US 2257933 A
Description (OCR text may contain errors)
Oct. 7, 1941. H. D. BELKNAP IDENTIFYING PLATE FOR RADIOGRAPHS Filed April 23, 1940 ,H il \||V]l.,| .3 Ewm 51 4 ym AB M W //VL/E/\/ ma HUEARTD. BEL/(NAP 9 .0 Em m7 .E M
3 4 X E D A mRA/E/ Patented Oct. 7, 1941 UNITE D STAT ES PAT E N T OFF I I I I 2,257,933
I])ENTIFYI'NGL- PLATE'FOR RADIOGRAPHS Hobart D. Belknap, Portland, Oreg.
Application April 23, 1940, Serial No. 331,143
r g 5 Claims. Thisinvention relates generally to radiography andiparticularly to a plate for identifying radiographs.
The first object is to utilize the highly ductile property of sheet lead and also make use of the 1 high resistivity of the lead tothe passage of X- rays for the purpose of producing an identifying plate wherein characters are formed by reducing th resistance of the plate at predetermined portions thereof. The second object is to construct an improved form" of plate of lead or other high resistant material, and having a relatively rigid border incorporated therewith for the purpose of maintaining the lead sheet in a flat, smooth condition and to protect same against injury while arfixing the characters, or whil handling or storing the radiograph records.
The third object is to devise an identifying plate for rad-iographs which will beinexpensive to manufacture and which when the record is made thereon will tend to sharpen the outline of the characters along the edges thereof by utilizing any unevenness existing where any excessive force was applied to the type bar in order to further increase the density of the lead around the characters being formed.
These and other objects are accomplished in the manner set forth in the following specification as illustrated in the accompanying drawing, in which:
Fig. 1 is the front elevation of a form of identifying plate.
Fig. 2 is a section taken along the line 22 in Fig. 1.
Fig. 3 is a fragmentary section taken along the line 3-3 showing the manner in which the border material is compressed to the thickness of the lead plate.
Fig. 4 is a view similar to Fig. 1 showing the condition of the plate prior to the closing during its final assembly.
Fig. 5 is a fragmentary side elevation showing the relation of the plate to the platen and the type bar coming up to a striking position.
Fig. 6 is a fragmentary transfer section through a plate showing at a much enlarged scale the manner in which the type bar engages the plate and is stopped thereby.
Fig. 7 is a fragmentary plan of one corner of a radiograph showing the manner of which the identification is placed.
Similar numerals refer throughout the several views.
Before entering into an explanation of this to similar parts invention it will be understoodthat the use'o f" lead for shielding sensitized photographic film's or plates is commonly used in'the art. In its commonest form lead letters are mounted transparent rectangular pieces. of material of standard width and the various letters are picked; out and assembled in a frame somewhat after the fashion of'a printers composing stick. This frame is placed between the sensitized surface and the X-ray generator, causing the characters to be formed on the radiograph. This method is expensive as well as laborious and consumes an objectionable amount of time for a task at which speed is an important consideration. Moreover; plates of this type are necessarily large; this being an objection, especially on the smaller; sizes of radiographs. y
In some cases permanent titles have been made by:forming stencilsin lead sheets. That is, outting out the metal altogether-f While thispractice has some advantages over the use of the movable letters, it is slow and cumbersome and owing to the fact that the stencil is out through the lead sheet and the X-rays do not project in parallelism with each other, it follows that shado-ws will be formed around theedges of the characters, that is, the edgeswil l become dimmed.
Attempts have been made to adapt the use of a lead sheet to an ordinary type writing machine with or without the use of special type bars. This means is objectionable owing to the fact that the lead sheet being necessarily thin, unattached portions of the letters formed would often be cut away thereby detracting from the legibility of the record.
To overcome this objection, a plan has been devised with a backing of a material other than lead which wasafiixed to the lead sheet for the purpose of supporting all the portions of the letters in a manner to prevent the accidental loss of same due to over striking. This last described form of device while having some advantages over its predecessors is objectionable as to first cost and increased thickness as well as the difiiculty of obtaining a uniform impression. It is to overcome these objections that I have developed the present invention.
Referring in detail to the other drawing there is shown a sheet of lead of a thickness suitable for the purpose around the edges of which is disposed a metallic frame whose sides I 2 and I3, are preferably compressed into the body of the lead sheet III in a manner to provide a substantially flat and smooth surface l4 across the entire area of the device. It will be understood that the combined sheet 10 and frame ll constitute the plate which is used to identify the radiographs.
It will be noted that the side I2 is somewhat wider than the side IS in order that the surface of the side 12 may be used to carry any general information l5 such as the name of the laboratory used in the plate and the manufacturers name or any other information which is applicable to a given group of plates.
The identification characters [5 are formed in the surface [4 by striking same therein with the type bar I! of a typewriting machine (not shown). The type bar I! has formed thereon the sharpened lead displacing element i8 whose edge I9 is spaced from the type bar face 251, a lesser distance than is the thickness of the sheet In in order to make it impossible for the edge E9 to pierce the lead sheet Ill by over-striking.
It will be noted in Fig. 6 that the face 20 of the type bar I! penetrates a short distance into the surface I4 of the lead sheet 10. In other words, the lead sheet I0 acts as a cushion stop for the type bar, not only avoiding any particular efiects from over striking but actually improving the sharpness of definition of the characters l6 by increasing the density of the lead immediately surrounding these characters.
Attempts have been made to accomplish this result by having the type bar strike against a stop other than the sheet upon which the character is to be impressed. If such stop is of a nature to. make same accurate it will be noisy and since a clearance between such stop and the work is a matter of necessity and variations in the gauge of the sheet are practically unavoidable, it follows that these two sources of error render the use of a stop other than the sheet itself impractical.
It will be understood that in the use of my invention that it is desirable to employ a typewriting machine having a fiat or straight platen 2|, having the guides 22 for holding the frame H and its included lead sheet I0 in position for writing thereon. Any of the well known mechanisms have provided lateral and line spacings will be employed without departing from the spirit of this invention.
It will be noted that in the Fig. 7 the radiograph 23 is darkened by the exposure while the area 24 is light, due to the fact that it has been shielded by the lead plate l0 causing the characters ISA to appear positively, that is in black lines upon the light field area 24.
While I have thus illustratedand described my invention, it is not my intention to be limited to the form herein given, but I intend to cover all such forms and modifications, thereof, as fall fairly within the appended claims.
1. .An identification plate of the class described consisting of an extremely thin, soft lead sheet having a rigid supporting frame of aluminum disposed about the periphery thereof adapted to hold said sheet of lead in a taut position.
-2. An identification plate of the class described consisting of an extremely thin lead sheet having a wide rigid supporting frame of aluminum disposed about the periphery thereof, said frame being adapted to hold the sheet in a taut position, said sheet being of substantially the same thickness as is the body of said lead sheet.
3. An identification plate of the class described consisting of an extremely thin lead sheet having a wide rigid surrounding frame adapted to hold said sheet taut and having identifying characters formed in the lead portion thereof by lateral displacement of the metal therein, whereby the density of the metal around the characters is increased and having the over all thickness of metal in said sheet of substantiallythe same thickness throughout.
l. An identification plate of the class described consisting of a flat sheet of thin lead foil having a wide aluminum stiffening band embeddedin the periphery thereof.
5. An identification plate of the class described consisting of a sheet of lead foil approximately one-hundredth of an inch in thickness and having a wide aluminum stiffening frame around its outer edge embedded in the surface thereof in a. manner that the total thickness of the frame will approximate the thickness of the lead sheet.
HOBART D. BELKNAP.