US1596370A - Surgeon's lamp - Google Patents

Description

Aug. 17 1926. Y

A P. A. NIRDLNGER sURGEoNs LAMP Filed Nov. 50, 1921 5 Sheets-Sheet 1 Aug. 17 1926. v 1,596,370

P. A. NIRDLINGER sURGEoN's LAMP Aug. 17 1926. 1 1 1,596,370

P. A. NIRDLINGER SURGEON S LAMP 5 sheets-sheet 4 1111EA Nov. 5o, V1921 @55% gzal, @ffm/www Hy 17%@ 0 7 5 907 .t 6 e 9 m 5, q.. 1 e. M ./,V m m im M NA, ULO Dwz RN. f 10W NmN Awww R m a j wm 8 1 7 1 ...W D v g 4 Au m ff fw Patented Aug. 17, 1926.

UNITED STATES 1,596,370 PATENT OFFICE.

PATRICK A. NIRDLINGER, F CHICAGO, ILLINOIS.

SURGEONS LAMP.

Application led November 30, 1921. Serial No. 518,816.

This invention relates to illuminating units especially applicable to operatingA shall be of improved construction, eiiicientA in operation and convenient. to manipulate.

The invention is exemplified in the combination and arrangement of parts shown in the accompanying drawings and described in the following specification, and it is more specifically pointed out in the appended claims. l

Fig. 1 is an elevation of 4one embodiment of the present invention.'

Fig. 2 is a vertical section of the support for the mechanism shown in Fig. 1.

Fig. 3 is a top plan view of the mechanism shown in Fig. 1, Without the exterior light. A

Fig. 4 is Aa top plan view of the illuminating unit on a larger scale than that of Fig. 3.

Fig. 5 is an elevation of the illuminating unit shown in Fig. 4.

Fig. 6 is a vertical sectional view of the illuminating unit.

Fig. 7 is a sectional view of one of the beam projectors comprised inthe unit.

Fig. 8 is an elevation of a slightly modified form of the support.

Fig. 9 is a vertical section of the support forming part of the device shown in Fig. 8.

Fig. 10 is an elevation of a further modilication.

Fig. 11 is a fragmentary plan of the device o Fig. 10.

During the performance of surgical operations it is very desirable that an abundance of white light shall be directed upon or into the part or parts subjected to the operation and that this light shall emanate from separate sources to avoid the' formation of deep shadows. It is also important that the source of the light shall be positioned and arranged to prevent annoyance to the operator or patient from glare of the light or from heat radiating from the light sources and at the same time be adjustable to permit radiated heat from the source to strike the patient in case this is desirable. Certainty and ease of manipulation are .also very desirable in a device of this nature. The present invention is so designed and the parts so combined that the above and other desirable characteristics are secured, producing an illuminating unit which has proved eminently successful for surgical and like operations.

As shown in Fig. 1 of the drawings, an upright hollow support or pedestal 10 is provided With a low laterally extending baseA 11, which is supported on casters 12 to permit ease of movement of the illuminating unit to any desired position in the operating room. T e support 11 carries van underhung socket 13 to which the pedestal 10 is secured sothat the weight of the device is kept low as possible to' prevent any danger of overturning. Within the pedestal 10 is slidably mounted a standard 14, which extends upwardly through an opening in the ap at the top of the pedestal. The cap 15 is rotatably supported on the pedestal 10 and is provided with a rod 15 threaded through the flange of the cap and extending' through a horizontal slot in the upper end of the pedestal. The inner end of the rod 15 carries a .shoe15 foi` engaging the standard 14 and locking the standard and cap against relative movement. When so locked the attendant may use the rod 15 as a handle for rotating the standard and parts carried thereby. Within the pedestal 10 is a counterweight 16, having a central opening of suflicient size to permit the lower end of the standard 14 to project downwardly into or through the counterweight. The counterweight 16 is provided with pulleys 17 through which a cable 18 is threaded. The cable 18 has its two ends secured to the cap 15, and the middle portion of the cable passes through an opening in the standard 14 and over a sheave 19 journaled in the opening. This arrangement gives a two-to-one movement of the standard 14 relative to thecounterweight 16, and when the standard is in lits uppermost position, which is the usual operating position, the counterweight 16 will rest on the bottom of the underhung socket 13, thus bringing the weight very near to the floor and providing greater stability for the supporting frame. The couuterweight 16 is free to rotate in the pedestal 10 when the standard 14 and cap 15 are rotated b v the handle 15". In cases where less height of adjustment of the standard 14 is sufficient the standard and counterweight may be connected for one to one relative movement. Where this ar'- rangement is followed the sizeof the councollar 28 to hold the pinion 27 in fitting 20 at the opposite side to the gearv fitting 20.

terweight can be correspondingly reduced. The standard 14 may be made of metal piping or other suitable materiah and is provided with a fitting 20 at its upper end, through which a horizontal arm 21 extends and in which it is slidably supported. projecting portion 22 of the arm 21 carries a weight 23for counterbalancing the illuminating unit carried by the arm 21. The arm 21 is held in adjusted positions inthe fitting 20 by set screws or other suitable means. Slidably mounted in the arm 21 is a rod or bar 24 having bifurcations 25 at its outer part on which is pivotally mounted the illuminating unit 26. The bar is provided with a bevel pinion 27 having an integral collar 28 provided with a set-screw 29, by which the pinion may be adustably fixed to the bar 24. A bracket 3() is secured to the end of the arm 21 and engages the position adjacent the end of the arm 21. The bar 24 may be adjusted longitudinally in the arm 21 by loosening the set-screw 29 and sliding the bar through the collar 28. Journaled on the bracket 30 in position to mesh with the pinion 27 is a bevel gear 31 lhaving an arml 32 secured thereto and extending upwardly. therefrom. An extensible rod or pipe 33 connects the upper end of the arm 32 with an. arm 34 carried by the pinion journaled on a stud shaft supported by the A worm 36 meshes with the pinion 35 and is provided with a downwardly extending operating shaft 37 journaled 4in a bracket 38 on the standard 14. The lower end of the shaft 37 is provided with a hand wheel39, by which it may be conveniently rotated by the operator. Rotation of the hand wheel 39 will be transmitted through the mechanism described, to the collar 28 and the rod 24, which in turn will shift the forks 25 and tilt the illuminat-j ing unit 26 about a horizontal axis to direct the rays from the unit as will hereinafter appear.

The worm. 36 will lock the illuminating unit in any position in which it is tilted by the hand wheel 39.

The upper end of the illuminating unit 26 is provided with a bracket 40, to which 1s pivotally secured an extension rod or pipe 41 having the opposite end thereof pivotally connected to an arm 42 projecting upwardly from the gear 43 mounted on the 35. A worm 44 meshes with the gear 43 and is provided with an operating rod 45 similar to the rod 37. A hand wheel 46 is connected with the rod 45 and preferably is positioned below the hand wheel 39 to prevent confusion of the operator in manipulatingthe two hand wheels. Rotation of the hand wheel 46 w1l1 tilt the unit 26 about its pivotal connection with the .forks 25 and v53 clamps Vthe lamp filament 62.

upon an axis at right angles to the tilting movement produced by rotation of the hand wheel 39. The illuminating unit will be held in its various 4adjusted positions by the worm 44. A set-screw 47 is provided to per- A mit extension of the rod 41 to conform to various `positions of the rod 24 in the arm 21. The rod 24 can be extended to bring the illuminating unit to the center of various sizedrooins and when this -is done the arm 21 canbe adjusted in the fitting 20 to maintain a perfect balance of the device. It should be noted that the hand wheels 39. and

46 are suliciently removed from the illum1' nating unit to permit their operation by persons outside of the immediate vicinity of the operating table. This permits the manipulation of the light by an attendant without danger of bringing infection to the patient or to those direztly occupied in the operation.

The construction of the illuminating unitwill be best understood from Figs. 4 to 7 inclusive. This unit comprises a hollow cylindrical housing 48 having a cover 49. The bracket 40 is provided with a rod 50, which extends through the cover 49 and carries a fastener 51 by which the rod may be adjustably secured to the wall of the housing 48. A set-screw v52 projects through a-slot in the wall of the housing for clamping the fastener 51 in adjusted positions. The rod 50 is bent laterally near its center and provided with -a strap 53 to form a circular eye for receiving alamp. socket 54. This vsocket passes of the housing 48 and carries a slide 56 for closing the slot 55, the slide 56 being held by guide members 57 Figs. 4 and 6. The strap the lamp socket 54 sufliciently tight to hold the socket in various positions to which it may be moved either in the direction of the axis of the socket or in different angular positions of rotation. The vertical position of the lamp inthe housing 48 may be adjusted by loosening the setscrew 52 and moving the vrod 50 vertically relative to the housing. An arm 58 is adjustably secured to the rod by a set-screw 59, and slidably mounted on the arm 58 is a bracket 60 which carries a reflector 61 fur directing the rays of light downwardly from be adjusted along the rod 58 and held 1n its various positions by a set-screw 62 and it may also be adjusted to various A from the filament 62 by movement of the set-screw 59. The reflector 61 comprises a plano-convex lens having its convex surface silvered as shown at 63. A concavo convex, parabolic, or other shape of lens may of course be used in a similar way for forming a refiector where such other shape of reflec-I tor is desired. The lens is supported in a socket member 64, carried by the bracket The reector 61 may.

distances through a slot 55 in the wall 60 so that the concave side of the silver coating is adjacent the filament 62, thus providing a concave reflector for the lamp. The rays of light emanating downwardly from the filament 62 pass through the planoconvex lens 65,` which brings the rays in substantial parallelism and directs them downwardly in a cylindrical beam.' A conical shaped member 66 is detachably secured to the lower' end of the casing 48 by bayonet sockets 67, Fig. 5, by which the size of the beam or field ofv light may be readily varied or controlled.

On a level with the lamp filament the housing 48 is provided with a plurality of laterally extending tubes 69. These tubes may vary in number and are arranged in diametrically opposite pairs as shown in Fig. 4. It will be noted that the tubes are all positioned on substantially two opposite sides of the housing, leaving the other two sides of the housing closed. This is for the purpose of preventing rays from being emitted from the sides ofthe housing, which are ordinarily above the sides of the operating table where the attendants stand. By having all of the rays in substantially the plane of the table, and none coming from the sides thereof, there is less danger of shadows being formed which would obstruct the vision of the surgeon. The tubes are provided with telescoping lens carriers 70, which are locked in adjusted positions by i set-screw 71 and one of which is shown in section in Fig. 7. Each carrier is pro-` vided with a lens 72 of plano-convex form and also with a filtering screen 73 supported on spring clips'74. The filteringv screen 73 may be made of glass of a suitably selected color to filter out any undesirable rays from the lamp- 62. With a nitrogen globe a suitably selected blue colored screen will give a substantially white light. The lenses 72 will deflect the rays so as to produce beams which are directed from the lenses 72 against a series of reflecting mirrors 75, adj ustably supported on arms 76 carried by the housing 48. A mirror is provided for each tube 69 and may be held in any adjusted position by a set-screw 77 for reflecting the beam of light from its tube in the desired direction. By setting the various mirrors 75 so that all of the beams from the tubes 69 will meet the beam from the casing 48 at a common location a flood of light may be secured at any desired position so that the locality where the beams meet will be illuminated by rays from a number of different directions, thus providing an abundance of light and the absence of deep shadows. The size of the Ybeams from the mirrors may be adjusted by shifting the lenses 72 so that all beams falling on the common field will be of substantially uniform size. This adjustment of the lenses together with the removable member 66 permits adjustment of the size of the illuminated field as occasion may require. Itshould be noted that the field in which the beams meet is below the locality into which region of best 'illumination into the desired -position for properly illuminating the area for the various operations. It will be seen that the light may be readily raised or lowered by pushing up or down on any of the parts connected with the standard 14 and that it may be tilted to any desired angle and held in these positions by rotating the hand wheels 39 and 46. These manipulations may be made by an attendant at a distance from the operating table without danger of contamination, the practically universal adjustment of the light secured permitting complete illumination in thev proper position for practically any operation that the surgeon may wish to perform. The overlapping of the beams from the various directions will intermingle the rays so that any tendency to chromatic separation or the colors will be overcome by the overlapping of' the beams from the various projectors.

In order to intercept falling dust Tor other foreign matter a glass shield 78 may be suspended beneath the illuminating unit by rods 79 supported by the bars 76. It will be noted that the opposite position of the tubes 69 will bring the lenses 72 diametrically opposite one another so that any rays reflected from their inner surfaces will be re-directed backwardly through the housing and unite with the rays emanating from the original source of light. This will effect a considerable saving in light for the reason that approximately ten per cent ofthe light which strikes a lens is reflected from the surface and not transmitted.

In some operating roomsv it is not convenient to provide space for a standard and counterbalance like that shown in Fig. 3. In places of this kind anarrangement similar to that shown in Fig. 8 may be employed. In that figure a pedestal 8O is provided with supporting rollers 81 and an upwardly projecting frame 82 having rollers 83 arranged to travel in a track 84 secured to the wall. This will permit the standard to be located adjacent the wall of the building and to be. moved along the room parallel with the wall.

.housing 48 and a globe roughened or other In place of the standard 14 a curved rod or bar 85 may be provided, having its vertical portion 86 arranged to slide up and down in the pedestal 80 and having a horizontal arm 87 for supporting the illuminating unit in a manner similar to the arm 2l in the forni of the device previously described. A cable 88 passes over a pulley 89 on the frame `824 and a pulley 90 on the counterweight 91. The end of the cable is then attached to the cap 92 for the pedestal 80. This will permit vertical movement of the arm 87 under control. of the counterweight 91, there being a relative tWo-to-one movement of the arm and counterweight. The outer end of the arm 87 is supported by a cable 93 passing over a pulley 94 on the frame 82 and having its lower end secured directly at 95 to the counterweight 91. The tact that the cable 93 extends at an angle from the frame 82 retains the cable '93 substantially taut for a limited movement of the arm 87 With a direct connection of the cable to the weight 91, although the vertical movement of the arm is twice that of the Weight. Gear wheels 96 and hand Wheels 97 are provided for tilting the illuminating unit in the manner previously desc-ribed. y

Where the invention is used in a room .having no other source of general illumination it may be desirable to provide an additional light globe as shown in Figs. 10 and 11. For this purpose a socket 98 having a bulb 99 is secured to the top of the 100 encases the bulb. The globe may be made of glass having a suitable surface for diffusing the light.A The socket 98 is preferably on a separate circuit 101 so that in case of accident to the light circuit for the main unit the light of the bulb 99 will not be affected. If the main unit should fail the casing 48 can be inverted so that the Ibulb 99 will supply sufliced light to enable the surgeon to care'for the patient until the difticulty 1s remedied. -This additional source 'of light is also shown in Figure 1 as applied to the form of device illustrated in that tigure. The unit illustrated in Figure 1, as Well as that of Figures 1() and 11, may be readily inverted by rotating the bar 24 in the arm 21, the arm or bearing. It will be understood, of course,

. that in the device sho-Wn in Figure 8, the arm 87 serves as the axis for rotative movement of the bar 24. The two circuits are con-` trolled separately by a vswitch or switches in reach of the attendant. The rod 41' by which the housing 48 is tilted is in this case bent laterally and connected to the sideof the casing 48 by a bolt 102.

I claim:

1. In a device of the class described., an illuminating vunit and a support for said unit including a pedestal, a standard verti- 'the pedestal for 21 serving as an axis cally movable in the pedestal, a horizontal arm upon which the unit is mounted extending from said standard, the illuminating unit being positioned substantially over the field to be illuminated, and means at rotating the standard and thereby moving the unit bodily in a curvilinear path about the pedestal as an axis, said means having a member adapted to lock the standard against vertical movement.

2. In a' device of the class described, an illaminating unit. and a support for said unit including a pedestal, a horizontal armupon which the .unit is mounted extending from said pedestal, the illuminating unit being positioned substantially above the field to be illuminated, manually operable means at the pedestal for bodily moving the entire unit, said means being adapted to lock the device in its various positions of adjustment, and manually and independently operable means at the pedestal for tilting the' unit about a plurality of angularly .related axes.

3. r1`he combination with an illuminating unit, of a horizontal arm for supporting said unit substantially over a ield to be illaminated, and a pedestal support for said arm comprising means for bodily adjusting the arm vertically to various heights above said lield and adapted to lock the arm in any selected position of adjustment, and a counter-balancing weight on the opposite side of said pedestal support from the unit for retaining the arm in substantially horizontal position and balancing said support.

4. The combination with an illuminating unit, of a horizontally extending arm for supporting the unit substantially above the field to be illuminated, a support for said arm, means for vertically adjusting the arm on said support, the illuminating unit being adjustable longitudinally of the army to- Ward and from the support and a counter balancing Weight on the arm on the opposite side of the support from the unit and adjustable toward and from the support in aecordance withthe adjustment of the unit longitudinally ot the arm.

5. The combination with an illuminating unit, of a. horizontally extending arm for supporting the unit substantially above the field to be illuminated, a supporting pedestal for said arm, means for vertically adjusting the arm on said support, the illuminating unit being adjustable longitudinally of the arm toward and from the supwith an illuminating of a support therefor comprisingl a pedestal, a base for said pedestal, an

underhung socket on said base into which the pedestal opens, a vertically adjustable standard in said'pedestal, a counterweight for the standard operatively connected to the same and arranged to rest in said underhung socket when the standard is raised,

, thereby balancing the pedestal.

7. The combination with an illuminating device, of a support therefor comprising a horizontally extending arm, means for counterbalancing said arm to retain said arm in its horizontal position, a standard for supporting said arm, a hollovs7 pedestal in which said standard is vertically .movable, a counter-balancing weight located within said standard, mot-.ion multiplying mechanism connecting said weight and standard, means positioned adjacent said standard for tilting said device upon its support to various positions of adjustment, and one-way motion transmitting mechanism for locking said device in its various positions of adjustment.

8.'In a device of the class described, an illuminating unit and a support for said unit adapted to position the same substantially over the field to be illuminated including a hollow pedestal, a standard vertically movable in said pedestal, a counter- Weight for the standard within the pedestal, means for connecting the standard to the counterweight, a horizontal arm carried by the standard and upon which the illuminating unit is adjustably mounted, and manually operable means at the pedestal for tilting the unit and for retaining the latter in adjusted position.

9. In a device of the class described, an illuminating unit and a support for said unit adapted to position the same substantially over the field to be illuminated including a hollow pedestal, a standard vertically movable in said pedestal, a counterweight for the standard within the pedestal, means for connecting the standard to the counterweight, said counterweight being hollow and receiving the standard, a horizontal arm carried by the standard and upon which the illuminating unit is adjustably mounted, and means at the pedestal for tilting the unit upon the arm and for retaining the latter in adjusted position.

10. In a device of the class described, an'

illuminating unit and a support for said unit adapted to position thesame substantially over the field to be illuminated including a hollow pedestal, a standard vertically movable in said pedestal, a counterweight for the standard within the pedestal, means for connecting the standard to the counterweight, a horizontal arm carried by the standard and upon which theilluminating unit is adjustably mounted, `means at the pedestal for tilting the unit in retainingthe latter in adjusted position, and means on the pedestal for rotating the standard, said last mentioned means serving also to lock the standard @against vertical movement.

11. A device of the class described comprising an illuminating unit including a casing, a source of light within the casing, at least two independent lenses positioned on two substantially opposite sides of said source in the paths of' the light and-arranged to project a plurality of beams in opposite directions horizontally through the casing, the other two sides of the casing in the same horizontal plane being closed to prevent the emission of rays therefrom means adjacent the casing for bending and reflecting the beams projected by said lenses upon a common field, and a support for said unit adapted to position the same substantially above said field.

12. A device of the class described comprising an illuminating unit including a casing, a source of light within the casing, a plurality of adjacent apertures in said casing in each of two substantially opposite sides of the same, the other two sides of the casing in the same horizontal plane being closed. to prevent the emission of rays therefrom, lenses positioned over said openings, means for bending and reflecting the beams projected lby said lenses upon a common field, and a support for said unit adapted to position the same substantially-.above said field.

1 3. An illuminating device of the class described comprising an illuminating unit having a casing, a source of light within 'said casing, means for projecting a pluralcommon field, means for supporting said illuminating devices substantially above and over a table to be illuminated, means for vertically adjusting said devices to c'ontrol the temperature effect of said device upon the illuminated field of the surrounding region, said adjusting means being positioned a substantial distance horizont-ally from said field, and means for focusing said beams.

14:. An illuminating device of the class described comprising a casing, a source of light within said casing, a plurality of lateral openings in said casing whereby beams are projected laterally from said source of light through said openings, means for bending and reflecting said beams from separated sources upon a common field, and

, arated sources upon a 15. An illuminating device of the class described comprising a casing, a sourceof light Within said casing, a plurality of lateral openings in said casing whereby beams are projected laterally from said source of light through said openings, means or bending and reflecting said beams from sepcommon field, a support for said device adapted to support the same substantially above and over the field to be illuminated, and an imperforate glass late interposed between the said device and the field to in tercept particles of foreign matter that might fallinto the illuminated ield. i y

' 16. An illuminating unit comprising a casing, an initial source of light within said casing, means for projecting'a plurality of beams from said source in substantially opposite directions, means for bend- -ing and directing said beams from separated points upon a common field, and a separate source of light from the exterior of said casing adapted to provide general illumination.

17. An illuminating unit comprising a casing, a source of light within said casing, means for projecting a plurality of' beams from said source in substantially opposite directions, means for bending and directing said beams from separated sources upon a common field, and a separate source ot light upon the exterior of said casing adapted to provide general illumination, said means being adapted to receive current from a circuitseparate and distinct from the circuit of the source of light Within said casing.

18. An illuminating unit comprising `a casing, a source of light Within said casing, means for projecting a plurality of beams from said source in substantially opposite directions, means for bending and directing said beams from separated sources upon a common field, a separate source of light upon the exterior of said casing adapted to provide general illumination, and' means for -bringing said source of general illumination in position to illuminate the area subjected to special illumination by said beams.

19. In combination an.illuminating unit having means therein for projecting a beam of light, a source of general illumination carried on said housing opposite said' beam, and means for inverting said housing to bring the source of general illumination into position to illuminate the area subjected to special illumination by the projected beam.

. 20. In combination an illuminating unit having a source of light and means for pro- 'ecting a beam from said lsource on an area to be subjected to special illumination, a separate source of general illumination, separate means for controlling the supply of energy to said sources, and means for moving said unit to direct lightfrom'the source of generalillumination upon the field for special illumination.

21. In a deviceof the class described and in combination, an illuminating unit comprising a casing, a source of light within said casing, lateral openings in said casing permitting the transmission of separate beams from said source of light, means ior bending and directing said beams on to a common field; and a support for said unit comprising a substantially horizontal arm, a verticaly standard Jfor said arm, means for bodily adjusting said unit rectilinearly toward and from the standard and in a curvilinear path about the standard, said adjusting means being spaced a substantial distance horizontally from said illuminated field, yand additional means adjacent the standard for tilting said illuminating unit upon said arm.

22. In a device of the class described and in combination, an illuminating unit comprising a casing, a source of light Within said casing, lateral openings in said casinfr permitting the transmission of separate earns from said source of light, means for bending and directing said beams on to a common field; and a support for said unit comprising a substantially horizontal arm, a vertical standard for said arm, means for bodily adjusting said unit rectilinearly toward and from the standard and about the standard, said adjusting means being spaced a substantial distance horizontally from said illuminated field, and additional means adjacent the standard for tilting said illuminating unit about a plurality of axes upon said arm, one of said axes being horizontal.

'23. In a device of the class described and in combination,an illuminating unitcomprising a casing, a source of light within said casing, lateral openings in said casing permitting the transmission of separate beams from said source of light, means for bending and directing said beams on to a common field; and a support for said unit comprising a substantially horizontal arm, a vertical standard for said arm, means for bodily adjusting said unit rectilinearly to- Ward and from the standard and in a curvilinear path about thestandard, said adjusting means being spaced a substantial distance horizontally from said illuminated field, and additional means for' tilting said illuminated unit about a plurality oi horizontal axes upon said arm.

24. In a device of the class described and in combination, an illuminating unit comprising a source of light, means for projecting a plurality of beams substantially radially and in a horizontal plane from said source, means for bending and directing said beams from separated points on to a common in a curvilinear path.

field and a support for said unit comprising a substantially horizontal arm, a standard for said arms, and manually engageable means adjacent the standard for tilting said unit about an axis of said arm, and about a horizontal axis at an angle to said rst mentioned axis.

25. In a device of the class described and in combination, an illuminating unit comprising a source of light, means for projecting a plurality of beams substantially radially and in a horizontal plane from said source, means for bending and directing said beams from separated points on to a common field; and a support for said unit comprising a substantially horizontal arm, a vertically adjustable standard for said arm, and manually engageable devices adjacent the standard for tilting said unit about an axis which substantially coincides with the axis of said arm, and about a horizontal axis at an angle to said first mentioned axis.

In testimony whereof I have signed by name to this specification on this 23rd day of November,'A. D. 1921.

PATRICK A. NIRDLINGER

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