Blood serum applicator for use in cataphoretic apparatus

The serum application for use in a cataphoretic apparatus comprises a penpoint which is mounted on the lower end of a plate-shaped penpoint support member, the upper end of which is formed with a hook to permit the support member to be suspended from a support arm to maintain the serum applying surface of the penpoint in parallel relationship with the surface of a serum bearing member. The upper end face of a support arm which is engaged by the hook is formed to lie in a plane parallel to the surface of the serum bearing member. The penpoint support member is vertically slidable relative to the vertical major surface of the support arm by providing a guide pin and guide slot arrangement.

BACKGROUND OF THE INVENTION 
The invention relates to a blood serum applicator for use in cataphoretic 
apparatus, and more particularly, to such applicator which may be used to 
apply a sample of blood serum to a serum bearing member. 
As is well recognized, an automatic cataphoretic apparatus is arranged to 
perform the supply of a serum bearing member, the application of a serum 
thereto, a cataphoretic process, the steps of dyeing, decolorizing and 
drying, photometry and recording in a sequential and automatic manner (see 
pending U.S. patent application Ser. No. 829,957 and German patent 
application No. P 27 40 073.3). Specifically, a roller which wets a serum 
bearing member with a buffer solution feeds it into a serum application 
station where a blood serum to be examined is applied to the bearing 
member, which is then supplied into a cataphoresis vessel. A cataphoretic 
process takes place within the vessel, and after the completion of the 
cataphoretic process, the bearing member is transferred into a dyeing 
vessel where the steps of dyeing, decolorizing and drying take place. The 
dried bearing member is subject to photometry with a densitometer. The 
data obtained by the photometry is recorded by means of a recorder. 
A blood serum bearing member comprises a sheet of cellulose acetate to 
which blood serum is applied with a penpoint application in a rectilinear 
form of a given narrow width. The serum is then electrically energized to 
obtain a fractionated pattern of the serum. 
A conventional serum application is illustrated in FIGS. 1 and 2. Referring 
to these Figures, the serum applicator comprises a plurality of serum 
application members 3 which are carried by a support arm 4 in 
juxtaposition. The member 3 includes a plate-shaped penpoint 1 having an 
applying surface 1a which is attached to a support shank 2. The support 
shank 2 fixedly carries a pin 5 which is fitted in a slot 4a formed in the 
support arm 4, thereby allowing a limited vertical movement of the 
penpoint as permitted by the vertical extent of the slot. In use, the 
support arm 4 is lowered to immerse the penpoint 1 of the individual 
application members 3 into a supply of blood serum. After the serum is 
applied to the surface 1a of the penpoints, the support arm 4 is raised 
and moved to a location over a blood serum bearing member 6 where it is 
lowered to move the application members 3 down so that the surfaces 1a may 
be brought into contact with the bearing member 6, thus applying the serum 
to the latter. 
However, the described construction of the serum application results in a 
disadvantage that the serum is deposited on the bearing member in a 
deformed form, as illustrated in FIGS. 3(C) and (D). Specifically, the 
support arm 4 is channel-shaped so as to have a pair of limbs 4d, 4e which 
are formed with openings 4b, 4c extending therethrough for allowing the 
shank 2 to pass therethrough. It is difficult to achieve a high accuracy 
in the size and location of openings 4b, 4c. If the vertically spaced 
openings are misaligned or if there is any clearance between the edge of 
the openings and the shank 2, the application member 3 will assume a 
slanted or inclined position. If such an application member is directly 
used in the application of the blood serum to the bearing member, the 
surface 1a of the penpoint 1 will be inclined when abutting against the 
bearing member 6, as illustrated in FIGS. 3(A) and (B). As a consequence, 
the deposition of serum 20 will be offset to one side, as illustrated in 
FIGS. 3(C) and (D). Another difficulty is that of achieving a high 
accuracy in the manufacturing of the pin 5 and its engagement with the 
slot 4a. If the pin 5 extends in a wrong direction or if there is a 
clearance between the pin and the slot 4a, the applying surfaces 1a of the 
individual pin point 1 will not be aligned with each other on the bearing 
member 6 but will be staggered thereon, with the result that the applied 
samples of serum will be similarly staggered when they are subject to a 
cataphoretic process, which is undesirable. 
SUMMARY OF THE INVENTION 
It is an object of the invention to provide a blood serum applicator for 
use in cataphoretic apparatus which eliminates the above disadvantages of 
the conventional serum applicator, by providing support members which 
support serum applying penpoints and which are mounted on a support arm in 
suspended form by their own gravity so that when the support arm is 
lowered, all of the applying surfaces of the penpoints will be aligned 
with each other on a serum bearing member when they are disposed in 
abutment against the latter. 
In accordance with the invention, a support arm in the form of a 
horizontally elongate plate-shaped member has an upper end face which is 
parallel to the surface of a blood serum bearing member. A penpoint 
support member has a hook which is suspended from the upper end face of 
the support arm so that the applying surface of a penpoint is maintained 
parallel to the surface of the bearing member. When the support arm is 
lowered, the applying surfaces are entirely and uniformly in abutment 
against the surface of the bearing member. In this manner, it is assured 
that the blood serum be applied to the bearing member precisely in a 
recilinear form of a given, narrow width. This is also assisted by forming 
both the support arm and the support members from plate-shaped members 
each having a vertical major surface, which are maintained in contact when 
moving the penpoint support members relative to the support arm in the 
vertical direction. This prevents an angular movement of the support 
members. The degree of parallelism between the applying surface of the 
penpoint and the surface of the serum bearing member depends on the 
accuracy with which the upper end face of the support arm and the hook 
surface of the support member are machined. The alignment of the applying 
surfaces of individual penpoint on the bearing member depends on the 
accuracy of machining of the mating vertical surfaces of the support arm 
and support members. However, it will be appreciated that these machining 
accuracies can be significantly improved inasmuch as the involved 
machining operation represents a planing. 
The penpoint support member is vertically movable with respect to the 
support arm by a pin and slot arrangement. Specifically, the support 
member is formed with a vertically elongate guide slot having a lateral 
width which is slightly greater than the diameter of a guide pin that is 
integral with a locking screw which is in turn fixedly mounted on the 
mating vertical surface of the support arm. Consequently, if the applying 
surface of the penpoint is inclined when it is disposed in abutment 
against the bearing member, it will angularly move under gravity as the 
support arm is lowered, thus bringing the entire applying surface of the 
penpoint into abutment against the surface of the bearing member.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIGS. 4 and 5, there is shown a penpoint 11 whicn is in the 
form of a thin, elongate plate member as in the conventional arrangement. 
The lower end face of the penpoint defines a serum applying surface 11a 
which is finished to a plane surface for abutment against the surface of a 
serum bearing member 6. The top of the penpoint 11 is secured to the lower 
end of a penpoint support member 12 by means of a positioning pin 18 and a 
locking screw 19. The support member 12 is in the form of a relatively 
elongate strip. The combination of the support member 12 and the penpoint 
11 together constitute a serum application member 13. 
The upper end of the support member 12 is formed with a hook 12a which 
permits the support member 12 to be suspended from a support arm 14 so as 
to align the applying surface 11a parallel to the surface of the bearing 
member 6. The hook 12a is formed as a lateral extension which is formed at 
right angles to the upper end of the support member 12, and has a lower 
surface 12a' which is adapted to be abutted against the upper end face 14a 
of the support arm 14. The support member 12 is centrally formed with a 
vertically elongate guide slot 12b which cooperates with locking screws 
15, 16 mounted on the support arm 14 for allowing a vertical movement 
thereof. 
The support arm 14 is formed by a plate member which is elongate in the 
horizontal direction, and is disposed to present vertical major surfaces. 
The upper end face as well as the both major surfaces of the support arm 
14 are machined to be perpendicular and parallel to the surface of the 
bearing member 6, respectively. It is to be noted that the support arm 14 
is disposed to be movable relative to the bearing member 6. 
The hook 12a is engaged with the upper end face 14a of the support arm 14, 
by engaging the surfaces 12a', 14a. The rear major surface 12c of the 
support member 12 is disposed in abutment against the front major surface 
14b of the support arm 14. Then the support member 12 is suspended from 
the support arm 14 by gravity. Under this condition, a pair of vertically 
spaced locking screws 15, 16 are inserted into the guide slot 12b, and 
then threadably engaged with the support arm 14. The screws 15, 16 have 
disc-shaped heads 15a, 16a which bear against the edges of the guide slot 
12b, thus preventing the support member 12 from being disengaged from the 
support arm 14. In this manner, the support member 12 is capable of 
sliding vertically relative to the front wall surface of the support arm 
14. 
Part of the locking screws 15, 16 define guide pins 15b, 16b, respectively. 
By way of example, the clearance between pins 15b, 16b and the edge of the 
guide slot 12b may be approximately 0.3 mm. Thus, the slot 12b has a 
lateral width which is slightly greater than the diameter of the guide 
pins 15b, 16b. The provision of such clearance permits an angular movement 
of the penpoint member 12 by gravity as the support member 14 is lowered 
even if the applying surface 11a of the penpoint assumes an inclined 
position when it is in abutment against the surface of the bearing member 
6, thus assuring that the entire applying surface 11a of the penpoint 
bears against the surface of the bearing member 6. 
The support member 12 is vertically movable between a first position in 
which the lower surface 12a' of the hook 12a abuts against the upper end 
face 14a of the support arm 14 and a second position in which the bottom 
12b' of the guide slot 12b bears against the guide pin 16b. When it is 
suspended from the support arm 14,the applying surface 11a of the penpoint 
11 is maintained parallel to the surface of the bearing member 6. 
In operation, the support arm 14 carrying a plurality of serum application 
members 13 is initially lowered to immerse the penpoints 11 in a supply of 
blood serum, thus causing a deposition of the serum on the individual 
applying surfaces 11a. Subsequently, the support arm 14 is raised and 
moved to bring the application members 13 over the blood serum bearing 
member. At this time, the application members 13 are suspended from the 
support arm 14 by their own gravity so that the applying surfaces 11a are 
parallel to the surface of the bearing member 6. The support arm 14 is 
then lowered to cause the abutment of the applying surfaces 11a of the 
individual penpoints 11 against the bearing member 6. At this time, the 
individual applying surfaces 11a lie flat against the bearing member 6, so 
that the serum which is deposited on the applying surfaces 11a migrates 
onto the bearing member 6 by capilary action, in a rectilinear form of a 
given, narrow width. It is expected that the applying surfaces 11a of the 
plurality of the penpoint 11 which are carried by the support arm 14 may 
be located at varying distances from the surface of the bearing member 6. 
In this instance, the application member 13 which has its applying surface 
11a initially engaged with the bearing member 6 will move upwardly as the 
support arm 14 continues to move down, and then other application members 
13 will have their applying surfaces 11a disposed in abutment against the 
bearing member 6. When the application of the serum is completed in this 
manner, the support arm 14 may be raised, whereupon the applying surfaces 
11a of all the application members 13 will move away from the surface of 
the bearing member 6 and will be suspended from the support arm 14 by 
gravity while their applying surfaces 11a are maintained parallel to the 
surface of the bearing member 6. 
From the foregoing description, it will be appreciated that the invention 
enables an accurate application of a blood serum in an automatic manner. 
The present invention may be embodied in other specific forms without 
departing from the spirit or essential attributes thereof and, 
accordingly, reference should be made to the appended claims, rather than 
to the foregoing specification as indicating the scope of the invention.