US420876A - Henry ii - Google Patents

Description

NoModel.)

H. H. JOHNSON 8; S. G. HILL. RUBBER DAM CLAMP.

No. 420,876. Patentedf'eb. 4, 1890- UNITED STATES PATENT OFFICE.

HENRY H. JOHNSON AND SYLVESTER G. HILL, OF LONDON, ENGLAND; SAID HILL ASSIGNORfiO SAID JOHNSON.

RUBBER-DANI CLAMP.

SPECIFICATION forming part of Letters Patent No. 420,876, dated February 4, 1890.

Application led May l1, 1889. Serial No. 310,412. (No model.)

To all whom t may concern.-

Be it known that we, HENRY I-I. JOHNSON and SYLVESTER G. HILL, citizens of the United States, residing at London, England,

I; have invented new anduseful Improvements in Rubber-Dam Clamps, of which the follow'- ing is a specification. A

In illinglabial cavities in incisors, cuspids, and bicuspids, where such cavities extend to 1o or under the gum, itis necessary tohave free access to the cavity and perfect freedom from moisture, such as naturally arises from the moisture of the salivary glands. These necessities are provided for by the rubber-dam clamp for which Letters Patent No. 370,194: were issued September 20, 1887, to one of the present applicants; but in the former construction the clamp is made of sheet metal, and is held in place on the tooth by the in- 2c herent elasticity of a clasp or tongue, which rendered it necessary for security to tie the upper end of the device by a tape or cord passing around the head. While such device performs the functions for which intended, it is in a measure inconvenient and objectionable; and the objects of the present invention are to improve the prior construction; to provide a novel rubber-dam clamp which is firmly held in correct position by claws Without relying upon spring-pressure alone to secure it; to avoid theemployment of a tape for tying the clamp; to provide such a construct-ion that after the clamp is placed in position it can be adj usted to retract or raise the gum; to piovide a more rm, substantial,

and convenient device that can be fixed in position on a tooth and the gum retracted with little if any pain to the patient; to provide a rubber-dam clamp that can be adjusted as occasion demands; to provide means whereby the frame of the clamp having the Work-opening or the opening through which the dentist operates is held against movement in any direction, and to otherwise improve instruments of this type to render them more useful, efficient, and satisfactory, and lessen the discomfort of the patient. 4 To such ends our invention consists in a rubber-dam clamp combining in its structure a frame having a work-opening and adapted to retract or force the gum above the cervical margin of the cavity, and provided at its upper edge with a claw, an arm having a tongue point or claw to engage the inners'urface of the tooth, and means whereby the frame and claw-arm can be drawn toward each other to grip the tooth, and the frame and arm be adjusted one upon the -other in the direction of the length of the tooth.

The invention also consists in the construc- 6o tion and combination of parts hereinafter described and claimed, reference being made to the accompanying drawings, in whiel1-,

Figure lis a view showing the position of the clamp in use with a rubber dam; Fig. 2, a central vertical section from front to rear, and Fig. 3 a detail perspective view of the clamp on an enlarged scale. I

In order to enable those skilled in the art to make and use our invention, we will now 47o describe the same in detail, referring to the drawings, where the reference-numeral l indicates the frame composed of a metal piece bent into semi-lunar form with a shank 2, havinga longitudinal slot 3, and turned down at oneend at right anglesv and provided with a guidebearing a in the form of a sleeve l through which loosely passes an arm 5, provided at its outer end portion with a screwthread 6, on which is mounted a thumb-nut 8o 7. The upper edge 8 of the frame constitutes the gum-retractor, and is provided with a Aclaw-here shown as comprising two spurs or short prongs that are adapted to bear upon thelabial surface of the tooth and constitute a steady-rest which steadies, supports, and holds the frame in correct position. The inner end of the arm 5 is provided with a tongue point or claw 9, preferably a bifurcated projection, lto bearupon and engage the 9o inner surface of the tooth, and said arm is furnished with an attached screw-threaded stem lO, which projects up through the slot 3 in the shank 2 of the semi-lunar frame and carries athumb-nut l2, whereby the frame and arm can be drawn together and caused to iirmly clamp or grip the tooth between them, as represented'in Fig. 2. The slot 3 also permits the frame and arm to move l lengthwise in such manner that after the Ioo clamp is set or fixed in position upon a tooth the semidunar frame can be moved upward to retract or raise the gum above the cervical margin of the cavity to be iilled. This movement of the frame is conveniently eected by screwing up the thumb-nut 7 on the screwthreaded portion of the arm 5, such nut acting against the guide-bearing or sleeve 4 of the semi-lunar frame.

The adjustment of the parts and the tixing of the clamp in position by screws render the device more convenient, useful, and satisfactory in practice, while it can be applied and the gum retracted gradually, so that the patient suffers comparatively little it any pain or discomfort. Y

The frame and arm are preferablycom posed of spring metal, so that the device is clamped with a yielding pressure.

The rubber dam 13 is composed of a thin sheet of rubber, and is applied as fully explained in the Letters Patentbefore alluded to, and as shown in Figs. l and i of the drawings. This dam, as usual, is provided with a tape 14, or similar means, to pass around the head and support the dam in position so that the lip and gum are covered.

By careful and scientific adjustment to the anatomy of the tooth the clamp can be firmly fixed in position with comparatively no pain tothe patient, and it provides ample access through the work-opening of the frame to the tooth for filling and other operations.

Having thus described ourinvention, what we claim is l. Arubber-dam clamp comprisinga frame having a work-opening, and a laterally-pro jeeting claw located at its top edge to bear upon the labial surface of a tooth and form a steady-rest for the frame, an arm having a lateral claw at its upper end, which projects toward the lateral claw on the frame to en- 4o gage the inside surface of the tooth, and devices for moving the frame on the arm and .clamping the claws on the tooth, substantially as described.

2. A rubber-dam clamp comprisinga semilunar frame having a work-opening, a longitudinal slot and a claw at its upper edge, an arm having a claw and on which the se1nilunar frame is movable, a screw for adjusting the frame on the arm, and a screw on the 5o arm extending through the slot in the frame for adjusting the arm and frame toward each other to grip a tooth between the claws, substantially as described.

3. A rubber-dam clamp comprising an arm having a claw at one end and a screw-thread at the opposite end, a frame having a longitudinal slot, a work-opening, a claw at its upper edge, and a sleeve at its lower edge,

through which the arm loosely passes, a screw- 6o

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