US3050855A - Dental apparatus - Google Patents

Description

Aug. 1952 c. A. ELLIS 3,050,855

DENTAL APPARATUS Filed May 10. 1957 2 Sheets-Sheet 1 INVENTOR. CHARLES A. ELLIS i MM.

A TTORIIEY 1962 c. A. ELLIS 3,050,855

DENTAL APPARATUS Filed May 10. 195'! 2 Sheets-Sheet 2 INVENTOR. GHARLES A. ELL/S ATTORNEY ilnite States 3,050,855 DENTAL APPARATUS Charles A. Ellis, Hamden, Conn., assignor to Ritter Company, Inc., Rochester, N.Y., a corporation of Dela- Ware Filed May 10, 1957, Ser. No. 658,442 Claims. (CI. 32-26) the patient and enable the dentist to select the rate at which tooth material can be removed in accordance with the particular conditions under which the dentist is operating. For example, to quickly remove a large amount of tooth material, as is desirable during the initial stage of grinding or drilling, requires a relatively high speed of rotation of the drilling tool or burr; whereas for the subsequent drilling stages, where usually only small amounts of tooth material are to be cut away, as in the finishing operation, the burr may be rotated at a relatively lower speed. In the design of modern dental equipment, to provide a single handpiece driven over a speed range wide enough to take care of substantially all of the conditions under which the dentist may be required to operate would involve a mechanism which is complicated, expensive, and inefiicient in operation. As far as is known, the dental handpieces in use today are operable only within a limited speed range and thus do not perform satisfactorily where speeds outside of this range could be used to more etfectively carry out a specific operation.

In order to overcome the limitations of the limited speed range in a single handpiece, two handpieces have been employed which are driven over a difierent range of speeds so that each handpiece may be selectively used to obtain the particular operating speed within its speed range. However, it can readily be appreciated that in addition to the cost of the two handpieces, a completely separate driving mechanism including a separate motor for each handpiece adds considerably to the cost of the complete unit and increases its size considerably. This objectionable aspect has been partially overcome in some prior constructions, where a single driving motor has been employed to drive both of the handpieces. However, the driving connections between the motor and the handpieces was complicated'and diflicult to adjust. Furthermore, these previous constructions required a change in the driving connections each time a change was made from one handpiece to the other.

Accordingly, a primary object of this invention is to provide a new and'novel driving mechanism for dental handpieces.

Another object of this invention is to provide a new and novel driving mechanism for a dental handpiece which is automatically connectedin driving engagement when the dental handpiece is moved from a stored to an operative position.

A further object of this invention is to provide a new and novel dental handpiece driving mechanism which permits selective operation of either of two dental handpieces driven over difierent speed ranges from a single motor wherein the handpiece selected for use is automatically engaged with the driving mechanism.

A still further object of this invention is to provide a new and improved driving'mechanism for dental handpieces which is simple and compact in construction, easy Patented Aug. 28, 1962 to maintain, attractive in external appearance and which is capable of prolonged use without risk of breakdown.

This invention further contemplates a dual drive from a single motor arranged so that the dentist has two handpieces available capable of being driven over a different range of speeds or, in the alternative, the dentist may use two handpieces of different types, one, for example, a straight angle and the other a contra angle handpiece, the drive being arranged so that the handpiece selected for use is automatically connected to the motor upon drawing the handpiece toward the position of work and disconnection of the drive from the motor is automatically effected upon restoring the handpiece to its position of non-use.

Other objects and advantages of this invention will be particularly set forth in the claims and will be apparent from the following description, when taken in connection with the accompanying drawings, in which:

FIG. 1 is a partial elevation view of dental apparatus incorporating the novel driving mechanism of the invention;

FIG. 2 is a partial plan View of the dental apparatus of FIG. 1;

FIG. 3 is an enlarged sectional view, broken away, taken substantially along line 33 of FIG. 1 in the direction of the arrows; and

FIG. 4 is a sectional view taken substantially along line 44 of FIG. 3 in the direction of the arrows.

As is well known in the practice of dentistry, it is highly desirable in tooth drilling and similar tooth cutting operations that the dental handpiece, containing the dental cutting tool, be driven at a selected speed which is governed, in general, by the amount of toot'material to be removed. In general, the greater the amount of tooth material to be removed, the greater the speed required. A variable speed within a single limited range has been obtained in previous constructions by the use of a foot pedal actuated rheostat or the like. However, it has been found in practice, that two widely separated speed ranges are most desirable to take care of most operating conditions encountered which can, for convenience, be identified as a high and low speed range. This dual range is best accomplished by the use of two handpieces and it is the purpose of this invention to provide a unitary driving mechanism for two such handpieces.

Referring now to FIG. 1, a support stand of any suitable type is provided which is designated generally by the numeral 1 1 and on which is supported a pair of dental handpiece assemblies, designated generally by the numerals 12, 13.

In accordance with the arrangement of the invention, handpieces 14 are provided on both of the handpiece assemblies 12, 13 and as both assemblies are similar in construction, a portion of assembly 13 including the handpiece has been omitted for clarity and only assembly 12 will be described in detail. The handpiece 14 is shown as a contra angle type but it should be understood that any suitable type of handpiece may be employed.

In the illustrated embodiment, handpiece 14 is preferably arranged to be driven in the high range (preferably 40,000 rpm. and up) while the handpiece of as sembly 13 is driven in the low range (preferably 2,000 to 8,000 r.p.m.). It should be understood that these speed ranges are illustrative only and that the scope of the invention includes driving each of the handpieces through any desired speed range. Furthermore, it should be understood that the motor is provided in the conventional manner with speed control means such as a foot pedal by which the speed of each handpiece may and boom 19 pivotally connected by suitable means at 20, 21 and arranged to support a handpiece driving belt 22. 16 maybe of any conventional construction such as commonly used today in dental apparatus of the type described. e

A handpiece driving motor, designated generally by V the numeral 23, is suitably mounted on the support stand 11 and is provided with a frame24 and a shaft 26 having opposite ends projecting outwardly from the frame 24 as shown in FIG. 3.

The folding bracket 16 is mounted at each end of the motor 23 by means of an annular member or support ring 27 suitably attached to one end of the boom 19 and offset from the axis of the boom at 25 as shown in FIGS. 2, 3. The ring 27 is rotatably mounted on a sleeve 28 having a portion 30 of reduced diameter. Each end of the motor frame 24 is provided with a sleeve 28, preferably integral therewith, through which the motor shaft 26 extends. The ring 27 may therefore rotate on sleeve 28 to pivot the boom 19 and additionally, may sliderelative to the sleeve in a manner to be more fully explained hereinafter.

In order to drive the handpieces 14 carried by the assemblies 12, 13, the driving belts 22 extend around pulleys 29, 31 freely mounted for sliding movement and rotation by means suchas roller bearings 32 on a sleeve portion 30 adjacent each end of motor shaft 26 as shown in FIG. 3. It will be noted that the offsetting of the ring 27 at 2'5 prevents interference of the belt 22'with its associated pulley. The pulleys 29, 31 are provided with peripheral grooves 33, 34, respectively, for receiving the belts 22. Each of the pulley grooves 33, 34 is of a selected depth or effective diameterto drive its associated belt at a predetermined speed. It will be noted that pulley groove 33 is shallower than pulley groove 34 so that the handpiece assembly-12 carries the high speed handpiece 14. The handpiece assembly 13 therefore carries the low speed handpiece.

shaft 26 comprising a clutch plate 39 carrying a friction disc or washer 41 fixed to its inner face. The clutch plate is suitably fixed to the shaft 26 by means such as.

pin 40. Movement of either of the pulleys 29, 31 axially outward into engagement with its associated clutch means or disc 41 when the motor shaft 26 is rotating, will result in a rotation of the pulley by the plate and drive the associated handpiece through the belt 22.

Means have been provided .to guide the movement of each ring 27 and to resiliently retain the ring against the motor frame 24 with its associated pulley out of engagement with the clutch disc 41 from the motor and more specifically, the ring 27 is provided with a plurality of arcuate slots 42 as shown best in FIG. 4. In the illus trated embodiment, there has been shown four of such arcuate slots 42, radially spaced on the ring and each provided with 'a portion of reduced width 43 forming a shoulder 44.

A guide stud 46 having a head 47 is positioned within each of the slots 42 and is threadedly engaged within a corresponding threaded opening 48 in the motor frame 24 as shown in FIG. 3. A spring 49 is positioned around the shank of stud 46 so as to lie between the bolt head 47 and a washer 50 which seats on the slotrshoulder 44.

In this manner, the boom ring 27 is resiliently held.

against the motor frame 24 with its associated pulley disengaged from the clutch disc '41, but is arranged to be moved axially outward along the frame sleeve 28 against the biasing action of springs 49. 1

In order to slide the ring 27 axially outward and con- It should be understood that the folding brackets sequently move its associated pulley intohandpiece driv-' ing engagement with friction disc 41, the ring contains cam means such as a cam or projection 51 on the outer edge of its inner face as shown best in FIG. 2. 7 The cam V 51 is arranged to seat in a correspondingly shaped depression. or recess 52 preferably positioned on the motor 7 frame. When the ring 27 is held in engagement with the motor frame by the spring 49 and its associated pul-' ley is disengaged from the clutch disc 41, the cam 51 will seat fully in the recess 52.

It can thus be seen that when the boom 19 is rotated together with the ring 27, the ring is cammed axially outward by the rising of cam 51 on the higher surface ofthe motor frame relative tothe recess 52 against'thebiasing action of springs 49. This outward movement bly 12 is shown in the stored or non-use position with the boom 19 pivoted upwardly to engage the ring cam 51 in recess 52. The handpiece 14 may be hung for convenience on a bracket 53 supported on the folding bracket rod 18. 'The pulley 29 has been moved toward the motor frame away from its associated clutch disc 41 the pulley. I

Either of the handpiece assemblies 12, 13 may be rotated from the stored position illustrated by assembly 12 in FIG. 1 downwardly into the position shown occupied by the handpiece assembly 13. The pulley is'thus drivably engaged as in the case of pulley 3-1 in FIG. 3 and the handpiece 14 may-now be operated by the dentist under the limited speed control permitted by the associated'foot pedal (not shown). As previously explained, the thrust bearing 36 permits substantially. frictionless rotation between the inner face of the pulley and the outer face of the boom ring 17. 7

'It can thus be seen that a single motor has been pro-I vided in which the motor shaft drives a dental handpiece I connected at each end thereof. By merely pivoting one of the handpieces' downwardly from a stored position,

the handpiece drive is connected automatically tov the rotating motor shaft so that the dentist need only use a foot .pedal control for controlling the speed overthe predetermined range leaving his hands free and greatly simplifyingthe speedchatngingoperation. 'It will also be noted that different speed ranges are easily established for each handpiece as the size of the pulley determines the speed in which the handpiece is driven. Although such an occasion would be rare, both handpieces could 55 be driven at the same time.

The important aspects of this invention are that no manually operated clutch or clutches are required. The

dentist automatically connects the drive of the handpiece having the range he desires to use during the act of moving the handpiece to the operative position. Correspond- 1 the invention is to provide pulleys of the same diameter or different diameters as shown and use two handpieces of different construction, for example, a straight angle handpiece and a contra angle handpiece. While there has been shown and described the preferred forms of mechanisms of the invention, it be apparent that various changes and modifications maybe made therein, particularly in the form and relation of parts, without departing from the spirit of the invention as set forth in the appended claims.

so that the motor shaft 26 may be rotated without driving 1 I claim:

1. Dental apparatus comprising, in combination, a dental handpiece assembly including a handpiece, a driving motor, means supporting said handpiece for swinging movement with respect to said motor, and driving means partially carried by said supporting means mechanically interconnecting said motor and said handpiece, said supporting means being arranged to move between a position wherein said handpiece is mechanically disengaged from said driving motor to a position drivably interconnecting said handpiece with said driving motor.

2. Dental apparatus comprising, in combination, a dental handpiece assembly including a handpiece, a driving motor having a shaft for driving said handpiece, means supporting said handpiece for swinging movement with respect to said motor between a driving position and a stored position and driving means including a clutch drivably connecting said motor shaft to said handpiece, said supporting means being arranged to engage said clutch and connect said driving motor to said handpiece when it is swung from a stored position to a driving position.

3. Dental apparatus comprising, in combination, a driving motor having a shaft, a dental handpiece assembly including a handpiece and a boom supporting said handpiece for swinging movement relative to said motor shaft, driving means including a clutch drivably connecting said motor shaft to said handpiece, and cam means on said boom being arranged to engage said clutch and connect said driving means to said handpiece when it is swung from a stored position to a driving position.

4. Dental apparatus comprising, in combination, a driving motor having a frame and a driving shaft, a dental handpiece assembly including a handpiece and a boom for supporting said handpiece for swinging movement relative to said shaft between a stored position and a driving position, said boom having a support ring arranged to pivot and slide axially of said shaft, driving means drivably connecting said shaft to said handpiece including a clutch plate on said shaft, a normally disengaged pulley slidably mounted on said shaft, and belt means connecting said pulley to said handpiece, cam

means on said boom being arranged to slide said boom and engage said pulley with said plate when said handpiece is swung from a stored position to a driving position.

5. Dental apparatus in accordance with claim 4 wherein said cam means comprise a cooperating projection and depression arranged on said motor frame and boom ring for relative axial movement, and including means biasing said boom for axial movement in a direction whereby said projection is seated within said depression.

6. Dental apparatus in accordance with claim 4 wherein said pulley is connected to said boom support ring for axial movement therewith and said boom is provided with an offset maintaining said belt means in proper alignment with said pulley.

7. A dental drilling unit adapted to be controlled by a single motor controller comprising, in combination, a motor the range of speed of which is controlled by said motor controller, pulleys of different diameters mounted on opposite sides of said motor, means including a pair of clutches operatively connecting either of said pulleys to the motor, a pair of handpieces, means driving one of said handpieces from one of said pulleys, means driving the other of said handpieces from the other of said pulleys, a pivoted support for each of said handpieces and its driving means, each of said pivoted supports having a driving position and a stored position and means automatically engaging the clutch of the handpiece selected for use when the corresponding support is moved from its stored position to its operating position and disconnecting said clutch automatically when the support is returned to its stored position.

8. A dental drilling unit in accordance with claim 7 wherein said clutch of the selected handpiece is automatically disengaged when the support is returned to its stored inactive position and said automatic clutch engaging means includes means enabling a range of pivotal movement of said support with the support in its active position without disengaging said clutch.

9. Dental apparatus comprising, in combination, a motor, a support for said dental hand piece, a driving connection between said motor and said hand piece, means permitting said support to be shifted from a stored inactive position to a hand piece driving active position and means automatically mechanically engaging said driving connection with the motor when said support is shifted from the inactive position to the active position.

10. Dental apparatus in accordance with claim 9 in which the support is pivoted and clutch elements are carried by the support and by the motor which elements are engaged when the support is moved to its active po sition. 'il

Hanson Oct. 29, 1907 Neel Nov. 30, 1920

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