Abstract: A pneumatic pressure sensor switch device for giving a warning signal if a pneumatic vehicle tire has too low pressure has a gas-filled chamber, separated from the inflation space in the tire by a first flexible diaphragm, and having another, second flexible diaphragm as its opposite wall, which has electrical contact means cooperating with a stationary contact point in the sensor. If the tire pressure is not too low, the first diaphragm is moved by the tire pressure to compress the gas in the said gas-filled chamber, which gas moves the second diaphragm out of contact with the stationary contact point. If the tire pressure drops below a certain value, the second diaphragm closes an electric circuit with battery and transmitter, so that a signal is given to the outside.

Abstract: A pneumatic sensor switch for giving a warning signal if a pneumatic vehicle tire has too low pressure has a gas-filled chamber, separated from the inflation space in the tire by a flexible diaphragm cooperating electrically with a metal part in the chamber to form an electric switch open at safe pressures in the tire and closed at dangerous lower pressures. There is an electric circuit with battery and transmitter to transmit warning signals to the outside if the switch is closed. There may be a second chamber with an electric switch contact, filled with gas at a lower pressure and also separated from the inflation space in the tire by a flexible diaphragm so that the contact is open at atmospheric pressure therein and closed by the diaphragm at higher pressures. The electric switches of both chambers are connected in series so that a warning signal is given only at pressures in the dangerous range, when both switches are closed, and not at atmospheric pressure nor at safe operating pressures in the tire.

Abstract: A pressure sensor that responds to a predetermined rate of change of pressure in the fluid medium comprises a housing that encloses a pressure chamber which has a divider wall that consists of a printed circuit board and a flexible diaphragm which is permeable. The divider wall serves to separate the pressure chamber from the pressure sensitive system in which the sensor is used. The sensor may be used in a pneumatic tire and in such use the flexible diaphragm will be deflected to activate a transmitter when the pressure in the tire changes at a hazardous rate. The sensor will not activate the transmitter when the rate of change of pressure is less than a hazardous rate of change.

Abstract: A pressure sensor that responds to a predetermined rate of change of pressure in the fluid medium comprises a housing that encloses a pressure chamber which has a permeable wall and flexible diaphragm that separates the pressure chamber from the pressure sensitive system in which the sensor is used. The sensor may be used in a pneumatic tire and in such use the flexible diaphragm will be deflected to activate a transmitter when the pressure in the tire changes at a hazardous rate. The sensor will not activate the transmitter when the rate of change of pressure is less than a hazardous rate of change.

Abstract: A roll-up door for a container body of a van or the like is provided with a winch which is located in a compartment formed in the header of the door. The winch is connected by flexible winding straps to the upper door panel and the lower door panel so that it is operable to drive the door between the open and closed position. The door panels are hingedly connected by hinges in which the hinge pin is located at the inner face of the door. Flexible sealing members are connected to each jamb and bear against a marginal edge portion of the outer face of the door when the door is in the closed position. A control system for controlling the direction of rotation of the reversible D.C. motor is provided which includes a master control circuit and a slave control circuit which is selectively operable.

Abstract: A pressure sensor that responds to a predetermined rate of change of pressure in the fluid medium comprises a housing that encloses a pressure chamber which has a permeable wall and flexible diaphragm that separates the pressure chamber from the pressure sensitive system in which the sensor is used. The sensor diaphragm will be deflected to activate a transmitter when the pressure in the tire changes at a hazardous rate. The sensor will not activate the transmitter when the rate of change of pressure is less than a hazardous rate of change.

Abstract: A roll-up door for a contained body of a van or the like is provided with a winch which is located in a compartment formed in the header of the door. The winch is connected by flexible winding straps to the upper door panel and the lower door panel so that it is operable to drive the door between the open and closed position. The door panels are hingedly connected by hinges in which the hinge pin is located at the inner face of the door. Flexible sealing members are connected to each jamb and bear against a marginal edge portion of the outer face of the door when the door is in the closed position. A control system for controlling the direction of rotation of the reversible D.C. motor is provided which includes a master control circuit and a slave control circuit which is selectively operable.

Abstract: A light-weight elevator platform for a load elevator of a truck or the like has a plurality of light-weight floor boards mounted in a rectangular frame which has support rails which extend across the frame and are located between adjacent floor boards. Side edges of the floor boards are mounted in channels which are formed in the side edges of the frame and support rail members. The support rail members are releaseably secured to the frame member.

Abstract: A control system for controlling the direction of rotation of the reversible D.C. motor is provided which includes a master control circuit and a slave control circuit which is selectively operable. The control circuit permits the movement of the door to be arrested at any time and to be reversed at any time by operating the master control and allowing similar control by means of the slave control when it is activated.

Abstract: A pressure sensitive electrical switch consists of a housing in which two pressure chambers are formed. The pressure chambers are separated by a flexible diaphragm. The flexible diaphragm is made from electrical conductive material. Conductors extend into the housing to provide terminals which are spaced from the diaphragm when the pressure in the two chambers is substantially equal. When a pressure differential is established between the two chambers, the diaphragm may be deflected into contact with one or other of the terminals of the conductors. In use, the diaphgram is connected in an electrical circuit and each of the conductors is connected in an electrical circuit such that when contact is made between the diaphragm and one of the conductors, the electrical circuit will be complete. Because the diaphragm is at least partially permeable, this switch is intended to be used to monitor changes in pressure which occur between the two chambers over a relatively short period of time.

Abstract: A roll-up door for a container body of a van or the like is provided with a winch which is located in a compartment formed in the header of the door. The winch is connected by flexible winding straps to the upper door panel and the lower door panel so that it is operable to drive the door between the open and closed position. The door panels are hingedly connected by hinges in which the hinge pin is located at the inner face of the door. Flexible sealing members are connected to each jamb and bear against a marginal edge portion of the outer face of the door when the door is in the closed position. A control system for controlling the direction of rotation of the reversible D.C. motor is provided which includes a master control circuit and a slave control circuit which is selectively operable.