Dental handpiece

Claim 2

A dental handpiece comprising: a body portion and a forward end portion detachably connected to said body portion; said body portion being provided with an axial bore which opens at the forward end of said body portion, an axial slot formed in the inner surface of said bore, a lateral recess formed in said slot and a slide key in said slot normally urged to a position to close said recess, said slide key being normally urged by a spring to said recess closing position and being movable out of said position against the force of spring to a recess opening position; and said forward end portion having means for supporting a rotary dental tool and a shaft removably inserted into said axial bore of said body portion and being provided with a pin slidably engageable in said slot in said axial bore when said shaft is inserted into said axial bore so that said pin pushes said key out of said recess closing position and, upon relative rotation of said forward end portion to said body portion, engages in said recess, whereupon said key is restored to said original recess closing position and said pin and thereby said forward end portion are securely connected with said body portion so as to prevent relative axial and rotative movement therebetween.

Claim 3

The handpiece of claim 1, further including a slide member provided on the outside of said body portion and connected to said slide key, so that when said slide member is moved, said slide key is moved out of said recess closing position.

Claim 4

The handpiece of claim 1, wherein said axial bore of said body portion functions as a bearing for said shaft of said forward end portion.

Claim 5

A dental handpiece, comprising: a body portion having an axially centered bore at the forward end thereof; detachable dental tool supporting means including rearwardly extending shaft means on the rear end thereof insertable into the axial bore, and means for receiving a dental tool on the forward end thereof; transverse extension means projecting transversely outwardly from the side of the shaft means; means defining a slot extending lengthwise along the interior of the axial bore; means defining a notch in communication with the slot, the transverse extension means being guided by the slot into the notch during insertion of the shaft means into the axial bore; and means for preventing escape of the transverse extension means from the notch once the shaft means are inserted into the axial bore so as to restrain the dental tool supporting means against rotative and axial movement relative to the body portion, wherein the escape prevention means includes a reciprocative member mounted for sliding movement along the lengthwise slot between a locking position blocking passage of the transverse extension means between the lengthwise slot and the notch and a release position permitting passage of the transverse extension means between the lengthwise slot and the notch.

Claim 6

A dental handpiece, comprising: a body portion having an axially centered bore at the forward end thereof; detachable dental tool supporting means including rearwardly extending shaft means on the rear end thereof insertable into the axial bore, and means for receiving a dental tool on the forward end thereof; transverse extension means projecting transversely outwardly from the side of the shaft means; means defining a slot extending lengthwise along the interior of the axial bore; means defining a notch in communication with the slot, the transverse extension means being guided by the slot into the notch during insertion of the shaft means into the axial bore; and means for preventing escape of the transverse extension means from the notch once the shaft means are inserted into the axial bore so as to restrain the dental tool supporting means against rotative and axial movement relative to the body portion, wherein the escape prevention means includes a reciprocative member mounted for sliding movement along the lengthwise slot between a locking position blocking passage of the transverse extension means between the lengthwise slot and the notch and a release position permitting passage of the transverse extension means between the lengthwise slot and the notch.

Claim 7

The dental handpiece according to claim 4, wherein the slot extends axially along the interior of the axial bore.

Claim 8

The dental handpiece according to claim 4, wherein the lengthwise slot has a width representing the width of the shaft transverse extension means, and wherein the notch is disposed intermediate the ends of the lengthwise slot transversely to the length thereof, the depth and width of the notch representing, respectively, the length and width of the shaft transverse extension means.

Claim 9

The dental handpiece according to claim 6, wherein the notch extends depthwise circumferentially of the axial bore and widthwise longitudinally of the axial bore.

Claim 10

The dental handpiece according to claim 4 wherein the reciprocative member comprises a slide key mounted for sliding movement inside the lengthwise slot.

Claim 11

The dental handpiece according to claim 8, wherein the slide key is nestled conformably within the lengthwise slot to fair together the interior of the axial bore and the outer surface of the slide key, whereby unobstructed insertions of the shAft means into the axial bore is permitted.

Claim 12

The dental handpiece according to claim 8, wherein the lengthwise slot includes an extension portion to the rear of the notch, the slide key in the release position thereof being slidably mounted inside the rearward slot extension.

Claim 13

The dental handpiece according to claim 4, including means for displaceably positioning the escape prevention means for engagement with the transverse extension means, the escape prevention means being temporarily displaceable by the transverse extension means so as to permit entry of the transverse extension means from the lengthwise slot into the notch during insertion of the shaft means into the axial bore.

Claim 14

The dental handpiece according to claim 4, including an operator member slidably mounted on the outer surface of the body portion, and means for interconnecting the operator member with the reciprocative member whereby the reciprocative member is moved conjointly with the operator member.

Claim 15

The dental handpiece according to claim 12, including means for normally biasing the reciprocative member to the locking position.