Improvements in and relating to Röntgen-ray Apparatus.
Year: 1899

page_text: Improvements in and relating to Röntgen-ray Apparatus.
I, JAMES MACKENZIE DAVIDSON, M.B., C.M., of 76, Portland Place, in the
County of London, do hereby declare the nature of this invention to be as
follows:-
:-
My invention relates to Röntgen-ray apparatus and has for its object to pro-
vide means that will produce stereoscopic images on a fluorescent screen. The
apparatus is more particularly designed for surgical uses but obviously it may be
employed for other purposes.
It is well known that if a Crookes' tube be displaced to a suitable distance,
say for example of six centimeters, and two skiagrams of an object be taken on
two separate photographic plates, that the two resulting skiagrams properly
mounted and viewed will be seen in stereoscopic relief. My invention is to enable
the shadow of an object to be seen on the fluorescent screen in stereoscopic relief.
In carrying out my invention I employ two induction coils or equivalent
generators each joined up respectively to the battery or other source of electrical
energy, and to the Crookes' or other vacuum tubes employed, and to an inter-
rupter. The two tubes are placed side by side so that the point on their respective
anodes from which the Röntgen-rays originate are in a horizontal line, at a
distance of six centimeters or more from each other. On the same horizontal level
and in a parallel plane I form, in a suitable structure, two sight holes in front of
which two appropriately-mounted shutters are reciprocated or otherwise moved
by an electro-motor or other operating mechanism in such manner that when
one sight hole is open the other is closed. Attached to these shutters, or to the
apparatus which operates theni, are two mercury contact-breakers or other inter-
rupters and the arrangement is such that when the sight hole opposite the one
eye of the operator is open one of the said tubes will be in circuit and momen-
tarily illuminated and, if a fluorescent screen be interposed in the usual way with
an object aginst it, a shadow of the object will result from the illumination of
this one tube. Then the first-mentioned sight hole will be closed and the circuit
of the corresponding tube broken whilst the sight hole opposite the other eye
will be opened and the other tube illuminated. If the machine be made to operate
at such rate that the shutters opposite each eye are opened and closed not less
than ten times per second, the images seen by each eye become continuous and
the brain fuses the image from each eye with the result that a shadow picture in
striking stereoscopic relief produced.
In some cases I may employ the Webnelt electrolytic break, in which case the
mercury contact-breaker acts as an ordinary make-and break contact.
Instead of alternately opening and closing the shutters by a reciprocating
action I may employ a rotating disc provided with suitable perforations; or,

page_text: further, I might employ alternate and synchronous shutters for the eyes and in
front of the two said tubes.
Dated this 28th day of April 1899
A. F. SPOONER,
323, High Holborn, London, Agent for the Applicant.
Миргоѵещению шапu terating vo монgen-ray аррагати.
I, JAMES MACKENZIE DAVIDSON, M.B., C.M., of 76, Portland Place, in the
County of London, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:
My invention relates to Röntgen-ray apparatus and has for its object to provide
means that will produce stereoscopic images on a fluorescent screen.
The appara-
tus is more particularly designed for surgical uses but obviously it may be
employed for other purposes.
It is well known that if a Crookes' tube be displaced to a suitable distance, say
for example of six centimeters, and two skiagrams of an object be taken on two
separate photographic plates, that the two resulting skiagrams properly mounted
and viewed will be seen in stereoscopic relief. My invention is to enable the
shadow of an object to be seen on the fluorescent screen in stereoscopic relief.
In the accompanying drawings, which are mainly diagrammatic,
Figure 1 shows in elevation, and
Figure 2 in plan, an arrangement for effecting my purpose.
Figure 3 is a transverse section on the line A-B Figure 1, and
Figure 4 is a sectional elevation on the line C-D Figure 3.
Figures 5 and 6 are similar views to Figures 3 and 4, and
Figure 7 is a sectional elevation on the line E-F Figure 6, illustrating a modi-
fication hereinafter referred to.
Figure 8 is a similar view to Figure 6, illustrating a further modification, and
Figure 9 is a sectional elevation on the line G-H in Figure 8, showing another
form of interrupter.
Figure 10 is a perspective view of one form of reversing key.
Figure 11 shows diagrammatically the electrical connections thereof, and
Figure 12 is another diagram illustrating an alternative form of reversing key
and its connections.
On
In carrying out my invention I generally employ two induction coils 1 and 2
or equivalent generators each joined up respectively to a battery, one of which
is shown at 3, or other source of electrical energy, and to a Crookes' or other
vacuum tube 4 or 5. The two tubes 4 and 5 are placed side by side so that the
points on their respective anodes from which the Röntgen-rays originate are in
a horizontal line, at a distance of six centimeters or more from each other.
the same horizontal level and in a parallel plane I form, in a suitable framework
structure 6, two sight holes 7 and 8 in front of which two appropriately-mounted
shutters 9 and 10 are reciprocated or otherwise moved by an electro-motor 11 or
other operating mechanism in such manner that when one sight hole is open the
other is closed. Attached to these shutters 9 and 10, or to the apparatus which
operates them, are two mercury contact-breakers or other interrupters 12 and 13
and the arrangement is such that when one sight hole (say the one marked 8) is
open, one of the said tubes (say the one marked 4) will be momentarily illumi-

page_text: nated and, if a fluorescent screen 14 be interposed in the usual way with an object
against it, a shadow of the object will result from the illumination of this one tube.
Then the said sight hole 8 will be closed and the one 7 will be opened and the
tube 5 illuminated. If the machine be made to operate at such rate that the
shutters opposite each eye are opened and closed not less than ten times per
second, the images seen by each eye become continuous and the brain fuses the
image from each eye with the result that a shadow picture in striking stereo-
scopic relief is produced.
In Figures 3 and 4 the shutters 9 and 10 are shown as being carried upon
rods 14 and 15. A shaft 17 is driven by the electro-motor 11 and upon this shaft
are two eccentrics 18 and 19 which respectively come in contact with the upper
and lower cross-bars of two frames 16 and 16* and by means of which the said
rods 14 and 15 are reciprocated. Also attached to the said frames and operated
by the said eccentrics are two rods 20 and 21 which alternately enter and leave
the said mercury cups 12 and 13.
Instead of employing reciprocating shutters I may, as shown in Figures 5 and
6 alternately open and close the sight holes by means of a rotating disc 22. This
disc is provided with two slots 23 and 24, 23 being in register with the sight
hole 7 and 24 with the one 8. The disc may be mounted directly upon the
shaft 17 of the motor and the same shaft will, as before, carry the two eccentrics 18
and 19 and rods 20 and 21 for making and breaking contact.
In Figure 8 is shown an alternative means of effecting the make-and break in
the primaries of the induction coils 1 and 2 employing two interrupters 66 and 67,
each of which consists of a vessel 62 composed of insulating material. The vessels
are provided respectively with a connection 48 and 56 adapted to make contact
with a quantity of mercury 49 and 58. These vessels 62 are respectively pro-
vided with a rotary contact 50 and 57, carried by the shaft 17 at a slight distance
above the level of the mercury, into which the said rotary contacts are alternately
dipped and withdrawn, at every half revolution. The shaft 17 enters the ves-
sels 62 through glands 68 and rotates in a suitable insulating fluid 69 which
enables an effective make-and break " to be accomplished without violently
agitating the mercury.
65
In some cases I may, by employing a suitable reversing key, change over the
electrical connexions so that, at will, either the sight hole 7 is open at the time
that the tube 5 is illuminated and vice versa as indicated by the dotted lines in
Figure 2, or while the sight hole 7 is open the tube 4 may be illuminated
and vice versa. In the first instance (that is to say as indicated by the dotted
lines in Figure 2) the shadow will be seen in true stereoscopic relief and in the
latter case a pseudo-stereoscopic shadow will, in accordance with the laws of binoc-
ular vision, be produced. This reversal of appearance, at will, is of great utility
in determining the exact location of an object.
Figure 10 shows in perspective one form of reversing key adapted for the pur-
pose and the complete electrical connections can be traced from the diagram
Figure 11. Carried on an insulating base 25 are cups 26, 27, 28, 29, 30, 31, 32
and 33 containing mercury. Mounted between uprights 34 and 35 is a pivoted
member 36. This pivoted member 36 carries dependent insulated bifurcated con-
tact-pieces 37, 38, 39 and 40 and attached binding-posts 41, 42, 43 and 44. As
will be seen by Figure 11 there are electrical connections 45 hetween the cups 26
and 32; 27 and 33; 28 and 30, and 29 and 31 respectively. Assuming the pivoted
member 36 to be canted in the direction indicated by the arrow so as to dip the
insulated contact-pieces 37, 38, 39 and 40 into the mercury cups 26, 27, 28 and 29
respectively, a circuit will be closed through the primary of the induction coil 1
by way of the conductor 46, mercury cup 26, insulated contact-piece 37, binding
post 41, conductor 47, binding post 48. mercury 49, rotating contact 50, shaft 17,
conductor 51, binding post 42, insulated contact-piece 38, mercury cup 27, con-
ductor 52, the said primary coil 1 and back to the battery 3 through conductor 53:
while the primary of the other induction coil 2 will receive its current by way of

page_text: the conductor 54, mercury cup 29, insulated contact-piece 40, binding post 44,
conductor 55, binding post 56, mercury 58, rotating contact 57, shaft 17, con-
ductor 51, binding post 43, insulated contact-piece 39, mercury cup 28 con-
ductor 59, the said primary coil 2 and back to the battery 60 through the con-
ductor 61. In this way it will be seen that the action of the induction coil 1 is
controlled by the rotating contact 50 while the other induction coil 2 is controlled
by the contact 57. When it is desired to effect a reversal of the appearance, the
action of the induction coil 1 is controlled by the contact 57 and the action of
the induction coil 2 by the contact 50 by canting the pivoted member 36 so that
the insulated contacts 37, 38, 39 and 40 dip into. the mercury cups 30, 31, 32 and
33 respectively. When the parts are in this position the energizing current of
the primary of the induction coil 1 is conducted from the mercury cup 26 to
the mercury cup 32 through the connection 45, thence through the insulated
contact 39, binding post 43, conductor 51, shaft 17, thence through the rotating
contact 57, the mercury 58, binding post 56, conductor 55, binding post 44,
insulated contact 40, mercury cup 33, and connection 45 to the mercury cup 27.
In the same way it will be seen that the energizing current of the primary of
induction coil 2 may be traced to the rotating contact 50.
The reversing key shown in Figure 12 consists of a drum of insulating
material 70, journalled in uprights 71 and provided at each end with a metallic
ring 72, each having at diametrically opposite points a lateral finger 73 extending
slightly beyond the central zone of the drum. Co-operating with these parts are
four brushes, two of which 74 and 75 are continuously in contact with the
rings 72 respectively while the other two 76 and 77 are caused to complete the
circuit through one or other of the lateral fingers 73, according to the position of
the drum 70 whereby the induction coils 1 and 2 are actuated by the inter-
rupters 66 and 67 respectively or vice versa, as is clearly shown in the drawing.
By means of the arrangement last described both the coils 1 and 2 may be cut
out by turning the drum 70 by its handle 78 into a central position.
In some cases I may employ the Wehnelt electrolytic break, in which case the
mercury contact-makers hereinbefore referred to act as ordinary make-and-break
contacts.
Obviously similar results to those hereinbefore described might be attained by
employing in lieu of the devices illustrated, alternate and synchronous shutters
for the eyes and in front of the said tubes.
Likewise instead of employing an induction coil for each tube the arrangement
might be such that with the aid of a commutator switching device each tube
might successively and at the required momentary intervals be put in circuit
with the one induction coil.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:
1. In a Röntgen-ray apparatus the combination with a fluorescent screen and a
framework structure having two sight holes, of means serving to project upon the
said screen intermittent and rapidly-alternating shadows, and further means
serving to alternately open and close the sight holes of the apparatus so as to
enable the shadow of an object to be seen on the fluorescent screen in stereo-
scopic relief.
2. A Röntgen-ray apparatus, comprising, in combination, a fluorescent screen,
two vacuum tubes, and a battery induction coil and interrupter associated with
each tube, a framework structure with two sight holes, alternately-operating
shutters in front of said sight holes, and means serving to operate the shutters
and interrupters whereby the vacuum tubes are intermittently illuminated and
a stereoscopic image produced on the fluorescent screen.
3. A Röntgen-ray apparatus, comprising in combination, a fluorescent screen,
two vacuum tubes, and a battery induction coil and interrupter associated with

page_text: each tube, a framework structure with two sight holes, alternately-operating
shutters in front of the sight holes, means serving to operate the shutters and
interrupters whereby the vacuum tubes are intermittently illuminated and a
stereoscopic image produced on the fluorescent screen, and further means serv-
ing to change over the electrical connexions so that at will the shadow of an
object may be produced either in true or in pseudo-stereoscopic relief.
4. The Röntgen-ray apparatus constructed substantially as described and as
illustrated in the accompanying drawings.
Dated this 27th day of January 1900.
A. F. SPOONER,
323, High Holborn, London, Agent for the Applicant.