein the engaging member engages the body to be transferred. <IMAGE>

Description

SPECIFICATION A transfer mechanism The present invention relates to a mechanism for transferring an annular body, for instance a ring like belt and tread assembly for a pneumatic tire, provided with a displaceable annular support member onto which radially operating piston- and cylinder assemblies are arranged, each piston- and cylinder assembly being provided with a radially reciprocable piston rod having attached thereto an engaging member for engaging the body.

More in particular the present invention relates to a transfer mechanism which can be used in a tire building machine comprising a building device with a building drum to build belts and a tread so as to form an annular unit on the building drum, and also comprising a carcass device with a carcass drum so as to build a carcass, wherein the transfer mechanism serves to transfer the belt and tread assembly onto the carcass.

In order to be able to make pneumatic tires with different sizes, like different diameters, on one and the same tire building machine, the transfer mechanism should also be adjustable for various diameters for the built assembly of belts and tread. For that purpose the transfer mechanism is provided with an annular support and each piston- and cylinder assembly is provided with a reciprocable piston, having an engaging member attached thereto. On the building drum which forms a part of the building device, belts and a tread are built to form an annular body, and subsequently the annular support member of the transfer mechanism is arranged concentrically around said annular body and then, by means of the piston- and cylinder assemblies, the engaging members are moved against the annular body.Subsequently the diameter of the building drum is reduced so that the annular body is free from said drum, but clamped between the engaging members. By then displacing the transfer mechanism, the annular body is transferred onto the carcass so as to produce a pneumatic tire.

By using radially reciprocable engaging members, said engaging members are adjustable so as to engage the belt and tread assembly despite its diameter. Moreover because of the variable position of the engaging members, also differences in thickness of the annular body, caused by inaccuracies in the belts and tread, are balanced, so that the transfer mechanism is selfcentering and is capable to convey an annular body along a path in line with the center line of the building drum, on which the annular body was built.

The principal object of the invention is to maintain said self-centering action of the engaging members after the annular assembly of the belts and tread is moved from the building drum and consequently clamped between the engaging members of the transfer mechanism.

This is possible according to the invention because each piston- and cylinder assembly is provided with a locking device to lock the piston rod in the radial position wherein the engaging member engages the body to be transferred.

In a first embodiment variation of this invented transfer mechanism the locking device may consist of a housing with a bore through which the piston rod extends, a disc being pivotally supported in the housing, a passage extending eccentrically through said disc and the piston rod extending through the passage, said disc being pivotable between a first position in which the centerlines of the piston rod and the passage through the disc coincide and a second position in which the centerlines of the piston rod and the passage in the disc do not coincide so that then the disc forces the piston rod against the wall of the bore through the housing. In the first mentioned position the piston rod is freely reciprocable so as to move the engaging member to and from the annular body of belts and tread, and in the second position the piston rod is locked.

According to a second embodiment variation of the invented transfer mechanism each locking device consists of a substantially U-shaped clip, enveloping the piston rod and means for pulling the legs of said clip towards each other to thereby clamp the piston rod in the clip and consequently lock the piston rod against reciprocal movement.

A third embodiment variant of the invented transfer mechanism is characterized in that each locking device consists of a locking member which is reciprocable transversely to the piston rod, said locking member in its retracted position being free from the piston rod and in its extended position pushing against the piston rod so as to lock same.

In the above mentioned embodiment variations a drive cylinder may be provided to change the position of the disc, the clip or the locking member respectively.

The invention will be further elucidated in the following description of embodiments as illustrated in the drawing.

Figure 1 is a schematic side view of a tire building machine with the invented transfer mechanism.

Figure 2 is a schematic front view of the invented transfer mechanism.

Figure 3 is a radial section through a part of the transfer mechanism, and taken on the line Ill-Ill in figure 2.

Figure 4 is a section through an embodiment of a locking device for use in a transfer mechanism according to figure 2 and 3.

Figure 5 is a section through another embodiment of a locking device for use in the transfer mechanism according to figure 2 and 3.

Figure 6 is a section through still another embodiment of a locking device for use in the transfer mechanism according to figure 2 and 3.

The tire building machine according to figure 1 is provided with a building device 1, known per se, with a building drum 2 on which belts and a tread are composed to form an annular assembly.

Furthermore the tire building machine according to figure 1 is provided with a carcass device 3, known per se, with a carcass drum 4 on which the carcass for a pneumatic tire is built. Moreover a transfer mechanism 5 is present for receiving at the building drum 2 the annular assembly of belts and tread and to transfer this assembly to the carcass drum 4 to arrange the annular assembly around the carcass, built on the carcass drum 4.

The transfer mechanism is further illustrated in figure 2 and is provided with an annular support member 6 which is slidably supported, by means of a foot 7, on rails 8 between the building device 1 and the carcass device 3 according to figure 1. On the annular support member 6 a number of, for instance six, piston- and cylinder assemblies are radially arranged, which assemblies being powered by for instance pressurized air to extend and withdraw a piston rod 10 secured to each piston. According to figure 3 an engaging member 11 is secured on the piston rod 10 of each piston- and cylinder assembly 9. To each engaging member two guide bars 12 are mounted, said guide bars being radially slidably supported in the annular support member 6 via guide bearings 13.

After in the building device 1 on the building drum 2 belts and a tread are composed to form an annular body, the transfer mechanism 5 is displaced over the rails 8 to a position in which the annular support member 6 is arranged concentrically around the building drum 2 and the annular body arranged thereon. Then by means of the piston- and cylinder assemblies the engaging members 11 are pushed against the tread of the annular body on the building drum 2 and the piston rods of the cylinder assemblies are subsequently locked.Next the building drum 2 is freed from the belt and tread assembly because the building drum, which is known per se, comprises segments which, from a position in which they form a drum surface with a larger diameter, are radially retractable inwards to a position in which the segments are free from the belts which were composed on the building drum 2 then the segments were in the larger diameter positions.

Since the engaging members 11 are radially reciprocable by the piston- and cylinder assemblies 9, the same engaging members can be used to engage annular bodies with different diameters. Consequently one and the same transfer mechanism can be used for transferring pneumatic tires with different diameters.

Moreover local irregularities in thickness of the belts and the tread can be taken care of, because the radial position of each engaging member 11 is determined by the local position of the tread of the annular body on the building drum 2.

The main object of the invention is to lock the engaging members 11 in the position in which they engage the tread of the annular body on the building drum 2. For this purpose a locking device 14 for each piston rod 10 is present, as seen in figure 3. Various constructions for the locking device can be used. An example of such a locking device is illustrated in figure 4, wherein through a housing 1 5 the piston rod 10 of one of the pistonand cylinder assemblies 9 extends. In the housing a circular disc 1 6 is arranged rotatably, and a passage extends eccentrically through the disc whereas the piston rod protrudes through said passage.In the position according to figure 4 the longitudinal central axis of the piston rod 10 and the longitudinal central axis of the passage through the disc 1 6 coincide, so that the piston rod can freely reciprocate through the passage in disc to move the engaging member 11, secured to the piston rod, towards the tread of the annular body consisting of belts and treads.By means of an auxiliary piston 1 8 in an auxiliary cylinder 23 and via a coupling bar 17, the disc 1 6 is pivotable into a position in which the longitudinal central axis of the passage through the disc is eccentrical relative to the longitudinal central axis of the piston rod 10, so that the piston rod is forced against the wall of the bore through the housing 1 5, so that the piston rod 10 is no longer reciprocable and consequently is locked.

Another possible construction of the locking device 14 is illustrated in figure 5, in which the piston rod 10 of one of the piston- and cylinder assemblies 9 extends reciprocably through a substantially U-shaped clip 1 9. By means of an auxiliary cylinder 20 the free ends of the clip 1 9 can be pulled towards each other so that the piston rod 10 is clamped in the clip 19 and is locked then.

Still another possible construction of the locking device is indicated in figure 6, in which the piston rod 10 of the piston- and cylinder assemblies 9 extends reciprocably between the teeth of a fork 21. By forcing the fork against the piston rod 10 by means of an auxiliary drive cylinder 22, the piston rod 10 is clamped against reciprocation and consequently it is locked.

By locking the piston rods 10 of the piston- and cylinder assemblies 9 by means of the locking devices 14, the engaging members 11 are kept in their positions in which they clamp between them the annular body, consisting of belts and tread, in its configuration as obtained on the building drum 2. Here the positions of the engaging members 11 are determined by the diameter and the shape of the annular body so that bodies with various diameters can be clamped and irregularities in the thickness of the annular body can be taken care of by the different positions of the various engaging members 11 of the various locked piston rods 1 0. Thus the positioning of the engaging members 11 against the annular body is self centering relative to the longitudinal central axis of the building drum 2 since the annular body is assembled on said building drum. The transfer mechanism 5 is thus capable to clamp an annular body with any diameter and to transfer it from the building drum 2 to the carcass drum 4 along a path which is in line with the longitudinal central axis of the building drum.

Claims

1. A mechanism for transferring an annular body, for instance a ring like belt and tread assembly for a pneumatic tire provided with a displaceable annular support member on which radially operating piston- and cylinder assemblies are arranged, each piston- and cylinder assembly being provided with a radially reciprocable piston rod having attached thereto an engaging member for engaging the body, characterized in that each piston- and cylinder assembly is provided with a locking device to lock the piston rod in the radial position wherein the engaging member engages the body to be transferred.

2. A transfer mechanism according to claim 1, characterized in that each locking device consists of a housing with a bore through which the piston rod extends, a disc being pivotally supported in the housing, a passage extending eccentrically through said disc and the piston rod extending through the passage, said disc being pivotable between a first position in which the center-lines of the piston rod and the passage through the disc coincide and a second position in which the centerlines of the piston rod and the passage in the disc do not coincide so that then the disc forces the piston rod against the wall of the bore through the housing.

3. A transfer mechanism according to claim 2, characterized by a drive cylinder for rotating the disc between said first position and said second position, and reverse.

4. A transfer mechanism according to claim 1, characterized in that each locking device consists of a substantially U-shaped clip enveloping the piston rod and means for pulling the legs of said clip towards each other to thereby clamp the piston rod in the clip and consequently lock the piston rod against reciprocal movement.

5. A transfer mechanism according to claim 4, characterized by a drive cylinder to pull the legs of the U-shaped clip towards each other.

6. A transfer mechanism according to claim 1, characterized in that each locking device consists of a locking member which is reciprocable transversely to the piston rod, said locking member in its retracted position being free from the piston rod and in its extended position pushing against the piston rod so as to lock same.

7. A transfer mechanism according to claim 6, characterized by a drive cylinder to reciprocate the locking member.

8. A transfer mechanism constructed and arranged substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.