Various types of conveyors have been utilized for conveying objects in industrial production lines. Objects may be conveyed from work station to work station individually or in groupings, depending on the object and the task to be performed. It may or may not be important to maintain any spacing or control of the objects during some or all of the travel. For example, apples being conveyed may simply be stacked randomly on a conveyor, while bottles being filled may be held rigidly in place by a filling machine that has received the bottles from a conveyor.
Certain conveyor belts (sometimes also called chains) are made of a plurality of interconnected links, driven by motors that engage the conveyor belt. Such conveying systems are commonly employed in the transportation of manufactured goods and articles, and for containers. With these typical systems, the motor drives a toothed drive sprocket that engages complimenting driving recesses or “dogs” formed on the conveyor belt. These drive units can be disposed in any number along the length of the conveyor belt. Such a drive unit and conveyor system is disclosed in U.S. Pat. No. 6,119,848 which is assigned to the assignee of the present invention, and is incorporated herein by reference in its entirety for all purposes.
Link type conveyor belts are sometimes designed having a knuckle/socket joint arrangement wherein one part of the link has a rounded knuckle and the opposite part has a socket formed by two extending edges. The knuckle of one link fits into the socket of a neighboring link. The knuckle is able to move in various directions within the socket, which allows for the conveyor system as a whole to curve and move.
The interconnected links typically have a platform member connected to or formed integral with the link's upper (conveying) surface. The platform member is generally shaped to match the neighboring platform members on other links such that the links can turn in a plane or twist while moving around curved sections of the conveying system, yet are also shaped such that the cracks and spaces formed between the links are minimized. The platform members can be connected to the links in several different ways. For instance, the platforms may have pegs extending therefrom which match corresponding slots on the links. Alternatively or additionally, the platforms can have snap springs which lock into place on corresponding sections of the links. Such a knuckle link with a platform surface member is disclosed in U.S. Pat. No. 6,209,716 which is owned by the assignee of the present invention and incorporated herein by reference in its entirety for all purposes.
In conventional endless loop conveyor systems, the conveyor belt (or chain) follows a path having a conveying section and a return section. In the conveying section the conveyor carries the conveyed objects from a process start point to a process finish point (depending on the application), and in the return section the conveyor returns from the finish point back to the start point. Thus, depending on the orientation of the conveyor, a substantial portion of the conveyor may not be used to actually convey objects at any given point in time. Accordingly, the cost of an endless conveyor per unit of active conveying section is increased due to the manner in which endless conveyors are conventionally configured and driven. The increased costs include original purchase, repair, maintenance, and/or installation costs for the length of the conveyor required along the return path.
Other conventional systems used to convey objects include “puck” systems, in which a freely moving puck carries a conveyed object along a conveyor. Pucks are often used to hold objects in a given orientation for a certain processing step. If the object is a container, the process may be filling, capping, etc. Guides along the sides of the conveyor may direct the puck along the direction of travel without leaving the conveyor. The puck may have movable parts for holding the object. The puck does not follow any track, but freely moves along a conveyor from station to station as desired. The puck may be gripped and/or aligned by a processing station (for example, a container filler) for a time, but the puck does not follow a defined track. Pucks can be problematical for various reasons. For example, because they are loose on a conveyor, pucks and their conveyed objects can be tipped over. Also, pucks may undesirably spin or move on a conveyor unless specifically guided since they do not follow any track. Further, different-sized pucks may be required if a line is to be converted from one object to another, which an be costly in terms of stocking and switching families of pucks.