U.S. patent number 3,654,472 [Application Number 04/756,998] was granted by the patent office on 1972-04-04 for apparatus for selectively examining radioactive samples.
This patent grant is currently assigned to U.S. Philips Corporation. Invention is credited to Jan Sjouke Hof, Gerardus Otten.
United States Patent |
3,654,472 |
Hof , et al. |
April 4, 1972 |
APPARATUS FOR SELECTIVELY EXAMINING RADIOACTIVE SAMPLES
Abstract
An apparatus having a series of movable trays for holding a
plurality of radioactive samples, and for transporting each tray
and each sample carried thereon to a shielded detection unit for
examination.
Inventors: |
Hof; Jan Sjouke (Waalre,
NL), Otten; Gerardus (Emmasingel, Eindhoven,
NL) |
Assignee: |
U.S. Philips Corporation (New
York, NY)
|
Family
ID: |
19801104 |
Appl.
No.: |
04/756,998 |
Filed: |
September 3, 1968 |
Foreign Application Priority Data
Current U.S.
Class: |
250/494.1;
250/328; 976/DIG.373 |
Current CPC
Class: |
G01T
7/08 (20130101); G21F 7/067 (20130101) |
Current International
Class: |
G21F
7/06 (20060101); G21F 7/00 (20060101); G01T
7/08 (20060101); G01T 7/00 (20060101); G01t
007/02 (); G01t 007/08 () |
Field of
Search: |
;250/71.5,16SC
;214/11,16.4 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Borchelt; Archie R.
Claims
We claim:
1. Apparatus for retaining a plurality of sample containers of
radioactive material and transporting one at a time to a detector
for examination, comprising:
a. a frame,
b. a plurality of carriers movably disposed in spaced relationship
on the frame,
c. a plurality of holders, each (i) having a plurality of apertures
along a longitudinal axis for retaining sample containers, and (ii)
secured to and axially movable relative to one carrier,
d. a transfer assembly for maintaining the carriers and holders
spaced and parallel with respect to other carriers and holders, and
for transporting the carriers and holders along a continuous
generally elongated path having closely adjacent sides, with the
carriers and holders on said sides of the path being
correspondingly adjacent, the path also defining a discharge area
to which each holder is transported,
e. a shielded detector including an aperture for receiving one
sample container at a time, and
f. the transfer assembly further comprising means cooperating with
each holder at the discharge area, for selectively moving each
holder axially with respect to its carrier and a selected container
to a discharge point for transport from the holder to said detector
for examination thereof, and returning the container to its
holder.
2. Apparatus according to claim 1 wherein said transfer assembly
moves each holder axially in steps for selectively locating each
aperture of the holder closely adjacent the discharge area, before
each container is transported from each holder to the detector.
3. Apparatus according to claim 1 wherein said transfer assembly
further comprising a tray secured in an upright position to each
carrier, with each holder supported by the bottom of a tray and
each holder aperture being bottomless and oriented vertically,
whereby axial movement of a holder relative to the corresponding
tray permits containers to be moved at the discharge area
vertically downward to the detector.
4. Apparatus according to claim 3 wherein said transfer assembly
further comprises flexible guide means disposed along said path and
motor means driving the assembly for transporting the carriers and
holders.
5. Apparatus according to claim 1 wherein said frame further
includes a closable duct between the discharge area and the
detector, and said transfer assembly opens the duct before
transporting each container via the duct to the detector, and
subsequently closes the duct.
6. Apparatus according to claim 2 wherein the transfer assembly
further comprises a pair of chain links spaced apart and supporting
said carriers therebetween.
Description
The invention relates to a composition changer for examining
radioactive compositions which are present in containers and may be
mixed with a scintillator liquid. The changer is provided with a
plurality of parallel arranged holders which are each designed to
hold a group of containers containing the compositions to be
examined, means to remove a container from the holder, to bring
said container in a shielded detector chamber, to examine it, and
to remove it again from said chamber.
In a known composition changer a group of containers is accomodated
in apertures along a circular periphery of a round disc. This disc
forms a magazine for the containers which may be designed as small
bottles. In this changer a plurality of said discs is fixedly
arranged above one another and every time one disc is completely
moved out of the stack and conveyed up to exactly above a detector
chamber; by rotating the disc about its center a different
container is led every time above the chamber and introduced
therein. After examination the container is placed again in the
disc which is conveyed back to the stack.
Although the known device is suitable for a very large number of
containers, it has the drawback of being comparatively voluminous;
because the containers are only arranged along a circular
periphery. A disc having a large diameter is already required for
proportionally few containers. Furthermore a complicated mechanism
is required for the intricate transport path leading the disc from
the stack to the measuring arrangement.
An object of the invention is to provide a changer in which the
transport path for the containers is considerably simplified and
shortened and which can accommodate a great many containers in a
proportionally small volume. To this end the changer according to
the invention is characterized in that the holders are oblong and
are each designed to accommodate the containers in one or more
parallel straight rows, the holders being movable in parallel with
one another, in a path tranversely to their longitudinal dimension
and closed in itself.
In the device according to the invention all containers are thus
moved in parallel rows along a path closed in itself. When a
desired row has arrived in a pre-determined position in the
afore-mentioned path, the desired container is removed from the
holder by means of suitable members and conveyed to the measuring
position.
Starting from an arrangement in which each holder may be provided
with possibly a double row of containers, one embodiment of a
composition changer has means for moving a holder preferably
stepwise in its longitudinal direction when said holder has assumed
a pre-determined position in the path. This provides the
interesting possibility to accommodate the holders movably in
gutter-like trays which are open at at least one end, said holders
having a plurality of bottomless apertures for receiving the
containers and extending in a vertical direction up to the bottoms
of the trays. The containers, which are, for example, formed as
sample bottles, then fit in the bottomless apertures of the holder
which rests on the bottom of the trough-like tray in unextended
position; not until the holder is slid out of the tray can the
containers be conveyed in downward direction to a measuring
chamber.
For transporting holders along a path which is closed in itself,
use can be made of two chains between which the parallel movable
holders are suspended in such manner that the mutual position of
the containers is maintained during the transport of the holders
along the path. The ends of each trough-like tray can then be fixed
permanently to brackets which are secured to the links of the
chains. In this connection it is otherwise noted that it is known
per se from U.S. Pat. specification No. 3,302,025 to transport a
large number of containers by means of a flexible belt along a
measuring chamber housing a detector, pick-up members being
utilized for removing the containers containing the compositions to
be tested from the belt path and to be conveyed to the measuring
chamber (and vice versa).
In order that the invention may be readily carried into effect it
will now be described in detail, by way of example, with reference
to the accompanying diagrammatic drawings in which:
FIG. 1 is a perspective elevational view of the changer according
to the invention,
FIG. 2 relates to transporting holders containing sample bottles to
be tested, along a path by means of a transport chain,
FIG. 3 is part of a vertical cross-section taken on the line
III--III of FIG. 1, and
FIG. 4 is a perspective view of a transport tray having an
extensible holder for samples to be tested.
The composition changer of FIG. 1 has two transport chains 1 and 3
which are synchronously moved by the same shaft 4 and between which
a plurality of transport trays for sample bottles are suspended in
brackets in the manner as for an endless conveyer. FIG. 2 shows the
chain 3 in part and brackets 5, 7, which have a common pivot at 9
secured to the links of these chains. The brackets 5, 7 are shown
as two lines in FIG. 1. Trough-like trays 19 for holding sample
bottles to be tested are suspended between corresponding sets of
brackets of the two chains. To this end use is made of carrier
plates 11 secured to the brackets 5, 7 which carrier plates have
bent edges 13 between which the trays 19 with their flanged edges
15 and 17 can slide.
Due to the endless arrangement, all holders remain comparatively
horizontal. Each series of parallel arranged trays 19, which are
open at one end, is furthermore designed to comprise a holder 21 of
a synthetic material which can be slid out of the tray 19 in the
longitudinal direction as is shown in FIG. 4. The holder 21 is
provided with bottomless apertures 23 in which containers holding
the compositions to be examined are held in place. In this example
the containers are designed as small bottles 25 which are supported
by the bottom of the tray 19 as long as the holder still completely
remains in the tray.
In the lowest position of the chain path the holders 21 are
successively slid out of the trays 19 in stepwise manner. To this
end reference is also made to FIG. 3. The holder 21 is slid out of
the tray 19 in the longitudinal direction with the aid of a lug 29
which is moved stepwise in the direction indicated by arrow 27 and
co-acts with a hook-like part 31 of the holder 21. In unextended
position the lug 29 is located at the extreme right. The hook-like
part 31 is arranged behind the lug 29 in said extreme right
position by moving the tray 19 in the direction transversely to the
plane of the drawing whereby the part 31 slides over the lug 29. An
index mechanism of conventional construction may serve to move on
the lug 29.
A detector chamber formed by lead walls 37 and accommodating
detection means 39, 41 is located underneath the chain conveyer. A
plunger 43 can be displaced in the direction of height in an
aperture 48 of this chamber; it is driven by a shaft 45 which
causes the pin 47 inserted in plunger 43 to move up and down
through a suitable gear. In its highest position the plunger 43 can
receive a bottle 51 from the holder 21, and hold it between the
detectors 39 and 41 in its lowest position at which the measurement
for radioactivity takes place in conventional manner. The bushing
50 then provides for additional shielding of the light when the
plunger 43 is in its upper position. As the plunger moves down the
bushing is also taken along downwards by shoulder 52.
Furthermore there is provided a shield 55 rotatable by shaft 53 and
having apertures the shield passes a bottle 51 in one position and
covers the space above the lowered bottle 51 in light-tight manner
at one position farther. After measurement shield 55 is further
rotated until another aperture is released in the path of the
plunger, and the bottle 51 can be lifted again into the holder 21.
While the upper side 59 of the plunger 43 is in the broken-line
position and forms a temporary base for the bottle 51, the holder
21 is displaced over a desired distance and another bottle can be
lowered. When an entire row of bottles of a holder has been
handled, the lug 29 is again moved to the extreme right and the
holder 21 is thus returned to its original position. Subsequently
the chains 1, 3 are moved slightly further so that the second row
of bottles of the same holder 21 can be slid out.
The composition changer furthermore comprises an electronic control
section with which a desired program of operations, such as
transporting, measuring, recording, can be carried out. This
section can be seen in the right part of FIG. 1 and comprises a
plurality of control and measuring units placed upon one another.
Since these units do not form an essential part of the present
invention their description has been omitted.
* * * * *