Abstract: A dental handpiece comprising a drive section with a drive shaft for driving a tool receiving socket mounted for rotation in an end of a handle section which handle section is coupled for relative rotation on the drive section, said dental handpiece having at least one cooling medium line being formed by a line segment arranged in each of said sections for conveying the medium to a nozzle adjacent the socket, and a rotatable coupling for the cooling medium lines characterized by the rotatable coupling being formed by a first and second sleeves being telescopically assembled together for relative rotation, one of said sleeves having an annular groove for each of the cooling medium lines and the other of the two sleeves having a radial opening in communication with each of the annular channels, said sleeves being detachably connected to the respective section to rotate therewith.

Abstract: A dental handpiece with at least two drive shaft sections for transmitting the rotary motion from a drive motor to an acceptance socket which is rotatably mounted in a head part of the handpiece, each of the drive shaft sections being arranged with their axes at an angle to one another and one of the two drive shaft sections having two coaxial gears which have different numbers of teeth and the other drive shaft section having at least one gear characterized by one of the two sections being mounted for axial displacement between two positions with one of the positions having one of the two gears in engagement with a gear and the other position having the other of the two gears in engagement with a gear. The gears on the drive shaft sections can be selected so that in one of the positions a direct drive can be obtained and in the other position either a step-up or step-down ratio can be obtained. In one embodiment, a single gear of the one section coacts with the two gears of the other section.

Abstract: A device for releasably connecting two parts together characterized by a projection on one part slideably received in a socket or recess of another part to prevent twisting and to guide the two parts as they begin at connection until stop surfaces abut to define the final connecting position and a connecting mechanism having at least one pair of connecting elements mounted on the parts with one connecting element of the pair having an engagement surface for engaging the other element of the pair and being mounted for rotation on the one part with the engagement surface moving in an arc between an unlocked position to a lock position and the mechanism includes a resilient member acting on the one element to urge the engagement surface along the arc at least during the last part of travel towards the lock position so that two parts are held in a final connecting position by the resilient element acting on the one element.