Gripping strip for prefilled disposable syringes

A gripping strip for prefilled disposable syringes having a syringe cylinder. The gripping strip has a gripping strip element formed as a separate synthetic plastic part fixedly mountable on the syringe cylinder, a plate-shaped abutment provided on the gripping strip element and having a hollow cylindrical receptacle with an outer diameter which is adapted to be smaller than an inner diameter of the syringe cylinder, arresting elements provided in a region of an outer surface of the gripping strip element for mounting with the syringe cylinder in a complimentary inner undercut of the syringe cylinder, a safety ring insertable in an interior of the receptacle for maintaining a working connection, the safety ring being connected with the interior of the receptacle of one piece through locations of desired breakage in an unsecured position, so that during placing the syringe cylinder over the receptacle it is displaceable into a securing position. The receptacle has an outer surface which is formed of peripheral portions with gaps therebetween, the arresting elements being arranged in the gaps for a form-locking operative connection with the inner undercut of the syringe cylinder.

BACKGROUND OF THE INVENTION 
The present invention relates to a gripping strip for disposable syringes 
having a syringe cylinder with an end on which the gripping strip is 
fixedly mounted as a separate synthetic plastic part. 
In this construction the gripping strip has a plate-shaped abutment with a 
hollow cylindrical receptacle whose outer diameter is smaller than the 
inner diameter of the syringe cylinder, and in the region of the outer 
surface arresting elements are formed for a form-locking operative 
connection for mounting on the syringe cylinder. The syringe cylinder has 
an inner undercut which is complementary to the arresting elements. In the 
interior of the receptacle, a safety ring is inserted for maintaining the 
operative connection. Syringes for medical and diagnostic purposes have a 
gripping strip on the syringe cylinder which is formed as a counter 
support during pressing of the piston into the syringe cylinder for 
application process, whether its manual or by means of a injection pump. 
This gripping strip is also identified as a finger support and a cylinder 
gripping plate. The connection of the gripping strip with the syringe 
cylinder must withstand pulling out forces, up to 100 N. 
There are two basic concepts for arranging the gripping strip of the 
syringe cylinder. In accordance with the first concept, the gripping strip 
is formed of one piece with the syringe cylinder during its manufacture. 
Because of the geometry of the plate shaped abutment which deviates from 
the circular form, the gripping strip during filling interferes with the 
syringe, and it must have a relatively great distance between the magazine 
syringe bodies projecting during filling. In the case of glass syringes, a 
certain breakage damage and the danger of sliding of the finger during the 
application process exists, which was found by patients to be very 
unpleasant. 
In accordance with a second concept from the which the present invention is 
derived, the gripping strip is formed as a separate synthetic plastic part 
and subsequently, or in other words after the filling process, is mounted 
on the syringe cylinder which can be composed of glass or synthetic 
plastic. With this concept the disadvantages of the first concept with the 
one-piece formed gripping strip can be eliminated. 
Since the gripping strip must withstand high pulling out forces, the 
strength or stability of the connection of the synthetic plastic gripping 
strip with the syringe cylinder is especially important. 
It is known to mount the syringe cylinder in the interior of the hollow 
cylindrical receptacle of the gripping strip. This type of mounting has a 
substantial disadvantage that the wall of the hollow cylindrical 
receptacle projects opposite to the diameter of the syringe cylinder with 
a sharp edge transition to the syringe cylinder. The required axial 
expansion of the receptacle takes over the outer surface of the syringe 
cylinder which is required for example, for the label. This axial 
extension interferes during the reception of the syringe in the injection 
pump, and with certain pump types prevents such a reception. On the other 
hand, in the known gripping strips, a relatively great synthetic plastic 
mass is needed for manufacture. This is on the one hand unfavorable for 
the disposal and on the other hand increases manufacturing costs, the 
features which are extremely important for disposable articles. In 
addition, the arrangement of the mounting of the gripping strip is 
relatively expensive. 
In the above mentioned patent document DE 39 24 830 A1, the finger 
application on the syringe cylinder must be relatively simply arrestable 
with the use of a louver baffle cap, but such a connection withstands only 
low pulling out forces. As a rule, the synthetic plastic griping strip 
shrinks under the action of preliminary heating. This step requires 
substantial expenses during the manufacture, or in other words, an 
expensive mounting, to provide a very accurate temperature control. In 
addition, when the gripping strip is too cold, it can not be mounted, but 
when the temperature is too high, it can melt. The heating negatively 
influences the filling agent and also interferes with the filing in the 
cleaning chamber in which it is desired to obtain a flow from above 
downwardly, which is disturbed by the upwardly oriented heat flow. 
The patent document WO 92 08507, FIG. 1 (equivalent to U.S. Pat. No. 
5,364,369, FIG. 17) discloses a gripping strip for prefilled disposable 
syringes with the syringe cylinder, having an end with a gripping strip 
fixedly mounted on it as a separate synthetic plastic part. It has a 
plate-shaped abutment with a hollow cylindrical receptacle having an outer 
diameter which is smaller than the inner diameter of the syringe cylinder. 
An arresting element formed as a ring groove is provided in a socket-like 
manner on the outer surface of the hollow cylindrical receptacle, or a 
form-locking operative connection with the syringe cylinder which has a 
complementary inner edge bead. 
In this known gripping strip, the receptacle is mounted in the interior of 
the syringe cylinder. Thereby the gripping strip does not occupy any 
surface of the outer casing of the syringe cylinder, there is no sharp 
edge transition between the gripping strip and the casing of the syringe 
cylinder which can cause an injury danger, and due to the geometry the 
syringe is insertable in injection pumps in a simple manner without any 
problems. 
The principal disadvantage of this construction is however that the 
gripping strip can not withstand any high pulling out forces, since the 
form-locking arresting connection can be readily releasably released. The 
above mentioned WO 92 08507 document in FIG. 5 shows an alternative 
embodiment with an inner undercut on the syringe cylinder and a 
complimentary edge bead on the hollow cylindrical receptacle, with an 
additional outer arresting connection composed of a edge bead on the 
syringe cylinder and a claw-shaped formation on the plate-shaped abutment 
of the gripping strip. The pulling forces which it withstands in this 
embodiment are also low, since the form-locking connection can be easily 
broken. In addition, due to the deviation from the cylindrical shape on 
the base of the syringe cylinder, the insertion into the injection pumps 
causes certain problems. 
The same is true for the above mentioned U.S. Pat. No. 5,364,369 which in 
FIG. 13 shows the gripping strip with the hollow cylindrical receptacle of 
separate peripheral portions and formed projections for an outer 
form-locking connection with an outer border edge formed on the edge of 
the syringe cylinder. 
The German document DE 44 34 614 A1 discloses in FIG. 1C the above 
identified gripping strip which can withstand high pulling out forces. The 
reason is that the form-lock of the operative connection is maintained by 
the safety ring and is insertable in the injection pump without any 
problems, since a small cylinder surface is available up to the abutment 
of the gripping grip. 
The known gripping strip requires relatively high manufacturing and 
mounting expenses. It must be produced with two separate parts, namely the 
plate-shaped abutment with the receptacle and the safety ring, and must 
have these parts on the device to be supplied to the manufacturing 
process. In addition, the material consumption is very high due to the 
massive design of the gripping strip part, that has the above mentioned 
negative consequences with respect to the disposability and manufacturing 
cost, which is exceptionally important in the manufacture of mass 
articles. 
SUMMARY OF THE INVENTION 
Accordingly, it is an object of the present invention to provide a gripping 
strip of the above mentioned general type, which avoids the disadvantages 
of the prior art. 
More particularly, it is an object of present invention to provide a 
gripping strip which has lower manufacturing and mounting expenses as well 
as material consumption. 
In keeping with these objects and with others which will become apparent 
hereinafter, one feature of present invention resides, briefly stated, in 
a gripping strip in which the safety ring is connected of one piece with 
the receptacle through points of desired breakage in an unsecured 
position, and during placing of the ejection cylinder over the receptacle 
is displaced to the secured position, and the outer surface of the 
receptacle is formed only in peripheral portions so that in the gaps 
therebetween, the arresting elements for the form-locking operative 
connection with the inner undercut of the ejection cylinder are formed. 
When the gripping strip is designed in accordance with the present 
invention, it is formed as a one-piece part which is produced in a single 
process. The gripping part is very simply mountable by manual placing of 
the syringe cylinder onto the whole cylindrical receptacle and insertion 
of the safety ring. The gripping strip requires relatively little 
synthetic plastic material, which is very favorable for its disposal and 
the manufacturing costs. 
In accordance with a further feature of the present invention, the 
arresting elements are formed by hook-shaped arresting tongues which allow 
a simple and thereby reliable connection. 
An especially durable seat of the safety ring in accordance with the 
present invention is possible when connecting elements are formed on the 
receptacle and on the safety ring for a snap connection so that the safety 
ring is movable from the secure position only in a breaking manner. 
Preferably, the gripping part is formed as an injection molded part and 
composed of a thermoplastic material, for example polyolefin 
(polypropylene, polyethylene), but preferably of polycarbonate (PC) or 
polyoxymethylene (POM). 
Preferably, in the gaps between the peripheral portions from the outer 
surface of the receptacle, the connecting elements are formed for the snap 
connection with the safety ring. This embodiment is also material-saving 
and provides a fixed connection of the safety ring. 
An especially favorable handling of the syringe, in which no slippage of 
the finger occurs on the gripping strip during application as well as a 
further material saving is possible, is achieved when in accordance with a 
second embodiment of the invention, a grate structure is formed in the 
flange-like abutment and is open at the side facing the syringe cylinder. 
The novel features which are considered as characteristic for the present 
invention are set forth in particular in the appended claims. The 
invention itself, however, both as to its construction and its method of 
operation, together with additional objects and advantages thereof, will 
be best understood from the following description of specific embodiments 
when read in connection with the accompanying drawings.

DESCRIPTION OF PREFERRED EMBODIMENTS 
The drawings show a gripping strip for prefilled disposable syringes, which 
is fixedly mounted on a syringe cylinder (not shown) and in particular on 
its one end as a separate synthetic plastic part. The gripping strip has a 
plate-shape abutment I with a hollow cylindrical receptacle 2 for mounting 
with the syringe cylinder. The outer diameter of the receptacle 2 is 
smaller than the inner diameter of the syringe cylinder, so that the 
gripping strip is mountable in the interior of the syringe cylinder and 
thereby does not form an outwardly projecting edge. 
As can be seen from FIG. 1, in the shown embodiment of the disposable 
syringe, the outer surface of the receptacle 2 is not a continuous 
surface, but instead is formed substantially in three peripheral portions. 
They are identified with reference numerals 2. Peripheral arresting 
elements 3 are formed in the gaps between the peripheral portions. In the 
shown embodiments, there are four arresting elements for a form-locking 
operative connection with an edge-side inner ring collar (undercut) of the 
syringe cylinder. The arresting elements simultaneously perform a guiding 
function for the syringe cylinder in the gaps of the peripheral portions 2 
of the outer surface of the receptacle. The arresting elements 3 in the 
shown embodiment are formed as, hook-shaped arresting tongues. They allow 
an especially simple clamping of the syringe cylinder and operate so that 
the gripping strip can withstand high pulling forces. 
The gripping strip in accordance with FIG. 1 further has a safety ring 4. 
The safety ring is mountable in the interior of the receptacle 2 for 
maintaining the operative connection between the peripheral arresting 
elements 3 and the edge-side inner collar of the syringe cylinder. This 
safety ring, as in particular can be seen from FIG. 2, is connected of one 
piece with the interior of the receptacle 2 through points of desired 
breakage 5 in a unsecured position of FIG. 2. During the placing of the 
syringe cylinder over the receptacle 2, the points of desired breakage 5 
break through and the safety ring is displaced into the secure position 
into the interior of the receptacle, and in particular to the abutment 2a 
on three receiving portions 2. For blocking the safety ring in this 
securing position, three connecting elements shaped as arresting tongues 3 
are formed for a snap connection with a corresponding counter piece on the 
safety ring 4. Therefore, the safety ring is movable from the securing 
position only when it is destroyed. The snap connecting elements 6, 
similarly to the arresting tongues 3, are formed in the gaps between the 
peripheral portions of the outer surface of the receptacle. 
In accordance with the shown embodiment of the inventive gripping strip, 
the plate-shaped abutment 1 is formed for example with a grate structure 
7. The grate structure is open at the side which faces the syringe 
cylinder, or in other words at the side on which the finger abuts. Thereby 
the finger of the operator during application obtains a particularly 
gripping and thereby a reliable abutment against the gripping strip and 
can not slide from the plate-shaped abutment. 
It will be understood that each of the elements described above, or two or 
more together, may also find a useful application in other types of 
constructions differing from the types described above. 
While the invention has been illustrated and described as embodied in 
gripping strip for prefilled disposable syringes, it is not intended to be 
limited to the details shown, since various modifications and structural 
changes may be made without departing in any way from the spirit of the 
present invention. 
Without further analysis, the foregoing will so fully reveal the gist of 
the present invention that others can, by applying current knowledge, 
readily adapt it for various applications without omitting features that, 
from the standpoint of prior art, fairly constitute essential 
characteristics of the generic or specific aspects of this invention.