Robert Boschgmbh

Richard Wolf

Ernst Dreher

Kurt Latzina

Reinhold Stroezel

Max Burklin

Hans Martin

Siegfried Spittler

A pneumatic tool includes a fluid motor with a rotor and passages for connecting the rotor with a source of fluid under pressure. A normally open valve is interposed in the passages and movable to a closed position in which it interrupts the flow of fluid to the rotor. An actuator is located on the rotor and operative, in response to the rotor exceeding a predetermined speed of revolutions, to move from a neutral into an actuating position in which it engages the valve and moves the same to the closed position thereof.

Rotary pneumatic tool with valve-closing pin actuated upon overspeed

A sound absorber for intermittent exhaust gas, particularly for use in connection with a compressed air operated motor employed, for example, in a hand grinder. The sound absorber is arranged predominantly in the housing of the motor and includes an exhaust air discharging channel having an alternately varying cross-section to define a succession of continuously alternating narrow and wide passages for changing continuously the direction of flow of the exhaust air about an angle that is always lower than 90.degree. with respect to the axis of the discharge channel so that the ratio of successive minimum and maximum cross-sections of the channel is at most 4:1. The discharge channel is terminated with a nozzle plate defining a plurality of outlet nozzles the central axes of which converge in the direction of flow. The discharge channel further includes at least one dead air space which in the case of a hand grinder is preferably formed by the interior of a hollow handle of the grinder and a portion of the discharge channel is divided by an air guiding partition into two partial conduits of different lengths and each communicating with one group of outlet nozzles.

Sound absorber for an intermittently discharged gaseous working medium

A pressurized medium powered device has a motor of the external rotor type, both the stator and the rotor of the motor having registering channels which communicate with one another across an interstice. At least one annular groove is provided in at least one of the rotor and stator components of the motor at the interstice, and at least one annular sealing element, such as an O-ring or a slotted ring of rectangular cross-sectional configuration is received in the annular groove with axial and radial play and is pressed into sealing contact with the components, and into sliding contact with at least one of the components, by the pressure of the pessurized medium. An annular depression may be formed in the other component in registry with the annular groove, and the sealing element may be partly received in such depression. At least one of the surfaces which bound the interstice is very smooth, which can be obtained by fine machining, surface contacting, or providing a layer of synthetic plastic material on such surface.

Pressurized medium powered device

An inner component of the fluid machine has an outer circumferential surface, and an outer component has an inner circumferential surface which eccentrically surrounds the outer circumferential surface. One of the components is rotatable relative to the other component. The inner component is formed with at least two pair of diametrically opposite guide slots each having an outer end open at the outer circumferential surface and an inner end, the inner ends communicating with one another and each of the guide slots receiving a sliding vane. The sliding vanes in the respective diametrically opposite guide slots are biased apart by at least one biasing spring located between inner ends of the guide slots.

Growing community of inventors

Stuttgart, Germany

Richard Wolf