US1729647A - Therapeutic lamp - Google Patents

Description

Oct. 1, 1929. w. H. CLIFFORD THERAPEUTIC LAMP Filed Sept. 6, 1928 /NVENTOR. d/Zm W/%w Patented Oct. 1, 1929 UNITED STATES WILLIAM HUGH CLIFFORD, OF LQNDON, ENGLAND THERAPEUTIC LAMP Application filed September 6, 1928, Serial No. 304,257, and in Great Britain December 19, 1927.

The present invention relates to improvements in therapeutic lamps for light ray treatment and more particularly to the metal casings and filter holders of such lamps. These filter holders are commonly known in the trade as screens.

The ventilation of lamp casings generally and particularly the ventilation of those sheet metal casings now used in connection with therapeutic lamps, have engaged the attention of inventors for some years past and it is a very usual practice to provideventilation holes in front of as well as behind the lamp bulb within a lamp casing.

In an earlier British patent specification in my name No. 233,249 I have described ascreen adapted to hold a light filter comprising two frame members hinged together to form the filter holder and a loose frame adapted to lie within the holder and to be pressed by springs on the inner wall of one of said hinged frame members against the filter when in position in the holder. The light openings in the holder thus formed may be provided with wire gratings to prevent the gelatine or other filter from buckling when subjected to the heat of the lamp. The above described holder is adapted to he slipped into a slide at the mouth of the lamp casing.

The present invention provides instead of a separate holder adapted to be placed in a slide in the mouth of the lamp casing a lamp casing with a cap forming the filter screen adapted to fit over a ventilated flange ring at the mouth of said casing, the filter within the cap being held in the position in use by pressure between the edge of said flange and the top of the cap.

To carry out the invention the cap may be attached to the mouth of the lamp casing by bayonet slots and locking screws. The filter sheet which forms the screen may be held in position by a loose inner screen adapted to lie within the cap against the filter sheets when the latter are in position. This inner screen is in the form of a sheet metal ring fitted with cross wires adapted to prevent the filter sheets from buckling inwards, and is held in position by the edge of the flange at the mouth of the casing when the screen cap is placed in position.

A therapeutic lamp according to the invention is shown by way of example in the accompanying drawings, in which Figure 1 is a side View of the lamp.

Figure 2 is a section through the lamp cap and the mouth of the lamp casing. showing the filter sheets in exaggerated relation within the lamp cap.

Figure 3 is a perspective view of one of the bayonet fastenings of the cap.

Figure 4; is a plan view of the interior of the cap, and

Figure 5 is a plan view of the loose ring which cooperates with the cap to retain the filter in position.

In the drawings a lamp casing a is shown of a. usual form for a high frequency lamp provided with a series of ventilation holes .7) behind the lamp adapted to allow the heated air to escape freely from the lamp casing when the lamp is used in a vertical or semivertical position. As shown in Figures 1 and 2 the mouth of the casing a is provided with a flange ring adapted to receive the ca (Z which forms the screen or holder for the filter sheets. That portion of the flange behind the cap is provided with a series of ventilation holes 0 of larger diameter than the ventilation holes I) in the body of the casing. These ventilation holes 0 are designed to allow of a rapid and free escape of the heated air from the casing between the lamp and the filter 72, in the cap (Z. Such a free ventilation is very necessary when filters in the form of superposed gelatine sheets are used for the reason that they run together and soon become useless when subjected to high temperatures. Again, if glass filter sheets are employed they may crack from the heat of the lamp unless there is a free escape from the lamp casing for the heated air.

The casing cap (Z which forms the screen or holder for the filter is adapted to be placed on the flange ring at the mouth of the casing a as shown in Figures 1 and 2 and is locked in position thereon conveniently by nuts 9 on set screws on the flange which screws engage in bayonet slots 6 in the edge of the cap (Z when the latter is placed over the flange.

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The light opening in the cap is conveniently provided with cross wires Z which prevent the filter sheets from buckling or bulging through the opening. Similar cross wires m are provided in the light opening of the screen ring is which is adapted to lie within the cap as shown in Figure 2 against the filter sheets when these are in position. This loose inner screen ring is conveniently in the form of a sheet metal ring as shown in Figure 5. This ring is held in position by contact with the edge of the mouth of the casing when the cap is locked thereon.

In Figure 1 I show a lamp casing designed to be mounted on a stand and set at the desired angle by means of the handle 1".

It should be understood that any alternative method of mounting the lamp casing in the horizontal or vertical plane is within the scope of-the invention. For instance, the lamp casing may be pivoted in a U-frame supported from the ceiling so as to be ad justed as to height and the lamp adapted to hang vertically downwards thereon or horizontally as desired.

What I claim is i 1 1. A therapeutic lamp casing comprising a ventilated flange ring at the mouth of the casing, a cap adapted to fit over said flange ring, filter sheets adapted to liewithin said cap, a loose inner ring adapted to lie in said cap between said filter sheets and the edge of said flange ring when the cap is inposition on said ring and means on said ring for preventing the filter sheets from buckling inwards. 2. A therapeutic lamp casing comprising a ventilated flange ring at the mouth of the casing, a cap adapted to fit over said flange ring, filter sheets adapted to lie within said cap and a loose metal ring fitted with cross wires to prevent the filter sheets from buckling inwards adapted to lie in said cap between said sheets and the edge of said ring when the cap is in position on said ring.

3; A therapeutic lamp casing comprising a ventilated flange ring at the mouth of the casing, a cap adapted to fit over said flange ring filter sheets adapted to lie within said cap, a loose metal ringfitted with cross wires to prevent the filter sheets from buckling inwards adapted to lie in said cap between said sheets and the edge of said ring when the cap is in position on said ring and aseries of locking screws on the flange ring coacting with corresponding bayonet slots on the edge of the cap forholding said cap on the mouth of the casing.

In testimony whereof I have signed my name to this specification.

' IVILLIAM HUGH CLIFFORD.

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