We claim:
1. A conveyor chain link for forming an oven and proofing chain which can be pulled through a substantially closed guide track, said link comprising:
a block link;
at least one longitudinal plate, said plate having one end pivotally fixed to said block link and a second end pivotally linkable to a block link of an adjacent conveyor chain link;
at least one horizontal roller fixed to said at least one longitudinal plate for guiding said link in the track; and
at least one vertical roller detachably fixed to said block link for supporting said link in the track.
2. The conveyor chain link as in claim 1, in which said vertical roller includes a stud extending from one side of said roller coaxial with an axis of rotation of said roller, and said stud is received in a bore formed in said block link to detachably fix said roller to said block link.
3. The conveyor chain link as in claim 1, including a sweeper extending from said at least one plate, wherein said sweeper urges debris along the track as said link passes through the track.
4. The conveyor chain link as in claim 3, in which said sweeper s formed from a material selected from a group consisting of plastic and metal.
5. The conveyor chain link as in claim 3, in which said sweeper is slidable relative to at least a portion of said at least one longitudinal plate.
6. The conveyor chain link as in claim 3, in which a stop plate fixed relative to said at least one longitudinal plate is engageable with said sweeper to square said sweeper relative to the track.
7. The conveyor chain link as in claim 1, including a second longitudinal plate extending substantially parallel to said at least one longitudinal plate, and said at least one horizontal roller is interposed between said second longitudinal plate and said at least one longitudinal plate.
8. The conveyor chain link as in claim 1, including a second vertical roller detachably fixed to said block link, which said block link includes opposing sides, and said at least one vertical roller is detachably fixed to one of said sides and said second vertical roller is detachably fixed to another of said sides.
9. A conveyor chain link for forming an oven and proofing chain which can be pulled through a substantially closed guide track, said link comprising:
a block link;
a least one longitudinal plate, said plate having one end pivotally fixed to said block link and a second end pivotally linkable to a block link of an adjacent conveyor chain link;
at least one vertical roller fixed to said block link for supporting said link in the track; and
a sweeper fixed relative to said at least one longitudinal plate for engaging debris in a track as the link passes through the track.
10. The conveyor chain link as in claim 9, in which said vertical roller is detachably fixed to said block link.
11. The conveyor chain link as in claim 10, in which said vertical roller includes a stud extending from one side of said roller coaxial with an axis of rotation of said roller, and said stud is received in a bore formed in said block link to detachably fix said roller to said block link.
12. The conveyor chain link as in claim 10, including a second vertical roller detachably fixed to said block link, wherein said block link includes opposing sides, and said at least one vertical roller is fixed to one of said sides and said second vertical roller is detachably fixed to another of said sides.
13. The conveyor chain link as in claim 9, in which said sweeper s formed from a material selected from a group consisting of plastic and metal.
14. The conveyor chain link as in claim 9, in which said sweeper is sweeper is slidable relative to at least a portion of said at least one longitudinal plate.
15. The conveyor chain link as in claim 9, in which a stop plate fixed relative to said at least one longitudinal plate is engageable with said sweeper to square said sweeper relative to the track.
16. The conveyor chain link as in claim 9, in which at least one horizontal roller is fixed to said at least one longitudinal plate for guiding said link in a track.
17. The conveyor chain link as in claim 16, including a second longitudinal plate extending substantially parallel to said at least one longitudinal plate, and said at least one horizontal roller is interposed between said second longitudinal plate and said at least one longitudinal plate.
18. A conveyor chain link for forming an oven and proofing chain which can be pulled through a substantially closed guide track, said link comprising:
a block link;
a least one longitudinal plate, said plate having one end pivotally fixed to said block link and a second end pivotally linkable to a block link of an adjacent conveyor chain link;
at least one horizontal roller fixed to said at least one longitudinal plate for guiding said link in the track;
at least one vertical roller detachably fixed to said block link for supporting said link in the track, wherein said vertical roller includes a stud extending from one side of said roller coaxial with an axis of rotation of said roller, and said stud is received in a bore formed in said block link to detachably fix said roller to said block link; and
a sweeper fixed relative to said at least one longitudinal plate for engaging debris in a track as the link passes through the track.
19. The conveyor chain link as in claim 18, including a second vertical roller detachably fixed to said block link, wherein said block link includes opposing sides, and said at least one vertical roller is fixed to one of said sides and said second vertical roller is detachably fixed to another of said sides.
20. The conveyor chain link as in claim 18, in which said sweeper s formed from a material selected from a group consisting of plastic and metal.
21. The conveyor chain link as in claim 19, including a second longitudinal plate extending substantially parallel to said at least one longitudinal plate, and said at least one horizontal roller is interposed between said second longitudinal plate and said at least one longitudinal plate.
22. he conveyor chain link as in claim 19, in which said sweeper is sweeper is slidable relative to at least a portion of said at least one longitudinal plate.
23. The conveyor chain link as in claim 19, in which a stop plate fixed relative to said at least one longitudinal plate is engageable with said sweeper to square said sweeper relative to the track.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
We claim:
1. A pipeline pig for a pipeline having an inner wall, the pig comprising a central body member, a first drive member mounted on the body member, the first drive member including a central annular support element mounted on, to surround, the body member, and a plurality of circumferentially spaced primary drive elements each having a one end and a free end, the one end of each of which is secured to the support element whereby the primary drive elements extend substantially radially from the support element and such that, in use, the free ends of the primary drive elements engage the inner wall of the associated pipeline, each primary drive element being capable of bending rearwardly of the direction of movement of the pig about the one end extent thereof to maintain engagement with the inner wall of pipelines within a range of diameters without increasing the drag thereon, the first drive member further including a flexible backing disc rearward of the primary drive elements and adapted to seal against the inner wall of the pipeline for all bent positions of the primary drive elements.
2. A pipeline pig as claimed in claim 1 in which the rear surface of the one end extent of each primary drive element is recessed to provide a pivotal region of reduced thickness about which the primary drive element can bend.
3. A pipeline pig as claimed in claim 1 in which at least one support wire extends between each primary drive element and the body member, the wires being so arranged as to prevent return movement of the primary drive elements from their bent positions within a pipeline engaging the inner wall thereof when subjected to fluid pressures within the pipeline.
4. A pipeline pig as claimed in claim 1 in which the first drive member further includes, between the primary drive elements and the backing disc, a plurality of circumferentially spaced secondary drive elements one end of each of which is secured to the support element whereby the secondary drive elements extend substantially radially from the support element, each secondary drive element underlying the space between two adjacent primary drive elements whereby the primary and secondary drive elements combine to present a continuous front surface area to the first drive member.
5. A pipeline pig as claimed in claim 4 in which adjacent primary drive elements are interconnected by a retaining strap to prevent circumferential separation thereof.
6. A pipeline pig as claimed in claim 5 in which the retaining strap is also secured to the secondary drive element underlying the adjacent primary drive elements.
7. A pipeline pig as claimed in claim 1 in which the first drive member is mounted on a front carrier member itself mounted in the hollow front extent of the body member to be slidable therein.
8. A pipeline pig as claimed in claim 1 and further comprising a second drive member secured to the rear extent of the body member, the second drive member including a central annular support element mounted on, to surround, the body member, and a plurality of circumferentially spaced primary drive elements each having a one end and a free end, the one end of each of which is secured to the support element whereby the primary drive elements extend substantially radially from the support element and such that, in use, the free ends of the primary drive elements engage the inner wall of the associated pipeline, each primary drive element being capable of bending rearwardly of the direction of movement of the pig about the one end extent thereof to maintain engagement with the inner wall of pipelines within a range of diameters without increasing the drag thereon, the second drive member further including a flexible backing disc rearward of the primary drive elements and adapted to seal against the inner wall of the pipeline for all bent positions of the primary drive elements.
9. A pipeline pig as claimed in claim 8 and including a plurality of circumferentially spaced return path elements surrounding the body member and each extending axially relative to the body member, each return path element including a pair of axially spaced magnets from each of which projects a metallic bristle set, means for connecting the return path elements to the body member whereby the free ends of the bristles, in use, resiliently engage the inner wall of the pipeline, said connecting means comprising a first carrier member mounted on, to be axially slidable relative to, the front extent of the body member and resiliently urged towards the rear of the body member, the first drive member being mounted on said first carrier member, a second carrier member mounted on, to be axially slidable relative to, the rear extent of the body member and resiliently urged towards the front of the body member, and, for each return path element, a front link pivotally interconnecting the front of the return path element and the first carrier member and a rear link pivotally interconnecting the rear of the return path element and the second carrier member, and a plurality of drive struts each having a one end and an other end, the one end of each of which is pivotally mounted to the support element of the second drive member and the other end of each of which is pivotally mounted to the rear regions of the return path elements at or adjacent the other end of an associated link, the drive struts being arranged so that, in the event that drive of the pig is by way of the second drive member, the applied force from the second drive member to the return path elements has a substantial component in the axial direction of the pig.