1. Field of the Invention
The present invention relates to a machine for rapidly and efficiently forming building blocks from compactible material, and more particularly to such a machine which is provided with means for internally increasing the output pressure of the block forming hydraulic ram of the machine.
2. Description of the Prior Art
The use of earthen blocks as a building material has been known for centuries. Earth is available in unlimited supply at no expense, and it is available at the site of construction. Additionally, earth is non-toxic, non-allergenic, fireproof and soundproof. The high inherent insulating properties also enhance its desirability as a building material.
In somewhat recent years the earth at the building site has been fashioned into building blocks in a press and required compacting the earth material in a suitable machine having a hydraulic cylinder enclosing a ram piston. The ram exerts an output pressure against contained earth material to compact the earthen material into a block. In order to form the blocks at the construction site it is desirable to provide a machine which is portable and which is capable of providing sufficient pressure to form the earth into solid blocks. One such machine is disclosed in U.S. Pat. No. 4,569,649 issued to Robert Gross on Feb. 11, 1986.
It has been found that, although the machine identified above produces hydraulic pressures of 3,000 psi (210 kg./sq. cm) during the final stages of the block formation, such pressures do not compact the earth material sufficiently. One example, is the noticeable undesirable feature that the corners of the block tend to break away under slight pressure, thus leaving an incomplete ill formed block.
What is needed then is a machine which is relatively lightweight and portable and is transportable to the site and which should be capable of producing extremely high pressures which are capable of substantially xe2x80x9cbondingxe2x80x9d particles of the block forming material into a stable mass which will not xe2x80x9ccrumblexe2x80x9d or otherwise fail under high external pressure.
The present invention provides a machine for forming building blocks from compactible materials, such as earth and other materials, as discussed hereinbelow. The machine overcomes the above noted deficiencies of previous machines by providing means for dramatically increasing the output pressures at which the block forming hydraulic ram exerts against compactible material held in a block forming mold of the machine.
To accomplish this pressure increase, a pressure intensifier hydraulic actuator is coupled into the ram cylinder for coaction therewith to dramatically increase the output pressure of the ram cylinder and thus provide a very high degree of bonding pressure of the particles forming the block.
It is, therefore, an object of the present invention to provide a machine for forming blocks from compactible material.
It is a further object of the invention to provide such a machine with means for increasing the output pressure of the block forming hydraulic ram which compacts the compactible materials into blocks of predetermined configuration.
These and other objects and advantages are accomplished by the present invention of a machine for making blocks from compactible material, such as earth etc. The machine comprises a block forming mold and a ram head. The ram head is capable of moving between a retracted position in which the head is removed from the mold, and the compactible material can fall through a bottom opening of a hopper which is moveable into and out of registry with an upper opening of the mold, and an advance position in which the head is moved into the mold and the compactible material is highly compressed to form a block. A hydraulic actuator cooperates with the ram cylinder to increase the output pressure of the ram.