Abstract: A dental unit has dental instruments carried by individual nests, the nests being selectively movable from a storage position to a readiness position. Each nest is carried to the readiness position in a controlled manner such that the axis of the instrument becomes horizontal and moves downwardly as the instrument approaches the readiness position.

Abstract: A dental chair lift mechanism employing a parallelogram lift has a linkage arrangement which offsets the horizontal component of motion produced by the parallelogram lift so that the seat of the dental chair can be elevated in a substantially straight vertical path.

Abstract: An adjustable headrest for a dental chair having one lock for holding the headrest at an articulated position and a second lock for holding the headrest at an adjusted longitudinal position with respect to the backrest of the chair. The invention is a one hand operated lock release for operating both locks. The release can be constructed so that manipulation of a single member can accomplish sequential, independent or simultaneous operation of both locks.

Abstract: A dental apparatus retracts supply hoses connected to associated dental instruments. A coil spring is used within a housing. The hose is interposed between the windings of the spring. When the hose is extended, the radius of the coil contracts causing control switches to be activated. A ratchet engages dogs on the spring preventing unwanted retraction. Upon release of the ratchet, the coil spring expands drawing the hose into the housing.

Abstract: A dental chair having a backrest and a seat each of which is angularly adjustable about a common horizontal axis. A motor drives a linkage system which simultaneously angularly adjusts both backrest tilt and seat inclination to positions ranging from one in which the chair supports the patient in substantially sitting position, to one in which the patient is reclining with his head below the rest of his body. As compared to the seat, the angular motion of the backrest is relatively uniform over the range of adjustment, whereas most of the angular motion of the seat occurs during the middle 50% of the range.