US3191023A

US3191023A - Lighting device for dental and surgical procedures

Info

Publication number: US3191023A
Application number: US281138A
Authority: US
Inventors: Daryl D Sullivan; Arthur L Jones; Jr Eugene J Neal
Original assignee: Pelton and Crane Co; Corning Glass Works
Current assignee: Pelton and Crane Co; Corning Glass Works
Priority date: 1963-05-17
Filing date: 1963-05-17
Publication date: 1965-06-22
Anticipated expiration: 1982-06-22
Also published as: GB1023894A; DE1466879B1

Abstract

1,023,894. Surgical lamps. PELTON & CRANE CO. May 19, 1964 [May 17, 1963], No. 20517/64. Heading F4R. A lighting device for surgical or dental use consists of a light source with a horizontallyextending filament and a reflector shaped as a portion of an elliptic paraboloid other than a paraboloid of revolution with its longer dimension vertical, a shield being arranged in front and to the sides of the light source. The light source may be a double-ended tubular electric lamp with a coiled-coil filament and a filling containing iodine. It is supported between socket members 37 carried in tubular jackets 48 supported on walls 40 forming part of a light shield 23 arranged in front of the lamp 35. The shield 23 is supported from the frame 24 of the reflector 25 by bolts 51 carried on side pieces 44 attached to the shield, springs 53 between the pieces 44 and frame 24 and nuts 52 enabling the position of the lamp 35 and shield 23 to be adjusted relative to the reflector 25. The frame 24 is carried by hollow bearings 17 extending inwards from a yoke 16 connected by a series of pivoted arms (not shown) to a transformer mounted on an upright, the yoke and arms being hollow to allow the passage of electric wires to the lamp. The reflector is symmetrically curved on both sides of the vertical and horizontal central planes in smooth curves equivalent to a series of curved segments of radius decreasing away from the central line and with centres offset from the central line.

Description

J1me 1965 D. D. SULLIVAN ETAL 3,191,023

LIGHTING DEVICE FOR DENTAL AND SURGICAL PROCEDURES Filed May 17, 1963 4 Sheets-Sheet 1 I V a a 1 24 v 2] I IN N ORS F 2 EUGENE :r. EAL, 312., &Z,w.M+\-a1 ATTOR/VE Y5 June 1955 D. D. SULLIVAN ETAL 3,191,023

v LIGHTING DEVICE FOR DENTAL AND SURGICAL PROCEDURES Filed May 17, 1963 4 Sheets-Sheet 2 ATT'0E/VEY5 June 22, 1955 D. D. SULLIVAN ETAL 9 LIGHTING DEVICE FOR DENTAL AND sunexcm. PROCEDURES Filed May 17, 1963 4 Sheets-Sheet 3 5 MR ww M WUNA \M m MLOE &- T &JN A is M E w. LUN YHE E m bAEMm J1me 1965 n. D. SULLIVAN ETAL 3,191,023

LIGHTING DEVICE FOR DENTAL AND SURGICAL PROCEDURES 4 Sheets-Sheet 4 Filed May -17, 1963 ATTORNEYS United States Patent 3,191,023 LIGHTING DEVICE FOR DENTAL AND SURGICAL PROCEDURES Daryl D. Sullivan, Corning, N.Y., and Arthur L. Jones and Eugene J. Neal, .lr., Charlotte, NC; said Sullivan assignor to Corning Glass Works, Corning, N.Y., a corporation of New York; said Jones and Neal, Jr., assignors to Pelton and Crane Company, Charlotte, N.C., a corporation of North Carolina Filed May 17, 1963, Ser. No. 281,138 9 (Ilaims. (Cl. 12.40-41.15)

This invention relates generally to a lighting device for dental and surgical procedures, and more particularly to an improved lighting device for projecting light in a horizontally-oriented pattern to provide a beam of light for the illumination of the oral cavity or mouth area of a person to facilitate dental and surgical procedures.

Heretofore, a lighting device for illuminating the oral cavity of a person has been generally constructed with a wide horizontally extending reflector behind a frontally shielded light source so that the lighting device produces a beam of reflected light having a horizontally-oriented light pattern of limited vertical dimension for confining the area illuminated thereby to the general region of a persons mouth. In this way, the shining of light from the lighting device into the eyes of the person being treated is avoided. The light pattern produced 'by -a lighting device of this character has been limited to a relatively small area, and, accordingly, frequent re-positioning of the lighting device during the progress of the dental or surgical operation is often required.

Attempts to increase the pattern size of a lighting device of this character have not been regarded as 'being particularly successful, since an increase in .the pattern size of the light projected by the lighting device has been accompanied by a corresponding decrease in the intensity of the light reflected thereby.

Moreover, the wide horizontal span of the reflector employed in such a lighting device for projecting a horizontally-oriented light pattern is often indirectly responsible for the casting of shadows in the region of the oral cavity of a patient, while the patient is undergoing treatmen: by a dentist or doctor. In this respect, the dentist or doctor may frequently position himself in such a manner as to be disposed between the wide horizontal span of the reflector and the patient, thereby partially blocking the light beam projected by the lighting device and casting a shadow in the region of the oral cavity. Thus, the efficiency of lighting devices equipped with wide horizontal reflectors is commonly impaired in the above-described manner to prevent such lighting devices from di recting all of the light emanating therefrom onto the region of the oral cavity of a person.

The aforementioned problem associatedwith a lighting device having a reflector provided with a wide horizontal span for projecting a horizontally-oriented light pattern to illuminate the oral cavity of a patient has been recognized, at least to some extent, by the proposal of a vertically-oriented lighting device in which the reflector therefor is vertically elongated and has a rather narrow horizontal width. T 0 project a horizontally-oriented light pattern, the latter lighting device relies upon transparent panels which form a cover for the light source and the reflector and which are provided with a plurality of flutes arranged in such a manner that the beam of reflected light projected from the lighting device will be spread horizontally. The closed construction of the latter lighting device 'hinders proper cleaning thereof, thereby contributing to a gradual but steady loss of efliciency with respect to the light intensity produced by the lighting device in the light pattern for illuminating the oral cavity of a patient.

It is therefore an object of the present invention to provide a new and improved lighting device for dental and surgical procedures which projects a horizontallyoriented light pattern over an area of comparatively large size commensurate with the purpose of lighting devices of this character without sacrificing light intensity to provide for more eflective illumination of the oral cavity of a patient. By producing a horizontally-oriented light pattern extending over a large area, the number of times in which re-positioning of the improved lighting device may be required during the progress of dental and surgical operations is held to a minimum.

It is another object of this invention to provide a new and improved lighting device for illuminating the oral cavity of. a patient to facilitate dental and surgical procedures, wherein the improved lighting device utilizes a vertically-oriented reflector with a horizontally-oriented light source in the form of an incandescent filament extending perpendicular to and across the optical axis of the reflector. The improved lighting device projects a beam of reflected light having a horizontally-oriented light pattern for illuminating the region of the oral cavity with the horizontally-oriented light pattern possessing a given light intensity spread over a comparatively large area. The slimness of the improved lighting device afforded by the vertically-oriented reflector construction thereof allows the lighting device to be positioned quite close to the dentist or doctor and permits a wide range of movement on the part of the dentist or doctor in the vicinity of the patient and the lighting device without blocking of the beam of reflected light emanating therefrom so that all of the light projected from the lighting device will be directed onto the region of the oral cavity. The horizontally-oriented light pattern is achieved without the presence of physical flutes, either on the reflector or a transparent cover therefor, and the lighting device may have a head of open construction to facilitate cleaning of the reflector without requiring removal of any parts of the lighting de vice.

These and other objects of the invention which will be made more apparent as the description proceeds are accomplished by our new and improved lighting device which combines a frontally-shielded horizontally-oriented incandescent filament providing a light source and a vertically-oriented reflector of particular construction behind the light source with the :filament and the reflector being arranged in such a manner that the lighting device produces a beam of reflected light having a horizontallyoriented light pattern of large size for illuminating the oral cavity of a patient to facilitate dental and surgical procedures; The light source is provided by a so-termed qua-rtzline lamp manufactured by the General Electric Company of Schenectady, New York, which produces a high light intensity and causes a beam of reflected light having a high light intensity to be projected over a large pattern area when combined with the vertically-oriented reflector, while contributing to the slim nature of the lighting device because of its small size.

In the drawings FIGURE 1 is a perspective view of the improved lighting device as constructed in accordance with the present invention for illuminating the oral cavity of a person to facilitate dental and surgical procedures, the beam of light projected by the lighting device and the horizontallyoriented light pattern formed thereby being shown in phantom lines;

FIGURE 2 is an enlarged front perspective view of the lighting head for the lighting device shown in FIG- URE l;

FIGURE 3 is a transverse sectional view taken along the line 33 in FIGURE 2;

FIGURE 4 is a greatly enlarged longitudinal sections view of the light source for the lighting device; i

' FIGURE 5 is a longitudinal sectional view taken along the line 5-5 in FIGURE 2;

FIGURE 6 is an enlarged fragmentary transverse sectional View showing a portion of FIGURE 3 in enlarged form;

FIGURE 7 is an enlarged exploded perspective view, partially in section, and showing the mechanism for adjusting the focal position of the light source for the lighting device;

FIGURE 8 is a front elevational view of a reflector employed as a component of an exemplary lighting device constructed in accordance with the present invention, but with certain prism bands omitted from the reflector for purposes of clarity, and showing certain structural dimensions of the reflector;

FIGURE 9 is a transverse sectional view taken along the line 9-9 in FIGURE 8, and showing other structural dimensions of the reflector of the exemplary lighting device; and 1 FIGURE 10 is a longitudinal sectional View taken along the line Iii-10 in FIGURE 8, and showing the inner focal point of the reflector of the exemplary lighting device.

Referring more specifically to the drawings, FIGURE 1 shows the improved lighting device in accordance with the present invention as being mounted on the upright standard S of a dental unit. ing device comprises a head It) and a plurality of pivotally interconnected arms 11, 12 (see FIGURE 5), 13:,and 14the arm 14 remote from the head litl) being connected to a transformer 15 which is affixed on the top of the upright standard S for the dental unit. The head 10 may be pivoted horizontally or vertically for adjusting its position to beam the reflected light emanating therefrom in the desired direction. It will be understood that the illustration in FIGURE 1 is merely exemplary, as the head 14) may also be mounted on a wall or ceiling.

The arm 11 is provided with a yoke 16 which straddles the head 1th, the legs of the yoke 16 including laterally inwardly extending bearings 17. The bearings 17 are respectively journaled in the opposite sides of the head 16 for swivelly mounting the head it) within the yoke 16 for pivotal movement about an axis transverse to the longitudinal extent of the head It A wiring channel 20 is formed in the yoke 16 and extends along the length of each of its legs. The wiring channel Zil communicates with a wiring passageway through the connector arms 11, 12, 13 and 14 which leads to the transformer 15/ It will be understood that the transformer 15 may be conthe yoke 16 also communicates with the interior of the lighting head 10 through the

bearings

17, 17 disposed at opposite sides thereof.

Essentially, the lighting head It) comprises a reflector 21, a light source 22 disposed forwardly of the reflector 21, a light shield assembly 23 disposed forwardly'and to the sides of the light source 22, and a frame 24 for supporting the reflector 21, the light source 22, and the light shield assembly 23. a

The reflector 21 comprises a catadioptric member which is preferably molded from an integral piece of glass in a particular vertically-oriented shape so as to possess both transverse and longitudinal curvatures. By terming the reflector 21 a catadioptric member, it is meant that the reflector 21 also refracts light in addition to its reflection thereof. The rear reflecting surface 25 of the reflector In this connection, the lighttransmitting 21 has a shape which is substantially that of a portion of an elliptic paraboloid other than a paraboloid of revolution such that a vertical plane perpendicular to and bisecting the transverse center line of the reflector 21 will intersect the rear reflecting surface 25 along a verticallyoriented line substantially conforming to a portion of an ellipse and a horizontal plane perpendicular to and bisecting the longitudinal center line of the reflector 21 will intersect the rear reflecting surface 25' along a horizontally-oriented curved line composed of a plurality of curved segments forming a continuous curved line. In the latter respect, the horizontally-oriented curved line describing the intersection of a horizontal plane perpendicular to and bisecting the longitudinal center line of the reflector 21 with the rear reflecting surface 25' has a central curved segment provided with a greater radius of curvature than the radius of curvature of curved segments on opposite 'sides thereof; wherein the side curved segments have equal radii of curvature about respective points located in off-set, equidistant relation to a center line bisecting the horizontally-oriented curved line and on opposite sides thereof, with the greater radius of curvature of the central curved segment being measured from a point lying on the center line bisecting the horizontally-oriented curved line. The horizontally-oriented curved line has a maximum depth along its bisecting center line substantially less than the maximum depth of the vertically-oriented line formed by the intersection of a vertical plane perpendicular to and bisecting the transverse center line of the reflector 21 with the rear reflecting surface 25, which latter depth is measured along a center line bisecting the vertically-oriented line.

The shape of the rear reflecting surface 25 may be further characterized as having transverse and longitudinal curvatures symmetrically arranged on opposite sides .of the transverse and longitudinal center lines of the reflector 21. The transverse curvature of the rear reflecting surface 25 at the top and bottom of the reflector 21 may differ from the transverse curvature of therear reflecting surface 25 elsewhere along the rear reflecting surface 25,

as represented by the horizontally-oriented curved line previously described and identified as the rear reflecting surface 25 in the transverse sectional view of FIGURE 9. In this latter respect, the transverse curvature of the rear reflecting surface 25 at the top and bottom of the reflector 21 is composed of a continuous curved line comprising a central curved segment provided with a-radius of curvature smaller than the radius of curvature of the central curved segment representing part of the transverse curvature of the rear reflecting surface 25 present elsewhere therealong and a pair of side curved segments provided with equal radii of curvature about respective points equidistantly off-set from the point from which the radius of curvature of the central curved segment at the top or bottom of the reflector 21 is measured and on opposite sides thereof, the radii of curvature of the side curved segments at the top or bottom of the reflector 221 being also smaller than the radii of curvature of the side curved segments representing part of the transverse curvature of the rear reflecting surface 25 present elsewhere therealong.

The rear reflecting surface 25 of the reflector 21 comprises a plurality of coatings forming a so-termed coldmirror reflecting surface which is protected against damage by a protective coating thereovcr. The coldvmirror reflecting surface is of a type including plural layers of dichroic or two-color vacuum deposited film giving the cold-mirror coating the property of infrared radiation directly therethrough without absorption, while the coldrnirror coating refleets visible light to substantially the same degree as a The protective coating on top of the multi-layer cold-mirror coat- ,ing may comprise a coating of colloidally-suspended Teflon and an epoxy resin, this protective coating being translucent so that light transmitted through the coldmirror reflecting surface on the rear surface 25 of the reflector 21 will be scattered and thereby dispersed.

The shape of the reflector 21 is such that its longitudinal extent is vertically-oriented while its transverse width is horizontally-oriented, the reflector 21 being constructed so as to have a smooth front surface 26 of substantially the same shape as the rear reflecting surface 25 and spaced therefrom in parallel relationship over the extent of the reflector 21. The thickness of the glass comprising the reflector 21 is substantially uniform along the length of the reflector 21, but is somewhat reduced in size at the top and bottom thereof. The reflector 21 is therefore provided with a smooth, continuous, varying countour, rather than including individual flutes on its front surface 26 as is conventional in reflectors used in lighting devices of this character. In effect, the reflector 21 with its continuous varying contour may be said to have an infinite number of flutes inherently present therein. By way of further explanation, the reflector 21 having an infinite number of flutes inherently present therein in accordance with the present invention may be compared to conventional reflectors used in lighting devices of this character and having a predetermined number of physical flutes provided thereon in a manner similar to the manner in which a ramp has been compared to stairs. In this respect, the ramp and stairs have the same general purpose, but the ramp is theoretically characterized as having an infinite number of steps.

The reflector 21 is preferably symmetrical with respect to its optical axis 27 (FIGURE 5) and has a generally rectangular margin when viewed in front elevation (FIG- URE 2). The two longer sides of the reflector 21 appear to be straight when viewing the reflector 21 in front elevation along the optical axis 27. The reflector 21 has an inner focus on its optical axis 27 where a light source is adapted to be disposed and an outer focus at some distance therefrom intersecting the optical axis 27 in perpendicular relation thereto.

A plurality of prisms 39 may be arranged in a band along each of the two longer sides of the reflector 21. Each band of prisms comprises a plurality of generally laterally inwardly extending prisms 30 which are angu larly slanted inwardly in the direction of the transverse or horizontal center-line of the reflector 21, the degree of angularity of each prism increasing as the band of prisms extends outwardly from the horizontal center-line of the reflector 21 on opposite sides thereof. The reflector 21 is supported in the frame 24 which extends forwardly with respect to the opposite side marginal portions thereof and across the top and bottom marginal port-ions thereof to define therewith a cavity of generally concave shape in which the light source 22 is mounted. It will be observed that the bearings 17 previously described as being respectively journaled in the opposite sides of the head swivelly receive the frame 24 at points located forwardly of the reflector 21 and disposed at opposite sides thereof.

In accordance with the present invention, the light source 22 comprises a so-termed Quartz Wing-Tip Light manufactured by the General Electric Company of Schenectady, New York, and generally referred to as a quartzline lamp. Thus, the light source 22 includes an elongated horizontally extending tubular bulb 35 of quartz material having a horizontally-oriented incandescent tungsten filament 36 therein. The filament 36, as more particularly illustrated in FIGURE 4, is formed as a horizontally extending series of coils in which each coil of the series is further defined by a helically extend ing series of coils. The tubular bulb 35 of quartz material in which the filament 36 is disposed is filled with a gaseous mixture including traces of Iodine gas. The quartzline lamp 22 may be generally described as being comparatively small with respect to the power of light intensity produced thereby and is self-cleaning inside and out to retain a high efliciency throughout its life. Its self-cleaning characteristic is a result of its high operating temperature plus the traces of iodine gas in the gaseous mixture filling the bulb 35. The high operating temperature of the quartzline lamp 22 causes dust particles and other foreign matter settling upon the outside of the bulb 35 to be incinerated, thereby keeping the outer surface of the bulb 35 clean. The iodine gas within the bulb 35 accomplishes interior cleaning by causing particles of tungsten burned off the glowing filament 36 to be redeposited thereon. The quartzline lamp 22 is supported by the frame 24 in advance of the reflector 21 so as to dispose the filament 36 at the inner focus of the reflector 21 with the filament 36 being substantially parallel to the horizontal or transverse center-line of the reflector 21 so as to extend across the optical axis 27 of the reflector 21 in perpendicular relation thereto.

A pair of ceramic socket members 37 are disposed at the opposite ends of the quartzline lamp 22 into which the opposite ends of the quartz bulb 35 are inserted to electrically connect the quartzline lamp 22 to the electrical conductors or wires respectively extending into the lighting head 10 through the bearings 17 on opposite sides thereof and connected into the socket members 37. The socket members 37 and the quartzline lamp 22 plugged thereinto are carried by the light shield assembly 23. In this connection, each of the socket members 37 is frietionally mounted within a tubular jacket 38 having a flange 39 extending outwardly from the inner end thereof, and the flange 39 is fixedly secured to a supporting Wall 40 forming part of the light shield assembly 23. The supporting walls 40 of the light shield assembly 23 are disposed at the opposite ends of the quartzline lamp 22. The light shield assemlby 23 comprises a horizontally extending channel-shaped body 42 disposed forwardly of the quartz bulb 35 and including upper and lower legs partially overlying the quartz bulb 35 to completely shield the forwardly disposed portion of the quartz bulb 35 when viewed in front elevation in a direction along the optical axis 27 of the reflector 21. The supporting

Walls

40, 40 to which the ceramic socket members 37 are aflixed through the respective flanges 39 on the tubular jackets 38 are carried by the body 42 of the light shield assembly 23 and additionally provide supports for respective fanblade shaped side deflectors 43 which are secured to the proximally-related surfaces thereof; The side deflectors 43 screen the opposite ends of the quartzline lamp 22 to prevent the emanation of stray light rays from the ends of the quartzline lamp 22 in directions forwardly of the lighting device. The light shield assembly 23 further includes inturned horizontally extending bracket arms 44 won the opposite ends of the channel-shaped body 42, the

bracket arms 44 respectively terminating in rearwardly disposed vertically extending shoulders 45. The light shield assembly 23 including the channel-shaped body 42, the supporting walls 4ft, 40, and the

side deflectors

43, 43 is painted with a temperature-resistant fiat-black paint to prevent the reflection of any stray light from the quartzline lamp 22 by the light shield assembly 23.

Referring to FIGURES 6 and 7, it Will be observed that the frame 24 of the lighting head 10 is provided with a pair of spaced, parallel projections 50 at each of the opposite sides thereof, the respective pairs of projections 50 extending inwardly of the frame 24 and providing trackways for slidably receiving the bracket arms 44 and the shoulders 45 at the opposite ends of the light shield assembly 23. It will therefore be understood that the light shield assembly 23 is slidably movable within the trackways provided by the pairs of inwardly extending projections 50 in order to properly adjust the position of the quartzline lamp 22 carried thereby for positioning the filament 36 at the inner focus of the reflector 21. To this end, the mechanism for adjusting the position of the quartzline lamp 22 carried by the light shield assembly 23 includes a threaded pin 51 rigidly affixed to the shoulder 7' r 45 at each of the opposite ends of the light shield assembly 23, the threaded pin 51 extending through a suitable aperture in the rear of the frame 24 and being threadably received in the threaded bore of a rotatable cap or nut 52. A coiled spring 53 encircles the threaded pin $1, the coiled spring 53 being placed under compression with its opposite ends being seated against the frame 24 and the shoulder 45 of the light shield assembly 23 corresponding thereto. The coiled springs 53, 53 hold the nuts 52, '2 against the frame 24 and bias the light shield assembly 23 forwardly with respect to the frame 24- and the reflector 21 for positioning the quartzline lamp 22 carried by the light shield assembly 23 in a selected adjusted position with tie filament 36 at the inner focus of the reflector 21. Movement of the light shield assembly .23 and the quartzline lamp 22 upon making an adjustment by tightening or loosening the nuts 52, 52 occurs in a direction toward or away from the reflector 21 along the optical axis 27. Minor adjustments of this nature can usually be relied upon to improve the light pattern produced by the lighting device following replacement of the quartzline lamp. f A transverse heat dissipation plate is secured to the frame 24 so as to be positioned forwardly of the light shiled assembly 23 in covering transverse ali'nement therewith. The heat dissipation plate as is convexly curved and is provided with two rows of elongate slots er .disposed along the upper and lower marginal portions thereof, respectively. The convex heat dissipation plate 66 is preferably made of a metal having excellent heat conductivity so as to draw heat from the lighting head in, the rows of elongate slots 61 being provided therein to allow heated air to escape outwardly thereof.

A handle assembly 64 is mounted on theframe 2 2- forwardly of the convex heat dissipation plate 6d, the handle assembly 64 including an intermediate grill portion as and handles 66 extending outwardly from the opposite ends thereof. The intermediate grill portion d5 of the handle assembly 64 extends transversely with respect to the convex heat dissipation plate 6th in forwardly spaced overlying relation thereto. The grill portion 65 of the handle assembly 64 is provided with a plurality of slots 67 for further aiding in the dissipation of heated air from the lighting head 19. f desired, the central area of the intermediate grill portion eSmay be employed as a base for attaching an emblem thereon for decorative and/ or informative purposes. Each of the handles 66 at the rer spective opposite ends of the intermediate grill portion 6.; of the handle assembly 6 comprises upper and lower angularly disposed handle bars which extend forwardly with respect to the lighting'head "all in divergent relationship to define a handle 66 of substantially if-shaped configuration. The lighting head 11 itself will become somewhat warm when the lighting device is in use because of its small size and the relatively high operating temperature of the quartzline lamp 22 utilized as the light source. The V-shaped handles 66 are therefore disposed laterally outwardly with respect to the lighting head 1 in proximity to the respective bearings 17 about which the lighting head 19 may be pivoted with respect to the yoke 16.

A manually-operable switch 7% (FIGURE 5) is interposed in the electrical wiring connecting the quartzline lamp 22 to the source of electric power for varying the intensity of light given off by the quartzline lamp 22 by changing the voltage provided from the transformer upon operation of the switch 70.

In accordance with the present invention, the lighting device provides a controlled beam of light originating from the quartzline lamp 22 and being reflected by the reflector 21 forwardly of the head 16 in a horizontallyoriented light pattern. The prisms at opposite sides of the reflector 21 are instrumental in bending light rays into the horizontally-oriented light pattern which might otherwise stray into the eyes of the patient. In general,

. Barra e o U lying in a plane perpendicular to the optical axis 27 of the reflector 21 and possessing a lateral or horizontal width substantially in excess of the longitudinal or vertical height. In producing the horizontally-oriented light pattern, the'reflector 21 reflects light rays from the quartzline lamp 22 so as to cause crossing of the individual reflected light rays in both directions. Thus, the light reflected from one side of the reflector 21 contributes to the light present in the opposite side of the pattern, while the light reflected from the top of the reflector 21 contributes to the light at the bottom of the light pattern and vice versa. The center area or the area directly bebind the quartzline lamp 22 on the reflector 21 contributes the most reflected light to the horizontally-oriented light pattern, and. progressively decreasing amounts of reflected tional reflector constructions which commonly accept approximately 169 degrees of light from the light source utilized therewith. in the present instance, the construction of the qnartzline lamp 22 with its coiled filament 36 in the form of a horizontal cylinder and the specific shape characteristics of the reflector 21 enable the reflector 21 to be wrapped about the quartzline lamp 22 so as to accept (approximately 3,860" Kelvin) without noticeable heat.

The cold-mirror rear reflecting surface 25 on the reflector 21 transmits yellow, red, and infrared light througlrthe back of the reflector 21, while reflecting the desired li ht to give a properly color balanced light beam (approximately 3800 Kelvin) without noticeable heat.

By way of one specific example of a lighting device constructed in accordance with the present invention which has been found to be eminently satisfactory in use, the reflector 21 has been constructed so as to provide a rear reflecting surface 25 and a forward surface 26 having substantially the shape of a portion of an elliptic paraboloid, as heretofore described, with the particular 7 reflector 21 illustrated in FIGURES 8-10, inclusive, having a horizontal width of 4.5 inches and a vertical height of 1.612 inches. 'A vertical plane perpendicular to the transverse center line of the reflector 21 and in which the longitudinal center line of the reflector 21 lies would intersect the rear reflecting surface 25 along a verticallyoriented curved line forming a portion of an ellipse having a major axis of 39.5 inches and lying along the optical the light pattern may be considered as being concentrated at the outer focus of the reflector 21 with the light pattern axis 27 of the reflector 21, a minor axis of 16.256 inches,

and a distance from the inner focus to the adjacent vertex of the vertically-oriented curved intersection line of 1.75 inches. A horizontal plane perpendicular to the longitudinal center line of the reflector 21 and in which the transverse center line of the reflector 21 lies would intersect the rear reflecting surface 25 along a horizontally-oriented curved line having a central curved segment provided with a radius of curvature of 6 inches measured from a point lying on a line bisecting the horizontally-oriented curved intersection line, the latter bisecting line corresponding to the optical axis 27 of the reflector' 21, and side curved segments on opposite'sides of the central curved segment, each of which is provided with a radius of curvature of 3 inches measured from respective points disposed on opposite sides of the bisecting line and offset 0.375 inch therefrom. The thickness of the glass comprising the reflector 21 as measured along the transverse center line of the reflector 21 is 0.282 inch. At either the top or bottom edge of the reflector 21, the transverse curvature of the rear reflecting surface 25 lies along a substantially vertically-oriented curved line having a central curved segment provided with a radius of curvature of 5.381 inches measured from a point lying on a line bisecting the substantially verticallyoriented curved line, and side curved segments on opposite sides of the central curved segment, each of which is provided with a radius of curvature of 2.781 inches measured from respective points disposed on opposite sides of the latter bisecting line and offset 0.363 inch therefrom. The thickness of the glass comprising the reflector 21 as measured at either the top or bottom edge thereof is 0.27 inch.

The light source for the reflector 21 is a General Electric quartzline lamp bearing the designation 6.6 A/T4Q/CL200W which comprises a tubular iodine-cycle quartzline lamp rated at 200 watts, 6.6 amps, 30.3 volts and operated at 23.0 volts, 6.0 amps, maximum. The rated life of this quartzline lamp at its operating voltage of 23.0 volts exceeds 1800 hours, and the quartzliue lamp possesses the properties of self-cleaning, inside and out, as earlier described, to maintain its lumen output throughout its life.

The transformer 15 steps down the voltage from an electrical outlet having the standard 110l20 volt alternating current to approximately 23.0 volts and its voltage output is controlled by the switch 70 so as to adjust the voltage supplied to the quartzline lamp in order to vary light intensity emanating therefrom. The switch 70 is of a three-position type for adjusting the light intensity emanating from the quartzline lamp 22 and reflected by the reflector 21 to approximately 1,000, 1,500, and 2,000 foot candles at 36 inches from the reflector 21. The color of the light pattern produced by the lighting device is approximately 3800 Kelvin, while the temperature of the light beam at 36 inches from the reflector 21 does not exceed 6 degrees Fahrenheit in excess of the ambient temperature. i

The horizontally-oriented light pattern produced by this specific example of a lighting device in accordance with the present invention is in focus from 30 inches to 42 inches away from the reflector 21 and possesses a horizontal width of approximately 15 inches and a vertical height of approximately 3.5 inches at a distance of about 36 inches away from the reflector 21.

The lighting deviceas constructed in accordance with the foregoing example is extremely eflicient and povides increased illumination of the oral cavity of a person for facilitating dental and surgical procedures. It will be understood, however, that the foregoing example is given for illustrative purposes.

In the drawings and specification there has been set forth a preferredembodiment of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined in the claims.

We claim:

1. A lighting device for illuminating the oral cavity of a person to facilitate dental and surgical procedures, said lighting device comprising:

(a) a light source having a horizontally-oriented filament for providing illumination when energized,

(b) shield means disposed forwardly of said light source in covering relation to said horizontallyoriented filament,

(c) vertically-oriented reflector means disposed behind said light source and extending above and below said light source, and

(d) said vertically-oriented reflector means being substantially in the shape of a portion of an elliptic paraboloid having a vertical height greater than the horizontal width and presenting a concave surface opposed to said horizontally-oriented filament and having an optical axis intersecting said horizontally-oriented filament in perpendicular relation thereto to reflect light emanating from the energized filament of said lightsource in a horizontally-oriented pattern for illumination of the oral cavity of a person.

2. A lighting device for illuminating the oral cavity of a person to facilitate dental and surgical procedures, said lighting device comprising:

(a) a light source having a horizontally-oriented filament for providing illumination when energized, (b) shield means disposed forwardly of said light source in covering relation to said horizontallyoriented filament,

(c) vertically-oriented reflector means disposed behind said light source and extending vertically above and below said light source, said vertically-oriented reflector means having an optical axis extending outwardly thereof in perpendicular relationship to the transverse center-line of said vertically-oriented reflector means,

(d) said horizontally-oriented filament extending transversely with respect to said vertically-oriented reflector means in intersecting perpendicular relation to the optical axis thereof and in parallel spaced relation to the transverse center-line thereof,

(e) said vertically-oriented reflector means being substantially in the shape of a portion of an elliptic paraboloid having a vertical height greater than the horizontal width and with two spaced inner and outer foci along its optical axis and presenting a concave surface opposed to said hirozontally-oriented filament,

(f) the outer focus of said vertically-oriented reflector means being located between the light source and the face of a person whose oral cavity is to be illuminated,

(g) means for adjusting the position of said horizontally-oriented filament in a direction along the optical axis of said vertically-oriented reflector means to dispose said filament at the inner focus of said vertically-oriented reflector means, and

(h) said vertically-oriented reflector means reflecting light emanating from the filament of said light source when energized in a horizontally-oriented pattern for illuminating the oral cavity of a person.

3. A lighting device for illuminating the oral cavity of a person as set forth in claim 2, wherein (i) said filament is carried by said shield means, and

(j) said adjusting means moving said shield means upon actuation thereof to effect adjustment of the position of said filament.

4. A lighting device for illuminating the oralcavity of a person to facilitate dental and surgical procedures,

said lighting device comprising:

(a) a horizontally extending elongated tubular bulb,

(b) a horizontallyoriented filament disposed within said bulb,

(c) means to. electrically energize said filament for illuminating said bulb to provide a light source,

(d) shield means disposed forwardly of said bulb in covering relation thereto,

(e) curved vertically-oriented reflector means disposed behind said bulb and extending vertically above and below said bulb,

(f) said vertically-oriented reflector means being substantially in the shape of a portion of an elliptic paraboloid having a vertical height greater than the horizontal width and presenting a concave surface opposed to said bulb which comprises a longitudinal curvature extending between the upper and lower ends of the reflector means and a transverse curvature extending between the opposite sides of the reflector means, said transverse curvature being of less depth than the depth of the longitudinal curvature, and

(g) said verticall -oriented reflector means having an optical axis intersecting said horizontally-oriented filament in perpendicular relation thereto and reflecting light emanating from said bulb when illuminated by energization of said filament in a horizontallya person.

5. A lighting device for illuminating the oral cavity of a person as set forth in claim 4, wherein (h) said vertically-oriented reflector means extends about said bulb in an arc lying'in a range exceeding 160 and up to and including approximately 240 of the circumference of said tubular bulb.

6, A lighting device for illuminating the oral cavity of a person to facilitate dental and surgical procedures, said lighting device comprising:

(a) a horizontally extending elongated tubular bulb,

(b) a horizontally-oriented filament disposed within said bulb,

() means to electrically energize said filament for illuminating said bulb to provide a light source,

(d) a shield assembly disposed forwardly of said bulb comprising (1)"a body frontally covering the horizontal extent of said bulb, and

(2) a pair of side deflectors mounted on said body in spaced relationship, said side reflectors extending laterally with respect to said body and covering the opposite ends of-said bulb;

(f) said vertically-oriented reflector means being substantially in the shape of a portion of an elliptic paraboloid presentinga concave surface opposed to said bulb which comprises a longitudinalcurvature extending between the upper and lower ends of the reflector means and a transverse curvature extending between the opposite sides of the reflector means, said transverse curvature being of less depth than the depth of the longitudinal curvature, and

(g) said vertically-oriented reflector means having an optical axis intersecting said horizontally-oriented filament in perpendicular relation thereto and reflecting light emanating from said bulb when illuminated by energization of said filament in a horizontallyoriented pattern for illumination of the oral cavity of a person.

7. A lighting device for illuminating the oral cavity of a person to facilitate dental and surgical procedures, i said lighting device comprising:

(a) a horizontally extending elongated tubular bulb of quartz material,

(b) a horizontally-oriented filament having'a horizontally extending series of coils, each coil in said series being defined by a helically extending series of coils, said filament being disposed within said quartz bulb,

(c) a gaseous mixture including iodine gas filling said quartz bulb,

(d) means to electrically energize said filament for illuminating said bulb to provide a light source,

(e) shield means disposed forwardly of said quartz bulb in covering relation thereto,

(f) curved vertically-oriented reflector means disposed behind said quartz bulb and extending vertically above and below said quartz bulb, and 1 (g) said vertically-oriented reflector means being substantially in the shape of a portion of an elliptic paraboloid having a vertical height greater thanthe horizontal width and presenting a concave surface opposed to said quartz bulb and having an optical axis intersecting said horizontally-oriented filament in perpendicular relation thereto to reflect light emanating from said quartz bulb when illuminated by energization of said filament in a horizontally-oriented pattern l2 source in covering relation to said horizontally-oriented filament,

* (c) a composite reflecting-retracting glass member disposed behind said light source and having a vertical height greater than the horizontal width and extending vertically above and below said light source,

(d) said glass member being vertically elongated and having longitudinal and transverse curvatures,

(e) the longitudinal curvature having a depth greater than the depth of the transverse curvature,

(f) said glass memberhaving a rear reflecting surface substantiallyin the shape of a portion of an elliptic paraboloid,

(g) the front surface of said glass member being parallel to the rear reflecting surface thereof and being smooth throughout at least a major portion of its area,

(h) said glass member having an optical axis on which lie spaced inner and outer foci, the inner focus being located substantially at said light source and the outer focus being located between the light source and the face of a person whose oral cavity is to be illuminated,

(i) theoptical axis of said glass member intersecting the horizontally-oriented filament of said light source in perpendicular relation thereto, and

the energized filament of said light source so that the beam of reflected light from said glass member is spread horizontally to 'a' greater extent than its vertical spread to produce a horizontally-oriented light pattern at the outer focus of said glass member for illumination of the oral cavity of the person.

9. A lighting device for illuminating the oral cavity of a person to facilitate dental and surgical procedures, said lighting device comprising: i

(a) a horizontally extending elongated tubular bulb of quartz material,

(b) a horizontally-oriented filament having a horizontally extending series of coils, each coil in said series being defined by a helically extending series of coils,

said filament being disposed within said quartz bulb,

'(c) a gaseous mixture including iodine gas filling said quartz bulb,

, '(d) means to electrically energize'said filament for illuminating said bulb to provide a light source,

, (f) a composite reflecting-refracting glass member disposed behind said quartz bulb and having a vertical height greater than the horizontal width and extending vertically above and below said quartz bulb,

(g) said glass member being vertically elongated and having longitudinal and transverse curvatures,

(h) the longitudinal curvature having a depth greater than the depth of the transverse curvature,

(i) said glass member having a rear reflecting surface substantially in the shape of a portion of an elliptic paraboloid,

(j) the front surface of said glass member being parallel to the rear reflecting surface thereof and being smooth throughout at least a major portion of its area,

(k) said glass member having an optical axis on which lie spaced inner and outer foci, the inner focus being located substantially at said quartz bulb and the outer focus being located between said quartz bulb and the face of a person whose oral cavity is to be illuminated,

- (l) the optical'axis of said glass member intersecting the horizontally-oriented filament disposed within said quartz bulb and being inperpendicular relation to said horizontally-oriented filament, and

(in) said glass member reflecting light emanating from said quartz bulb when illuminated by energization of said filament so that the beam of reflected light from said glass member is spread horizontally to a greater (j) said glass member reflecting light emanating from 13 l4 extent than its vertical spread to produce a horizon- 2,540,417 2/51 Bergmans et a1 2404l.l tally-oriented light pattern at the outer focus of said 2,540,577 2/51 Greppin 24041.15 glass member for illumination of the oral cavity of 2, 00,514 6/52 Mitch u 240-25 the p 2,757,277 7/56 Pennow 240-442 5 i Ref r nces cited y h Examiner fijfi 36$};

UNITED STATES PATENTS 2 2 5 5 1 9 0 Pieper 2404.4 NORTON ANSHER, Primary Examiner- 2,486,558 11/49 Franck .240'25 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 191, 023 June 22, 196

Daryl D. Sullivan et al.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 8, line 33, strike out "(approximately 3,800 Kelvin) without noticeable heat." and insert instead H approximately 240 degrees of light emanating therefrom.

Signed and sealed this 30th day of November 1965.

(SEAL) Atlest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents

Claims

1. A LIGHTING DEVICE FOR ILLUMINATING THE ORAL CAVITY OF A PERSON TO FACILITATE DENTAL AND SURGICAL PROCEDURES, SAID LIGHTING DEVICE COMPRISING: (A) A LIGHT SOURCE HAVING A HORIZONTALLY-ORIENTED FILAMENT FOR PROVIDING ILLUMINATION WHEN ENERGIZED, (B) SHIELD MEANS DISPOSED FORWARDLY OF SAID LIGHT SOURCE IN COVERING RELATION TO SAID HORIZONTALLYORIENTED FILAMENT, (C) VERTICALLY-ORIENTED REFLECTOR MEANS DISPOSED BEHIND SAID LIGHT SOURCE AND EXTENDING ABOVE AND BELOW SAID LIGHT SOURCE, AND (D) SAID VERTICALLY-ORIENTED RELFECTOR MEANS BEING SUBSTANTIALLY IN THE SHAPE OF A PORTION OF AN ELLIPTIC PARABOLOID HAVING A VERTICAL HEIGHT GREATER THAN THE HORIZONTAL WIDTH AND PRESENTING A CONCAVE SURFACE OPPOSED TO SAID HORIZONTALLY-ORIENTED FILAMENT AND HAVING AN OPTICAL AXIS INTERSECTING SAID HORIZONTALLY-ORIENTED FILAMENT IN PERPENDICULAR RELATION THERETO TO REFLECT LIGHT EMANATING FROM THE ENERGIZED FILAMENT OF SAID LIGHT SOURCE IN A HORIZONTALLY-ORIENTED PATTERN FOR ILLUMINATION OF THE ORAL CAVITY OF A PERSON.