Title:
SIGNALING SEARCHLIGHT
United States Patent 3764798


Abstract:
A signaling searchlight having a lightweight internal shutter comprising a liding cylinder which is mounted between a lamp and a reflector. Light of selected wavelengths is filtered from the beam emitted by the lamp to obtain a beam for transmitting coded information. The sliding cylinder is moved to transmit or to block off the light beam from reaching the reflector. Retraction of the cylinder to the off position blocks off the beam from the reflector and is also correlated with the means for reducing the power of the lamp. The sliding cylinder moved to the on position allows the beam to reach the reflector and is also correlated with means for applying full power to the lamp.



Inventors:
Manke, Herbert R. (New London, CT)
Flatley, James P. (Norwich, CT)
Application Number:
05/309409
Publication Date:
10/09/1973
Filing Date:
11/24/1972
Assignee:
NAVY,US
Primary Class:
International Classes:
F21V17/02; (IPC1-7): F21Q1/00
Field of Search:
240/22,23,47,46
View Patent Images:
US Patent References:
1367964Illuminating apparatus1921-02-08Hawthorne



Foreign References:
GB285703A
Primary Examiner:
Greiner, Robert P.
Claims:
We claim

1. A searchlight for transmitting coded information which comprises:

2. The searchlight of claim 1 which further comprises a light filtering means for filtering out selected wavelengths of light before transmission of such information.

3. The searchlight of claim 2 wherein said swing arm means comprises a bell and crank mechanism.

4. The searchlight of claim 1 wherein said rotating means are a pair of handles secured to said housing.

5. The searchlight of claim 1 wherein said switching means is a microswitch coupled to said shaft for controlling power to said lamp from said power source.

Description:
STATEMENT OF GOVERNMENT INTEREST

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

BACKGROUND OF THE INVENTION

The present invention relates to transmission of coded information by using searchlights and more particularly to a signaling searchlight having a lightweight internal shutter which allows transmission or blocking off of the light from the searchlight for transmitting coded signals.

Successful Morse code signaling or the like using a high intensity searchlight requires a shutter mechanism which is used to block off, at will, the light beam emitted by the searchlight. The shutter mechanisms which have been most commonly used for signaling purposes are of the vane type wherein the shutter is mounted outside the source of light used in the searchlight. A shutter of this type comprises a plurality of generally parallel slats which are ganged together and are operable as in the case of a conventional venetian blind. When the slats are in the closed position, the light from the source of light is cut off and is thus prevented from reaching the window of the searchlight. When the slats are in the open position, the light from the source of light passes therethrough and reaches the window of the searchlight. By changing the position of the shutter, one is thus able to transmit coded information. The handle operating the slats is spring loaded and holds the shutter in closed position when the searchlight is not being used for signaling. However, such a shutter is too heavy to manipulate quickly and smoothly and usually weighs about 21 pounds. Furthermore, such a shutter requires a longer searchlight housing for its installation and thus makes a searchlight used for signaling bulky and cumbersome.

SUMMARY OF THE INVENTION

The objects and advantages of the present invention are accomplished by utilizing a signaling searchlight having a sliding cylinder as a shutter for intermittent transmission of light from a lamp, such as a Xenon lamp, of the searchlight. The internal shutter comprises a sliding or retracting cylinder which is mounted between the lamp and a reflector and is thus classified as an internal shutter. Retraction of the cylinder is accomplished through the use of a swing arm type of mechanism. In the closed or retracted position, the cylinder is positioned completely over the lamp, thus preventing the light beam from reaching the reflector and simultaneously reducing the electric power applied to the lamp by using a switching arrangement. In the open position, the cylinder allows the light beam to fall on the reflector and simultaneously increases the electrical power applied to the lamp through the switching arrangement.

It is an object of the invention to provide a shutter mechanism of a simple design for a signaling searchlight for transmitting coded information using a light beam.

Another object of the invention is to provide a searchlight shutter mechanism which is independent of the size of the light beam reflector and associated collecting optics.

Still another object of the invention is to provide an internal shutter mechanism for a signaling searchlight which is easily adaptable to actuation by electrical means.

Another object of the invention is to have an internal shutter for a signaling searchlight wherein the power applied to the light source is reduced when the shutter is in its closed position, thus reducing waste of power and undesirable heat.

Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings wherein:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of the signaling searchlight of the present invention in accordance with a preferred embodiment thereof, with the beam being transmitted in the direction of the arrow;

FIG. 2 is a fragmentary top view of the searchlight and its shutter mechanism in its closed position; and

FIG. 3 is a fragmentary side view of the shutter mechanism in its closed position.

DESCRIPTION OF A PREFERRED EMBODIMENT

Referring now to the drawings wherein like reference characters designate identical or corresponding parts throughout the various views and more particularly to FIG. 1 thereof, the signaling searchlight having a lightweight internal shutter of the present invention is shown as consisting essentially of a generally rectangular housing or box 10 housing a light source 12, an internal shutter 14, and a reflector 16. The box 10 is mounted on a generally vertical post 18 and is capable of motion about a vertical axis and a horizontal axis. Box 10 has levers 20 and 22 which are connected to the internal shutter 14 for changing the position of the shutter inside the box. Lever 20 is used by a left handed operator and lever 22 is used by a right handed operator to move the shutter. Grip 23 is mounted on the box or housing 10 for the operator to place his second hand thereon for providing a better control on the shutter. When the shutter is in its open position, light is transmitted in the direction of arrow 24.

As shown in FIG. 2, light source or lamp 12 and the internal shutter are mounted coaxially. Lamp 12 is preferably a Xenon lamp having two electrodes 26 and 28 which are energized by a conventional power source. The light emitted by lamp 12 may be filtered to obtain a desired beam, such as an infrared beam, by a generally cylindrical filter 30 mounted coaxially with the lamp, and the infrared beam so obtained falls on reflector 16. As shown in FIG. 2, the reflector 16, which is preferably a paraboloid, is positioned so that the reflected rays are parallel to the optical axis 32. The internal shutter 14 comprises a cylinder 34 which is mounted coaxially with the filter 30. As shown in FIGS. 2 and 3, cylinder 34, in its closed position, completely covers the lamp and thus prevents all the rays from reaching the reflector 16 and the window of the searchlight. Cylinder 34 has guiding plates 36 and 38 attached thereto which slide over guiding rods 40 and 42 respectively. Guiding rods 40 and 42 are fixed at ends 44 and 46 by nuts 48 and 50, and have free ends 52 and 54 respectively. Fixed ends 44 and 46 have a hood attached thereto which prevents any nonreflected or direct rays from being transmitted. Guiding plates 36 and 38 are connected to swing arms 58 and 60 respectively. Swing arms 58 and 60 are connected to a rotating shaft 62 which in turn is connected to outside handles 20 and 22. Movement of the outside handles 20 and 22 by a searchlight operator causes the rotating shaft 62 to rotate which in turn causes the cylinder 34 to move parallel to the optical axis 32 relative to the lamp 12. As shown in FIG. 3, rotation of shaft 62 controls the position of a microswitch 64 for controlling the power to be applied to the lamp 12. When the sliding cylinder 34 is in its closed position covering the lamp, the position of the microswitch 64 is such that the power applied to the lamp is at its minimum, thus cutting down any waste or power and preventing any unnecessary production of heat. With the cylinders 34 in its open position, the light from the lamp 12 falls on the reflector 16 and microswitch 64 is in a position wherein the power applied to the lamp is increased.

Briefly stated, manipulation of handle 20 or 22 of the internal shutter by a searchlight operator, rotates the rotating shaft 62 which in turn moves the sliding cylinder 34 relative to the fixed lamp 12, placing the sliding cylinder either in its closed position or in its open position as desired by the searchlight operator. In its closed position, the sliding cylinder 34 cuts off all rays from the reflector 16 and sets the microswitch 64 in a position wherein reduced power is applied to the lamp. The cylinder, in its open position, permits rays to reach the reflector 16 and sets the microswitch 64 in a position wherein full power is applied to the lamp. This enables a searchlight operator to send coded information using signals.

Obviously many modifications and variations of the present invention are possible in the light of above teachings. As an example, it is possible to change swing arm type of mechanism to move the sliding cylinder relative to the lamp. It is therefore understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.