Abstract: A vandal-proof door and a vending machine equipped with the unique door. The door strengthens and reinforces coin operated vending machines, while providing the customer with a clear, unobstructed view of the product selection inside the machine. The door comprises a rigid, generally rectangular frame having a pair of spaced-apart sides that border a product viewing aperture. An outer, arcuate impact panel having a convex vertical cross section overlies the viewing area. The impact panel is flexibly mounted to the door by elongated, resilient extrusions secured to the frame edges. Similar resilient extrusions receive the top and the bottom of the impact panel. A separate, spaced apart translucent window is internally mounted on the door frame adjacent the viewing area. Gasket sealing material is secured about the panel and window edges to complete a seal. An isolated air pocket is thus defined between the outer impact panel and the inner window.

Abstract: A pressure sensing device has a light source, and an optical sensor for externally sensing a predetermined change in the pressure within a sealed system which has a conventional gauge. Illumination from the light source is reflected off of the gauge dial and detected by the optical sensor. When the pressure in the sealed system changes a predetermined amount, the needle on the gauge moves so as to interrupt the illumination reaching the optical sensor. The optical sensor in turn produces a voltage that can be used to turn on a light or other indicator.

Abstract: A can vending apparatus with a hollow chute oriented at an angle with respect to the horizontal, an electrical control circuit, a first and a second mechanism, and an electrically operated horizontal sliding vending door. The two queuing mechanisms and the vending door are operated in sequence by the electrical control circuit. Products are permitted to slide down the hollow chute and are queued between the two queuing mechanisms. The products are permitted to enter the vending area, one at a time, on top of the sliding door under the control of the electrical circuit. At selected intervals of time the vending door is retracted by the electrical control circuit to dispense the product to be vended.