Apparatus for assembling a liner

Abstract

An apparatus for assembling a liner from a plurality of longitudinal sections of flexible material having longitudinal edges adapted to be joined one to another to form the liner includes a path means along which the longitudinal sections of flexible material can be conveyed in a laterally reduced condition, an assembly zone at which the longitudinal edges can be joined together to form the liner, and a guide structure about which the flexible material can turn upon exiting from the path means to provide an inner section and an outer section turned back with respect to the inner section. The guide structure presents a guide, surface over which the longitudinal sections of flexible material can pass, the surface being configured to facilitate spreading of each longitudinal section from the laterally reduced condition.

1 . A recovery head comprising:
 a chamber for receiving material to be recovered;   a screen associated with the chamber for screening material entering the chamber, said screen including a first side from material being screened passes therethrough, and a second side, with a plurality of elongate screen openings in the screen extending between the first and second sides thereof;   a plurality of tines mounted on support means disposed on the second side of the screen, each tine being moveable along a path at least part of which includes one of the elongate screen openings whereby the tine is receivable in and moveable along the elongate screen opening, the tine extending beyond the first side of the screen for at least part of the movement thereof along the screen opening; and   propulsion means for propelling the recovery head through a formation containing the material to be recovered, said propulsion means including an endless track having a first run which is exposed to the exterior of the recovery head for driving engagement with the environment through which the recovery head is to pass and a second run within the confines of the recovery head so as not to be exposed to that environment.   
     
     
         2 . A recovery head according to  claim 1  wherein the support means is adapted to move each tine through a cyclical path. 
     
     
         3 . A recovery head according to  claim 2  wherein the cyclical path takes the tines through at least part of the chamber for disturbing material received therein. 
     
     
         4 . A recovery head according to  claim 1  wherein the tine support means comprises a plurality of flights extending transversely of said path, each flight carrying a plurality of tines spaced along the length thereof at intervals corresponding to the spacing between the screen openings occupied by the tines, each tine being rigidly mounted on its respective flight, and two springs associated with each tine, each spring having a coiled portion and an arm portion, the coiled portion being fitted on and attached to the flight, and the arm portion of one spring extending to and engaging one of two adjacent flights, the arm portion of the other spring extending to and engaging the other of the two adjacent flights, whereby the springs interact with the two adjacent flights to bias the flight carrying the tine to assume an orientation in which the tine occupies a normal position extending through its respective screen opening as it travels therealong. 
     
     
         5 . A recovery head comprising:
 a chamber for receiving material to be recovered;   a screen associated with the chamber for screening material entering the chamber;   propulsion means for propelling the recovery head through a formation containing the material to be recovered, said propulsion means including an endless track having a first run which is exposed to the exterior of the recovery head for driving engagement with the environment through which the recovery head is to pass and a second run within the confines of the recovery head so as not to be exposed to that environment; and   a casing in which the chamber is accommodated, the casing having an interior through which the second run passes, the casing also having two openings through which the endless track passes between the interior of the casing and the exterior of the recovery head, and means associated with the openings for inhibiting ingress of unwanted material into the casing interior.   
     
     
         6 . A recovery head according to  claim 5  wherein said means associated with the opening comprise sealing means at each opening.