US2144526A - Beam changer for incandescent searchlights - Google Patents

Description

Jam 17, 1939; w. J. DAY ,5

BEAM CHANGER F'OR INCANDESCENT SEARCHLIGHTS I Filed Nov, 26, 1957 2 Sheets-Sheet 1 Niven-tor: Wirwtertom J. Day,

His Attorney- Jan. 17, 1939. w, J Y 2,144,526

BEAM CHANGER FOR INQANDESCENT SEARCHLIGHTS Filed Nov. 26, 1937 2 Sheets-Sheet 2 Inventor:

Winte r con I Day;

Atto rnegn Patented Jan. 17, 1939 UNITED STATES PATENT OFFICE BEAM CHANGER FORINC-ANDESCENT SEARCHLIGHTS New York Application November 26, 1937, Serial No. 176,770

6 Claims.

My invention relates to lamp positioning devices, and more particularly to lamp positioning devices in projectors in which the characteristic of the beam is changed responsive to changes in position of the lamp.

One object of my invention is to provide a simple device responsive to successive energizations of the lamp for sequentially positioning said lamp at a plurality of predetermined operating positions without injury to the lamp.

For a better understanding of my invention together with other and further objects thereof, reference is had to the following description taken in connection with the accompanying drawings, and its scope will be pointed out in the appended claims.

In the accompanying drawings, Fig. 1 is a front elevation in perspective of a lamp and positioning device built in accordance with my invention; Fig. 2 is a sectional view of the device; and Figs. 3, 4, 5 and 6 are diagrammatic views illustrating the lamp in its several positions respectively.

Referring to the drawings in detail, Fig. 1 discloses a lamp l mounted in a socket II. The socket is attached to a bracket 12 which is mounted on the end of a shaft, Ill. The shaft is pivoted in a block of insulating material M. and in a base plate l which is preferably of a non-magnetic metal. This shaft carries an armature l6 rigidly attached to the shaft, and a second armature ii movable relatively to the shaft between two positions and being held in either position by a friction device. The armature I6 is held in an intermediate position between two field poles l8 and I9 by a spring 20. The field poles lil and l9 are respectively attached to the end of a magnet coil 2| by a bolt 22.

As stated above, the armature I6 is held in an intermediate position between the field poles l8 and l 9 by a spring 28. This spring is an ordinary helical spring wound about the shaft 13 and having its ends engaging opposite sides of a stationary pin 23. A pin 24 attached to the armature is is positioned between the ends of the spring beyond the pin 23 so that when it moves in either direction, it carries with it one end of the spring while the other end is held stationary by the pin 23, thereby placing the spring under an increased tension and providing aforce to return the armature to its normal position when the field coil is deenergized. The armature l 6 is an elongated magnetic metal member which is, as stated above, normally held in an intermediate position between the field poles l8 and 19. This intermediate position is the position at which the armature is parallel to the field poles. When the magnet coil is energized and the field poles, as a result of this energization, tend to attract the armature so as to establish a low resistance magnetic path, the force exerted upon the armature itself is such that no torque is exerted thereon. For the purpose of providing such torque, the second and movable armature I7 is provided. This movable armature H is also an elongated metallic member, preferably of soft iron, having its ends slightly broadened. It is arranged to have its axis at an angle to the axis of the armature l6. For this purpose, pins 25 and 26 are provided at one end of the armature and spaced from each other sufficiently to permit a substantial angular movement of the armature ll relatively to the armature Hi. In order to keep the armature in any position to which it is moved, a friction device comprising a spring 21 adjustable by a set screw 28 is provided in the armature IT to exert pressure against the shaft I3. When this armature is moved to its one extreme position, determined by pin 25 which engages the armature 16, for example, the angular relationship between the two armatures is such that the pin end of the armature ll will be nearer to the field pole I9 and will be attracted thereby and the other end will be nearer to and will be attracted by the pole l8, thereby providing a clockwise movement of the armatures upon the energization of the magnet 2i. If under these conditions the same relative position of the second armature were maintained,. the armature H, and consequently, the shaft i3 would be successively moved clockwise at each energization of the magnet 2|. In order to provide for an opposite movement of the shaft l3. however, the armature I! is further provided with a leaf spring 38 which engages a pin 31 on the field pole l9 when the armature I6 is attracted to its extreme position. This engagement of the leaf spring 30 with the pin 3! then holds the armature ll while armature l6 moves to its operating position so that it will change its relativeposition to the armature l6 until the pin 26 engages this armature. Upon deenergization of the magnet coil 2| and a return of the armatures to normal position, the pin end of the armature I! will be nearer to the field pole l8, and upon reenergization of the coil 21, a torque willbe exerted by the field poles to move the armatures l6 and H counterclockwise. A pin 32 is provided on this field pole l8 similar to the pin 3| on pole 19 for again changing the angular relationship between the armatures, and therefore upon reenergization of the coil 2|, the armatures will be moved clockwise to their first position.

In Fig. 2, the base 33 of the lamp I0 is illustrated above the socket II which is arranged to clamp the two prongs 34 and 35 of this base. The socket includes a block 36 of insulating material mounted on the end of the bracket I2 which supports two V- blocks 31 and 38 spaced from each other to correspond to the spacing of the prongs 34 and 35. These V-blocks are attached to the insulating block in any convenient manner, for example, by means of studs (not shown) projecting through the block 36. Strips 39 and 40 of sheet metal are clamped respectively at one end under the V-blocks and are folded over the side of the blocks to the front thereof and are there attached to opposite sides of an insulating block 4|. This insulating block is held in spaced relation to the v-blooksby the resiliency of the strips which are preferably of hard copper but may be moved towards the blocks by a thumb nut 42 threaded on a stud 43 mounted in the block 36 and projecting through the block 4!. By turning this nut, the block is moved inwardly, moving the strips towards the V-blocks and clamping the prongs of the lamp in position in the notches of the V-blocks.

Current is carried to the V-blocks by terminal strips 44 and 45, also attached at one end under the V-blocks respectively, and terminating at the respective other ends in contacts 46 and 4! arranged above one another and above the end of the shaft l3 on the axis of the latter. Cooperating contacts 48 and 49 carry current to these contacts through conductors 50 and 5| and through a switch 52 from any convenient source 53. The coil 2| is connected to the conductors 50 and 5|, and is therefore simultaneously energized with the socket contacts when the switch 52 is closed.

In Figs. 3, 4, 5, and 6, a plan view, partly; diagrammatic, of the relationship of the field poles, armatures, and the lamp socket is illustrated in a complete operating sequence. In Fig. 3, the socket is shown in its normal position in which it is held by the spring 20. In this position the socket is in perpendicular relation to a reflector 54. The prongs of the lamp are also held in spaced relation to the axis of rotation, thereby throwing the weight of the lamp off center. In order to compensate for this, a counter weight 55 (see Figs. 1 and 2) is attached to the bracket l2. The armatures l6 and I! in this Fig. 3 are in such relation that the armature I6 is parallel to the field poles l8 and I9, and the armature I1 is turned counter-clockwise thereof, so that its pin end projects towards the field pole l8 and its and an energization of the coil 2 I.

opposite end toward the field pole l9, thereby creating a torque, as indicated by the arrow, tending to turn the assembly in a counter-clockwise direction.

Fig. 4 discloses the position of the armatures and socket resulting from a closure of switch 52 The armature l6 has turned counter-clockwise from the position shown in Fig. 3, and is in the position of the least magnetic resistance path, in which it is held as long as the coil 2| is energized. The armature H has, however, turned to its second position in the clockwise direction of the armature 16 by action of the spring 30 engaging the pin 32 on the field pole I8. The socket in this figure is parallel to the reflector 54, and is spaced between the shaft l3 and the mirror. In this position, the lamp I0 is in its first operating position with its filament 56 in focus with this reflector, and therefore, in position to throw a concentrated or narrow beam. The filament 56 is arranged in a plane and in this position, the plane is perpendicular to the axis of the reflector, thereby presenting its maximum area to the reflector.

Fig. 5 discloses the position of the armature and socket immediately following deenergization of the coil 2| subsequent to the energization disclosed in Fig. 4. In this figure, the socket II has returned to its normal position as illustrated in Fig. 3, but the relationship of the armatures l6 and I! has changed from that illustrated in Fig. 3, so that the pin end of the armature now is nearer to field pole l9, and the opposite end of this armature is nearer to the field pole l8, thereby tending to rotate the armature clockwise, as indicated by the arrow, upon the reenergization of the coil 2|.

Fig. 6 illustrates the position of the armatures as a result of an energization of the coil 2| subsequent to a positioning of the armatures as illustrated in Fig. 5. In this position, the spring 35 has engaged a pin 3| on the field pole l9, and has again returned the armature I! to that position shown in Fig. 3. The socket in this instance holds the prongs of the lamp on the outside of the shaft I 3; that is, the side opposite to the mirror, and thereby holds the lamp in its second operating position with its filament out of focus of the reflector. In this position, the light from the reflector is scattered, and a broad beam is projected by the mirror.

One important advantage of this device, is that of the spring 20, a gradual increase in the torque of the spring is obtained, and when the spring 30 touches the pins 31 and 32, it is also placed under strain tending tostop the armature 16 in its final position without oscillations. Since this force tending to stop the armature is built up so gradually, substantially no shock occurs which might injure the filament.

In accordance With the provision of the patent statute, I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the apparatus shown is only illustrative, and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent in the United States is:

1. In a positioning device, the combination of a pivoted support and means for sequentially moving said support to a plurality of predetermined positions about its pivot, said means including an electromagnet provided with a pair of field poles, an armature mounted rigidly on said support, means for normally holding said armature in a position intermediate said field poles whereby upon'energization of said electromagnet the torqueupon said armature is equal and opposite, and means for unbalancing this torque and thereby initiating a movement of said armature responsive to energization'of said electromagnet, said unbalancing means being operated at each operating movement of said armature for effecting a movement of said armature to predetermined succeeding positions respectively responsive to successive energizations of said electromagnet.

2. In a positioning device, the combination of a pivoted support and means for sequentially moving said support to a plurality of predetermined positions about its pivot, said means including an electromagnet provided with field poles, an armature mounted rigidly on said support, a second armature mounted on said support and movable relatively to said first armature, means for normally holding said support and said armatures in an intermediate position relatively to said field poles, and means operable upon an energization of said field magnet and a corresponding attraction of said armatures to one predetermined position for simultaneously moving said second armature relatively to said first armature whereby upon deenergization of said field coil and a corresponding return to an intermediate position said armatures will be attracted to a predetermined other succeeding position responsive to a succeeding energization of said electromagnet.

3. In a positioning device, the combination of a shaft and means for sequentially turning said shaft to two predetermined operating positions about its axis including an electromagnet provided with a pair of field poles, an armature rigidly mounted on said shaft, a second armature mounted on said shaft and movable relatively to said first armature between two positions, means for normally holding said first armature in a position intermediate said field poles, and means operable upon an energization of said field magnet and a corresponding attraction of said magnets to one of said two predetermined operating positions for moving said second armature relatively to said first armature whereby upon a succeeding energization of said magnet said armatures will be moved to the second of said predetermined operating positions.

4. In a lamp positioning device the combination of a pivoted shaft, a lamp socket mounted on said shaft in spaced relation to the axis of said shaft, means for turning said shaft to position said socket relatively to a reflector including an electromagnet, a pair of field poles, an armature rigidly attached to said shaft and attached by said field poles upon energization of said magnet in either of two positions, means for normally holding said armature in an intermediate position, a second armature movable relatively to said first armature and operable between two positions to determine the operating position to which said first armature is attracted upon energization of said electromagnet, and means operfor turning said shaft to sequentially position said lamp support in a, plurality of operating positions about said shaft axis, said means including a field magnet connected to be energized simultaneously with the said socket, field poles therefor, an armature mounted on said shaft and rigidly at ached thereto, a second armature mounted on said shaft and movable relatively to said shaft and said first armature, means for no, a ly holding said first armature in an intermediate position between said field poles, and

means attached to said second armature and cooperable with said field poles to move said second armature relatively to said first armature at each energization of said field coil whereby at successive energizations of said field coil said first armature is sequentially moved to a plurality of positions relatively to said field poles and said socket is correspondingly positioned about the axis of said shaft in one of a plurality of operating positions. responsive to successive energizations of said field coil.

6. In a lamp positioning device the combination of a shaft, a lamp socket mounted thereon and arranged to support a lamp in spaced relation to the axis of said shaft, means to hold normally said shaft in one position, an armature rigidly mounted on said shaft, an electromagnet provided with a pair of field poles arranged when energized to exert a torque upon said armature and turn said shaft from said normal position to a predetermined operating position on either side of said normal position, and means for sequentially turning said shaft to said operating positions responsive to succeeding energizations of said magnet including a second armature mounted on said shaft and movable between two positions relatively to said first armature and a spring attached to said second armature engaged by said field poles respectively when said first armature moves to an operating position for moving said second armature to an opposite position relatively to said first armature, whereby upon reenergization of said magnet an opposite torque will be exerted thereon and it will move to its other operating position.

WIN'IERTON J. DAY.

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