Abstract: This invention is a steel door prop to simulate a typical hollow metal frame, a plywood door with either a reusable metal edge or a disposable metal edge and a reusable lock. The door prop can also be used with a conventional door. The invention is designed to be used by fire departments, military, and law enforcement agencies to train personnel in the art of opening locked or blocked doors. The special benefits to the invention are versatility, portability, and cost savings.

Abstract: A training device is described for perfecting the art of forcibly opening a door in an emergency. The training device has a frame and a door placed in the frame. A dead bolt is mounted in the door and protrudes from the door in a locked position relative to the frame. A vise is attached to the frame. The vise has a movable jaw mounted on a block and a stationary jaw, and means for tightening the movable jaw against the dead bolt. The dead bolt protrudes from the door between the stationary and movable jaw. A method of using the training device causes the door to pivot and the dead bolt to move off of the vise, thus simulating an actual forced opening.

Abstract: An electronic teaching device for teaching addition and subtraction to students in the primary grades. The device is of simple construction utilizing digital electronic components. The invention utilizes an enclosure or box which invites students to use the device as a toy or game while facilitating learning of simple mathematical tables. In the preferred embodiment the student gains access to the box, and a reward, which may be placed inside it, if he correctly completes a simple algebraic equation which had previously been setup by a teacher.