This relates to machines for producing concrete products such as concrete pipe, manholes, catch basins and the like. Such machines are used to produce pipe in a dry cast operation which involves the three basic steps of filling the forms, pressureheading the concrete in the forms and then stripping the forms from the pipe and allowing them to cure. As is well known, the three basic operations are performed simultaneously at three separate stations, and three form sets are mounted at equally spaced stations on a turntable that is controllably rotated so that each of the operations can be performed on each form set as it is rotated into the filling, pressureheading and stripping stations. In this manner, the three-station turntable allows three different pipe sizes or types to be produced side by side in a single cycle of operations that occurs during one complete rotation of the turntable. An example of a machine of this type is shown in U.S. Pat. No. 4,708,621 which shows a machine capable of producing multiple forms at a single station of the turntable.
At the present time, each of the dry cast operations are performed manually by operators which operate controls to fill the forms, pressurehead them and then strip them. This usually requires three men, one to control the basic turntable operation, a crane operator, and a third man who cleans, oils and loads the headers at the pressureheading station. Although machines of this type are quite efficient, they do require considerable manpower and training to produce quality concrete products. Automation of machines of this type would increase the efficiency of the operation, provide more consistent quality of the finished product and lessen the manpower and physical labor involved in producing concrete products of this type. However, with machines of this type, the pipe forms are anchored only at the bottom on the turntable to provide for faster changeover from one form set to a different form set. Moreover, since operating conditions in concrete pipe plants are not always perfect nor consistent from plant to plant, any automated machine must be capable of self-alignment between the form sets and the operating components and must also be capable of overcoming known imperfections and inconsistencies in plant operations.
There is therefore a need for an automated pipe making machine that can achieve a high level of production output while still permitting versatility and flexibility to allow quick and easy changeover from one form type or size to another.
There is also a need for an automated pipe making machine that is simple to operate and requires a minimum of operator training, and yet one that will work dependably in a variable and imperfect pipe plant environment.
In order to achieve these objectives, such a machine must provide an automated feeding system and a flexible and versatile pressureheading system to accommodate various pipe sizes and types that might be run side by side on the same turntable.