Actuator for movement of a tool and a tire carcass transfer device utilizing the actuator

A tire carcass transfer device (111) having a hollow housing (112) for receiving a tire carcass (160), a plurality of flexible cups (21) arranged in a circular band around the housing, vacuum means connected to the cups (21) and fluid powered actuators (10) for radial movement of the cups. The actuators (10) each have a return spring (24) therein to move piston (14) of the actuator (10) radially outwards by a predetermined amount on cessation of operation of the fluid powered actuator. Since all the pistons (14) are moved the same distance outwards by their respective springs (24), distortions to the carcass from its circular shape are minimized. An actuator (10) having a return spring (24) operating on a rod (15) operably connected to a piston (14) to return the actuator piston to a mid stroke position is also described.

BACKGROUND OF THE INVENTION 
The present invention relates to a tire carcass transfer device which 
includes a plurality of actuators operable for movement of flexible cups 
and also to an actuator operable for movement of a tool. The invention is 
particularly useful in relation to fluid powered actuators and more 
specifically to pneumatic actuators. 
A typical prior art transfer device has a cylindrical hollow housing and is 
moveable over a tire carcass building drum so as to enable the transfer 
device to pick up the cylindrical carcass. During the carcass pick up, the 
carcass may become distorted from its circular shape. The present 
invention seeks to reduce this carcass distortion. 
Furthermore, also disclosed in the present invention is an actuator 
operable for movement of a tool, and which on cessation of operation of 
the actuator will return a tool to a predetermined position which 
corresponds with a mid stroke position of the actuator. 
SUMMARY OF INVENTION 
According to the invention there is provided a tire carcass transfer device 
for transferring an uncured tire carcass from a carcass building machine 
to a tire building and forming machine and including: 
a hollow housing for receiving a substantially cylindrical tire carcass, 
a plurality of flexible cups disposed in at least one circular band about 
the housing, 
a means for evacuating air from said cups, 
and actuators connected one to each respective flexible cup, and operable 
to each have a radial stroke for radial movement of a respective cup, to 
enable said cups to contact the outer cylindrical surface of a carcass, 
said actuators each including a return spring effective to move the 
respective cup radially outwards by a predetermined distance which is less 
than the full radial stroke of the actuator, after cessation of operation 
of the actuators. 
The terms `radial` and `radially` refer to the radial direction relative to 
the cylindrical carcass. 
Also according to this invention there is provided an actuator operable for 
movement of a tool and which comprises, an actuator body, a piston having 
a reciprocating stroke within the actuator body, a rod operably connected 
with the piston and which is connectable with said tool, a first abutment 
associated with the rod and having a fixed axial position along the rod, a 
second abutment also associated with the rod and being axially 
displaceable along the rod, return spring means biasing the first and 
second abutments apart, and a third abutment having a fixed position and 
which is operably engageable by the first abutment after a predetermined 
movement of the piston along its stroke, so that continued movement of the 
piston along said stroke results in compression of the spring means so 
that on cessation of operation of the actuator, the spring returns the 
piston to a mid stroke position. 
The terms `axial` and `axially` refer to displacements along the 
longitudinal axis of the rod. 
The return spring can be housed within the rod, and the rod can pass 
through the actuator body and be fixed coaxially with the piston or 
alternatively the rod can be external of the actuator body and be 
connected to the piston by a yoke.

DETAILED DESCRIPTION OF INVENTION 
The actuators of FIG. 5 and FIG. 6 will first be described, and then the 
transfer device in which these actuators can be utilized. With reference 
now to FIG. 5, there is illustrated an actuator 10 according to this 
invention. The actuator is operated by pneumatic pressure and comprises an 
actuator body constituted by a pneumatic cylinder body 11 including a 
cylinder wall 20 and a pair of end walls 12 and 13 which together enclosed 
a bore 16. A piston 14 is reciprocable within the cylinder body 11 and is 
operated by air pressure acting on one side or the other of the piston. 
The piston 14 is fixed to a hollow rod 15 having a bore 19 therein and 
which is co-axial with the piston 14 and bore 16 and which extends on each 
side of the piston to pass sealingly through openings 17 and 18 in each 
end wall 12 and 13 respectively. The rod 15 is slideably supported by 
annular guide surfaces 37 and 38 within the openings 17 and 18 
respectively. The rod 15 has a tool, in this case a flexible cup 21, 
attached to its lower end by a securing bolt 22 which screws into the 
lower end of the bore 19. The upper end of the bore 19 is closed by a plug 
23. The terms `upper` and `lower` are used only with reference to FIG. 1 
and not intended to limit the relative positions in use. 
The flexible cup 21 is made of an elastomeric material, for example a 
polyurethane elastomer and has means for evacuation of air from inside the 
cup so that the cup can attach itself to, for example, the exterior on a 
tire carcass by means of the vacuum within the cup. 
A compression spring 24 is housed within the bore 19 of the rod 15. One end 
of the spring 24 reacts against a first abutment constituted by the plug 
23 and the other end reacts against a second abutment constituted by the 
head 25 of a strut 26. The spring 24 biases the plug 23 and the head 25 
apart. The strut 26 is arranged co-axially of the bore 19 and passes 
slidingly through the plug 23 and is anchored to a cap 27 which is axially 
separable from the end of the rod. 
The actuator body 11 is anchored to a support plate 28 and an auxiliary 
guide pin 29 which has one end fixed to the tool i.e. the flexible cup, 
and slides freely in an opening 30 in the support plate 28. The opening 30 
provides a guide surface 31, which is fixed in position relative to the 
body 11 so that the guide pin 29 has its longitudinal axis parallel with 
the axis of the bore 16 in which the piston 14 reciprocates. The guide pin 
29 has a longitudinal bore 32 therein which opens into the inside of the 
cup 21. A vacuum source (not shown) is attachable to the free end of the 
pin 29. 
The piston 14 is operable under air pressure on one side, or the other, of 
the piston to move between two extreme positions A and B in which it is in 
abutment with one of the end walls 12 or 13 respectively. With the piston 
14 positioned as illustrated in FIG. 5, if air pressure is applied to move 
the piston downwards, the cap 27 comes up against the end wall 12 which 
constitutes a third abutment. Since the cap 27 is connected to the head 25 
on the strut 26, the head 25 is now held in a fixed position relative to 
the end wall 12. Continued downwards movement of the piston 14 compresses 
the spring 24 between the head 25 and the plug 23. This continues until 
the piston 14 abuts the end wall 13 and the cup 21 is in the position 21 B 
shown in dotted lines. 
On release of the air pressure, the residual load in the spring 24 acting 
between the plug 23 and head 25 returns the piston upwards until the 
spring 24 is relaxed. The piston 16 is returned to a mid-stroke position 
dependant upon the free length of the spring 24. If air pressure is now 
applied to move the piston 14 upwards the piston will move until it abuts 
the end wall 12 and the cup 21 is in the position 21 A shown in dotted 
lines. The upward movement of the piston will cause the cap 27 to move 
with the rod 15 and separate from the end wall 12. 
With reference now to FIG. 6 there is illustrated another actuator 40 
comprising a second embodiment of the invention. Those components in FIG. 
2 which are similar to components in FIG. 1 have the same reference 
numerals. 
The actuator 40 comprises a pneumatic cylinder body 42 having a piston 
therein with an extension 41 thereof passing through the actuator body end 
wall 43. In this embodiment the flexible cup 21 is not attached, as in 
FIG. 1, directly onto a rod connected directly to the piston but is 
attached to a rod 44 which is external of the actuator body 42 and is 
connected to the piston by a bridge 46. The bridge 46 yokes together the 
pneumatic cylinder piston extension 41 and the rod 44. The cup 21 is fixed 
to one end of the rod 44 and sandwiches the bridge 46 between itself and 
the rod 44. The rod 44 also acts as a guide for movement of the flexible 
cup 21 and is guided for movement by a pair of bushes 51 and 52 in a 
surrounding sleeve 45 and is arranged so that its longitudinal axis is 
parallel with the axis of the piston in the actuator body 42. An adjusting 
sleeve 47 is arranged co-axially with the sleeve 45 and makes a screw 
threaded connection therewith so that the position of the sleeve 47 
relative to the sleeve 45 can be altered. The sleeve 47 is maintained in 
its adjusted position by a spring 48. The surrounding sleeve 45 and 
adjusting sleeve 47 together form a guide sleeve which has an adjustable 
length. 
The end portion of the rod 44 away from the cup 21 has a blind bore 55 
therein, the open end of which is closed by a plug 53 which is fastened to 
the rod 44. A compression spring 24 is housed in the bore 55 and has one 
end in abutment with the plug 53 and its other in abutment with the head 
25 of a strut 26, similarly to FIG. 5, The strut 26 is connected to an 
abutment disc 50 which can abut the end of the sleeve 47. 
Each pneumatic cylinder body 42 and rod 44 is held on a support plate 49 
and each cup 21 is connected via a central passageway 56 to a vacuum 
source which is connected to the cup 21 via a passageway 54 in the bridge 
46. 
The operation of the actuator is similar to that previously described. On a 
downward movement of the pneumatic cylinder piston, the cup 21 is moved 
downwards. This movement is guided by the rod 44 and the disc 50 comes 
into abutment with the sleeve 47 thereby holding the head 25 of the strut 
26 in a fixed position relative to the sleeve 47. Continued downward 
movement of the rod 44 causes compression of the spring 24 between the 
head 25 and the plug 53 until the plug 53 bottoms on the sleeve 45. On 
cessation of operation of the actuator, the spring 24 causes the rod 44 to 
move upwards, hence moving the cup 21 upwards and returning the pneumatic 
cylinder piston to a mid stroke position. The amount of upward movement of 
the guide pin 44 and the cup 21 can be adjusted by altering the relative 
positions of the sleeves 47 on the sleeve 45. 
Now with reference to FIG. 1 and FIG. 2, there is illustrated a tire 
carcass transfer device 111 also according to this invention and in which 
the above actuators are incorporated. 
The transfer device 111 comprises a hollow circular housing 112 for 
receiving a cylindrical tire carcass. The housing 112 has eight 
equiangularly spaced support plates 28 (for convenience only 3 of the 
plates are shown in FIG. 4) fixed thereon which extend axially on one side 
only of the housing 112. For the purposes of the description of the 
housing 112 the terms `axial` and `axially` refer to the longitudinal axis 
of the cylindrical housing and the term `circumferentially` refers to the 
circumference of the circular housing. If it is desired to transfer a tire 
carcass using only a single circular band of actuators and cups 21, then 
the actuators 10 of FIG. 5 are the preferred embodiments since this 
actuator is particularly useful for supporting very large cups. The 
axially outer end portions of the support plates 28, each support an 
actuator 10, as illustrated in FIG. 5 so that a plurality of said 
actuators 10 is arranged in a circular band. 
The housing 112 has a mounting bracket 118 whereby it can be slideably 
mounted onto a base for movement between a tire carcass building station 
and a tire building and forming station. 
Whilst the housing is described as providing support for actuators 10 as 
described with reference to FIG. 5, if the transfer band comprises a 
plurality of circular bands of cups 21 then the actuators 40 of the type 
shown in FIG. 6 can also be utilized. The actuators 10 are each fitted 
with an oval flexible cup 21 from which air can be evacuated and are 
disposed in a circular band comprising eight actuators 10 and flexible 
cups 21. 
Whilst in the present embodiment the circular band of cups 21 on the 
housing 112, comprises eight actuators and cups, it is envisaged that the 
number of actuators and their respective cups could be altered. 
Furthermore it is envisaged that a transfer device could comprise a 
plurality of circular bands of suction cups. 
With reference now to FIG. 3 and FIG. 4 there is illustrated the transfer 
device 111 in use, for conveying a substantially cylindrical uncured tire 
carcass 160 (sometimes called a carcass band) from a carcass building 
machine 151 to a tire tire building and forming machine 152. The transfer 
device 111 is arranged co-axially with both the carcass building drum 153 
on machine 151 and a tire forming drum 154 on machine 152, and is 
slideably mounted by its bracket 118 on a base 115 extending between the 
two machines 151 and 152. 
A cylindrical tire carcass band 160 is built up on the carcass building 
drum 153. The transfer device 111 moves over the carcass band 160 until it 
is concentric with and axially located at the mid portion of the carcass. 
The flexible cups 21 are moved by their respective actuators 10 radially 
inwards to contact the carcass band 160 and air is evacuated from the cups 
21 so that they attach themselves to the outer surface of the carcass band 
160. The carcass band 160 is released from the drum 153 by, for example, 
blowing air through the drum. The air pressure supply to the pneumatic 
cylinder 11 of the actuators 10 is then cut off and the return springs 24 
in each actuator then all move the suction cups 21 radially outwardly by 
the same predetermined amount, so that the carcass is not distorted from 
its circular shape when lifting the carcass clear of the drum 153. The 
carcass has sufficient strength to remain in the circular shape during the 
subsequent transfer. The carcass is then held in that position by the 
springs 24 and the transfer device 111 then moves from the carcass 
building drum 153 to the tire building drum 154 with the tire carcass band 
160 held in a cyclindrical configuration by the cups 21. The transfer 
apparatus 111 passes over the tire building drum 154 so that the carcass 
is co-axial with the tire building drum. 
The tire building drum 154 expands to make contact with the carcass, and 
the vacuum to the cups 21 is cut-off. The cups 21 are then moved by their 
respective actuator 10 radially outwards to their outermost positions. The 
transfer apparatus can now be moved from the tire building drum leaving 
the carcass band thereon. 
While the invention has been described with reference to the specific 
examples illustrated, it is to be understood that minor changes could be 
made without departing from the spirit and scope of the invention.