US2415203A - Dental engine attachment - Google Patents

Description

Feb. 4, 1947. H. FREEDMAN DENTAL ENGINE ATTACHMENT Filed June 'r, 1945 INVENTOR Patented F ch. 4, 1947 DENTAL ENGINE ATTACHMENT Hyman Freedman, New York, N. Y., assignor of one-half to Bertha Freedman, New York, N. Y.

Application June 7, 1943, Serial No. 489,901

9 Claims.

This invention relates to improvements in dental engines and has particular reference to a supporting means forthe hand piece or dental tool.

Heretofore, it has been the common practice to provide a supporting hook on the extension arm of a dental engine from which hook the hand piece is suspended when not in use. In actual practice, a dentist, during an operation, has many occasions to replace the hand piece in its suspended position on the hook and often does so Without observing whether the tool is secure thereon. As a consequence it is not uncommon for the tool to become accidentally detached and fall from its hook with considerable force and strike a patient with the possibility of serious injury. In fact, only recently, an accident of this nature happened and a drill attached to the hand piece penetrated a patients skull, resulting in her death.

To minimize the possibility of such unfortunate accidents, it is proposed, by the present invention, to provide additional means supplementing the customary supporting hook which Will effectively prevent the fore arm that carries the hand piece from falling in the event that said hand piece should become accidentally detached from said hook while in a suspended position thereon.

Accordingly, a feature of the invention is to provide means associated with the extension and fore arms of the dental apparatus and preferably arranged adjacent the pivotal connection between said arms, which means will become efiective to retain the fore arm in the position it assumes when the hand piece is suspended on the supporting hook should said hand piece become accidentally detached from said hook.

A further and more specific feature is to mount a permanent magnet on one arm of the apparatus in such manner that said magnet will remain in magnetically opposed relation to another arm in respective of any turning movement of the first named arm relative to said magnet.

The inventive idea involved is capable of receiving a variety of mechanical expressions some of which, for purposes of illustration, are shown limits thereof, reference being had to the ap pended claims 1? or this purpose.

In the drawing: Fig. 1 is a fragmentary elevational view of a dental engine of conventional form, showing the present invention applied thereto. Fig. 2 is an enlarged side elevation of the magnetic means for retaining the extension and fore arms in their inoperative positions.

Fig. 3 is a section on the line 33 of Fig. 2.

Fig. 4 is a section on the line 4-4 of Fig. 2.

Fig. 5 is a section on the line 5--5 of Fig. 2.

Fig. 6 is a view similar to Fig. 2, partly in section, showing a modified form of the invention, and

Fig. 7 is a section on the line '!-'I of Fig. 6.

Referring more particularly to the drawing, the numeral It indicates a portion of the engine arm of any conventional type of dental engine, which arm is provided at its outer end with the upper pulley H around which passes the usual drive belt A2 for the hand piece IS. The extension arm E l has a universal pivotal connection at its upper end with the arm IB and, at its lower end, has a similar connection with the lower end of the fore arm [5. An idler pulley I6 is also located at the lower ends of said arms and the belt I2 also engages around said pulley and then extends upwardly and around the pulley I! at the upper end of the arm is, and from thence to the drive pulley IS on the hand piece [3. The upper end of the arm l5 has the usual universal connection with an arm 19 which carries said handpiece l3 and, when the latter is not in use, it is engaged with a supporting hook 26 attached to the extension arm M adjacent-its upper end. The construction thus far described is well known in the art and therefore requires no further ex planation.

In accordance with the present invention, means are provided for releasably retainingthe arm 15 in its suspended or inoperative position shown in Fig. 1 in the event that the arm l9 should become accidentally detached from the hook 2t, and thereby prevent said arm IE, together with the hand piece i3, from falling away from said hook. Said means is desirably positioned between and associated with the lower ends of the arms M and i5 and preferably takes the form of a permanent horse shoe magnet 2! supported on the arm l4 and a keeper 22 carried by the arm E5. As will be evident, said magnetic elements, when brought into proximity, will attract each other and the magnetic flux passing between the same will be sufiicient to hold the arms 54 and i5 in their suspended or inoperative positions even though the arm I9 is disengaged from the hook 29.

In order to support the magnet 25 on the arm 14 so that said magnet will remain in opposed relation to the keeper 22 regardless of any axial turning movement of said arm, a casing 23 is provided for said magnet, which casing is made of any suitable non-magnetic material such as brass. Said casin comprises side walls 24 between which the magnet is received and wherein it is secured by a rivet 25. One end of said casing terminates in opposed resilient clamping portions 26 which are engageable about the sleeve 21 in which the arm I4 is rotatable. Said sleeve extends upwardly from a rectangular member 28 upon which the lower ends of the clamping portions 25 rest and, in order to prevent any rotation of the casing while the arm I4 might be rotating in said sleeve, said clamping portions are provided with depending extensions 29 which engage opposed faces of the stationary portion 28.

The support for the keeper 22 is somewhat similar in construction to that of the magnet 21. Thus, as best shown in Fig. 5, said support comprises a member 36 having opposed clamping portions 3i which partially embrace a sleeve 32 carried by the upper end of a rectangular member. 33, and extensions 34 on the lower ends of the clamping portions 3i engage opposed faces of the member 33 so that said support will not turn if the arm 15 is rotated. The keeper 22 is resiliently carried by the suport 30 by means of two coil springs 35 interposed between and secured to said support and keeper, this construction enabling the keeper to at all times haveflush en- I gagement with the pole pieces of the magnet 2!. Also, by providing a mounting of this character for the keeper and having the springs 35 of proper tension, it will be observed that as said keeper approaches the magnet toward the end of the movement of the fore arm to its inoperative position and before the hand piece is engaged with the hook 2d, the magnet will become effective to attract said keeper and thus hold said fore arm in said position even if the hand piece should not be engaged with the hook.

In such construction it will be noted that as the forearm I is moved toward the extension arm It, the keeper 22 will move forward into engagement with the permanent magnet 2| at an accelerated speed. Upon engagement of the kepeer with the permanent magnet an audible sound or signal is heard which immediately indicates to the operator that the magnetic lock has been made effective. On the other hand, if the aforementioned arms, upon relative movement toward each other do not produce an audible sound or signal the operator is warned of the failure of the securing means to become effective.

In the form of the invention shown in Figs. 6 and 7, the magnet 36 is mounted on a support 31 which is of substantially the same construction as the member .23 and is carried on the sleeve 2! associated with the arm M. However, instead of providing a keeper on the arm l5, the sleeve 38 in which said arm is rotatable is made of magnetic material and is directly engageable with the pole pieces 33 of the magnet 35 when the arms M and P5 are in their inoperative positions.

What is claimed is:

1. .In a dental engine, pivotally connected extension and-fore arms the latter of which has v an infinite numer of inoperative positions, one of said positions being adjacent said extension arm, members in which both said arms are axially rotatable, magnetic elements supported by said members in opposed relation to each other and disposed adjacent the pivotal connection between said arms, and means to retain said magnetic elements in such relation irrespective of any rotary movement of either of said arms.

2. In a dental engine, pivotally connected extension and fore arms having an infinite number of inoperative positions, said fore arm having an inoperative position adjacent said extension arm, a member including a sleeve, in which one of said arms is axially rotatable, a removable casing positioned adjacent the pivotal connection between said arms and having clamping portions engageable with said sleeve said casing having means engaging said member to prevent rotation of said casing when said arm is rotated, and a magnet supported by said casing contiguous to said pivotal connection and operatively associated with the other of said arms to retain said fore arm in its inoperative position.

3. In a dental engine having a forearm, an extension arm, and means for mounting a tool on said forearm, primary locking means for supporting said forearm in a first locked position, and secondary locking means for supporting said forearm in a second locked position adjacent said firstposition, said secondary means including mechanism actuated by movement of the forearm to a point proximate either of said locked positions.

4. In a dental engine having a forearm, an extension arm, and means for mounting a hand tool on said forearm, primary means for supporting said forearm in a first position, and secondary means for supporting said forearm in a second position adjacent to and spaced from said first position, said secondary means comprisin a member mounted on one of said arms, and a second member mounted on the other of said arms and actuated to connect with said first member upon movement of said second member to a point proximate said first member and before said other arm has reached said second position.

5. In a dental engine having a forearm, an extension arm, and means for mounting a hand tool on said forearm, primary means for supporting said forearm ina first position, and secondary means for supporting said forearm in a second position adjacent said first position, said secondary means comprising a fixed member mounted on one of said arms and a movable member mounted on the other of said arms adapted to connect with said fixed member upon movement of either of said members toward the other.

6. In a dental engine having aforearm, an extension arm and means for mounting a tool on said forearm, primary means for supporting said forearm in a first position, and secondary means for supporting said forearm in a second position adjacent said first position, said secondary means, comprising a magnet fixedly mounted on one of said arms and a keeper bar resiliently mounted on the other of said arms, said keeper bar being actuated to connect with saidmagnet when one of said arms is moved to a point proximate said first position.

7. In a dental engine having a forearm having an infinite number of inoperative positions, an extension arm, and means for mounting a tool on said forearm, a first and second inoperative positions for said forearm, said second inoperatve position being spaced from said first inoperative position, means for retaining said forearm in said first inoperative position, and means for retaining said forearm in said second inoperative position, said last means becoming efiec- 5 tive as said forearm moves from said first inoperative position to said second inoperative position. as

8. In a dental engine having a forearm having an infinite number of inoperative positions, an extension arm, and means for mountin a tool on said forearm, means pivotally connecting one end of each of said arms, said forearm having a first inoperative position and a second inoperative position adjacent said first position and magnetic means disposed on at least one of said arms adjacent said pivotal connection for maintaining said forearm in said second position.

9. In a dental engine as described in claim 8, and means for supporting said forearm in its first inoperative position, said last means comprising a hook mounted on said extension arm. said hook being engageable by said tool mounting means.

HYMAN FREEDMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,198,227 Hinchey Sept. 12,1916 1,340,908 Pieper et a1 May 25, 1920 2,288,688 Dubilier July 7, 1942 148,920 Bonwill Mar. 24, 1874 1,495,673 Cliffton May 27, 1924 1,037,134 Cottle Aug. 27, 1912 1,038,752 Hofbauer Sept. 17, 1912 2,188,034 Darby Jan. 23, 19 10 2,286,740 Krause June 16. 1942

Images