Kny-Scheerer (Kayess) Tube (1918-1925)

Kny-Scheerer (Kayess) Tube (1918-1925)

This tube was manufactured by the Kny-Scheerer Company of New York City. Before WW I, they used a crowned snake coiled around a scepter as their trademark. After WW I they switched their trademark to "Kayess," as in K and S for Kny-Scheerer. The only markings on the tube are the words "Kayess Products" stamped onto the copper jacket of the anode. As is common for late model cold cathode tubes, there is no separate anode and anticathode.

This tube once belonged to Carl Braestrup at New York’s Francis Delafield Hospital. Whether or not he actually used it is unknown. What makes the tube unique is the projection on the glass bulb at the point where the x-ray beam would exit the tube. Although it is hard to tell, the glass does not seem to be any thinner at the projection than anywhere else. One possibility is that the projection was used to help standardize the distance between the tube and the patient. In other words, the projection would have been placed close to, or in contact with, the patients body. It is also possible, and perhaps more likely, that it was used to help position some type of collimator (e.g., a lead glass extension), or to help orient the tube inside a shielded enclosure so that the beam would be directed towards the opening.

The anode (entering the bulb from the left) has a glass jacket extending most of the way along its length. This is to prevent stray electrons from striking the side of the anode and producing x-rays. If this occurred, the x-ray images would be somewhat bluury because the x-rays would be originating from too large an area.

Donated by Cecilia and Maureen Mooney

References

ERN Grigg. Trail of the Invisible Light. Charles C Thomas 1965.

GWC Kaye. X-Rays. Longmans, Gree and Co. London. 1929.

X-ray Tubes Museum Directory