Abstract: The present invention is an automatic filter cleaning system which includes a solvent dewaxing filter which removes wax from a wax mix slurry and provides a filtrate. Status control apparatus is connected to the filter for affecting the operational status of the filter. Drain apparatus responsive to a control signal controls draining of the filter. Cleaning apparatus is also connected to the filter. A control network connected to the status apparatus, the draining apparatus and the cleaning apparatus controls those apparatus in a manner so as to allow selective changing of the status of the filter from an operational state to a down state to automatically drain the filter and clean the filter while the filter is in the down state.

Abstract: A ball-delivering-and-catching device the structure of which allows a ball or the like to roll back and forth thereon and then fly into the air moving along a parabolic path before falling down into or outside a catching hoop if a user grips a handle of the device and adequately sways the device forward and backward. Catching hoops with different shapes showing desired ball games may be used along with matching ball of achieve more fun. Furthermore, different pictures or cards showing different ball games may be selectively inserted into grooves formed on a backboard of the device to enhance the excitment.

Abstract: A spark-producing mechanism for wheel assembly comprises a plurality of flints, a fixing ring for the mounting of flints which closely fits to the shaft of the wheel, a grindstone which is inserted in the interior of the wheel. By rotating the wheel, the flints rub against the grindstone to produce sparks.

Abstract: An articular support system for dental model sets includes a fixture having an upper portion carried by a lower base portion. The base portion has a base plate which connects with an inner support post. This post is formed with a vertically extending inner passageway. The upper portion includes an inner and outer plate connected by a releasable hinge. To use the system a base of a dental model of a person's upper teeth and lower teeth are each molded with front and rear indentations. Each model then fits into a bracket having spaced apart end walls. On an inner side of each end wall is a locking tab that fits into the respective model indentations. The lower teeth model bracket next is affixed to the fixture base plate with mastic. The upper model teeth then are placed in contact with the lower model teeth to reproduce the bit that occurs inthe person's mouth. Next, the upper portion inner plate is loosely positioned in the base portion post passageway.

Abstract: An arithmetic counter that includes a U-shaped support structure for a horizontal rod. Consecutively numbered beads are slidably arranged on the rod for adjustment to positions wherein selected numbers of the beads are separated from the remaining beads. One or more marker boards are adopted to be hung from the rod between the separated beads and the remaining beads, such that a small child can count the beads and achieve and better understand "addition" and "subtraction" processes.

Abstract: A pipe trough for transporting pipe between upper and lower positions. A pipe carrier having a V-shaped cross-section is received within an elongate trough body having a V-shaped cross-section. The pipe carrier is longitudinally slidable along the trough and is constructed to receive one end of a pipe. A roller is mounted at one end of the trough body for supporting the other end of a pipe received within the carrier. A hydraulic motor is provided for selectively moving the carrier along the length of the trough body. Openings formed crosswise of the trough are distributed along its length. Each opening includes a pipe unloading arm having a pivotal connection to the trough at one side. A ram positioned beneath the arm and having one end pivotally attached to the arm and the other end pivotally attached to the trough is provided for raising and lowering the arm to unload the pipe from the trough.