Method for manufacturing a check valve contained within a tube

A check valve integral with the tube and the method of manufacturing a check valve are disclosed. The ball or poppet of the check valve is maintained in position via a magnetic mandrel while the tube is crimped at both sides of the poppet. The tube is inwardly crimped to prevent the poppet from being displaced in either direction and simultaneously to allow flow to bypass the poppet in the desired flow direction. Thereafter the poppet is physically displaced against one of the crimped indentations to coin a seat such that the poppet and the seat coact to prevent flow of fluid in the undesired direction. In this manner, a check valve is formed integrally with a tube without requiring any additional components.

BACKGROUND OF THE INVENTION 
This invention relates to a ball-type check valve formed integrally with a 
tube and a method of manufacturing the check valve. More specifically, 
this invention concerns crimping the tube while a ball or poppet is 
secured in position to form a check valve integral with a tube. 
In many applications it is desirable to incorporate a check valve in a 
fluid flow line to prevent fluid from flowing in one direction while 
allowing fluid to flow in the other direction. In those applications where 
a check valve may be incorporated directly in the fluid line, the 
necessity of using self-contained separate valve assemblies that must be 
joined in an appropriate manner to the tubing or pipe system is avoided. 
Additionally, by using an integral valve with tubing, if this tubing is a 
subassembly for a larger assembly then assembly time and labor required 
may be reduced since the subassembly including the tubing additionally 
incorporates the check valve. This eliminates the need to assemble a 
separate valve at the same time. Hence, both the material of the separate 
valve and the labor to install a separate check valve may be reduced by 
incorporating the check valve integrally with the tubing. 
Heretofore, integrally assembled check valves have required a cage assembly 
and sealing means such that the-ball of the check valve is maintained 
within the cage and the sealing means acts to secure the cage within the 
tube and secures the sealing means in the tube to prevent flow 
therebetween. The sealing means may additionally define a seat for the 
ball to provide a seal therebetween to prevent flow in the unwanted 
direction. 
SUMMARY OF THE INVENTION 
The invention described herein incorporates a poppet directly into a fluid 
conducting tube and repositions the wall of the tube to both retain the 
poppet in position and to provide a seal for effecting check valve 
operation. All this is accomplished without the use of any material other 
than the tube wall being appropriately deformed. No valve cage or other 
additional structures need be utilized. A simple insertion of the poppet 
itself and the subsequent deformation of the tube wall are all the 
components necessary to form the check valve. 
One of the objects of the herein invention is to provide a check valve 
integral with a tube. 
A further object of the present invention is to provide a simple, 
inexpensive check valve which may be incorporated integrally with a 
fluid-carrying tube. 
A further object of the present invention is to provide a simple, 
economical method of manufacturing a check valve integral with a tube. 
A still further object of the present invention is to provide a method of 
manufacturing a check valve including magnetically positioning a poppet 
and deforming the walls of the tube about the poppet to form the valve 
retaining surfaces. 
It is a yet further object of the present invention to provide a safe, 
economical, reliable, and easy to manufacture check valve which is 
integral with a tube. 
Other objects will be apparent from the description to follow and the 
appended claims. 
The above objects are achieved according to the preferred embodiment by the 
provision of a check valve integral with a tube including a poppet secured 
within the tube by a seat indentation formed by displacing a 
circumferential portion of the tube radially inwardly and a retaining 
indentation including a series of spaced inwardly extending retaining 
indentations whereby the retaining indentations secure the poppet from 
displacement in one direction while allowing fluid flow around the poppet 
through the tube and the seat indentations secure the poppet from 
displacement in the opposite direction and together with the poppet 
substantially limit flow of the fluid in the opposite direction. 
A method of making a check valve integral with a tube is further disclosed. 
The method includes the steps of positioning a poppet within the tube, 
crimping the tube on one side of the poppet to form a seat indentation for 
limiting motion of the poppet and crimping the tube on the other side of 
the poppet to form a retaining projection for limiting motion of the 
poppet without unduly limiting flow through the tube. The method further 
includes magnetically positioning the poppet before crimping occurs on 
either side of the poppet and subsequent coining of the seat for the 
poppet by striking the poppet with a punch to effectively displace a 
portion of the seat indentation to form a seat surface.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The check valve and method of manufacture thereof will be described with 
reference to the drawings herein. It is to be understood that this method 
and check valve may be utilized with additional components. For instance, 
a seal might be attached to the poppet before insertion within the tube 
and secured magnetically in place with the poppet prior to crimping such 
that a seal would be positioned within the tube. Additionally, the number 
and positioning of the fingers of the radial crimper are dependent upon 
the specific tube size and design involved. Furthermore, the poppet could 
be bullet-shaped or some other configuration capable of forming a seal 
with the seal surface. 
Referring first to FIG. 1, there may be seen a tube 10 which initially is 
generally cylindrical in configuration. Inserted within tube 10 is 
magnetic mandrel 20 having base 22 which abuts against the end of tube 10. 
Magnetic mandrel 20 additionally includes extension 24 extending 
internally within the tube and having magnetic portion 26 attached to the 
end of extension 24. Poppet 30 which is a spherical member which serves to 
perform the checking function of the check valve is magnetically secured 
to the end of the magnetic mandrel in the desired position. 
The entire assembly may then be located within the central opening of 
radial crimper 80 as is shown in FIG. 4. Central opening 84 is located at 
the center of the crimper such that a tube inserted therewithin may be 
engaged by various crimper fingers 50 and 60 and be displaced inwardly. 
Crimper finger B labeled 50 as shown in FIG. 1 is shown having a seat 
projection 52 and a retaining projection 54. It will be noted that seat 
projection 52 is generally rounded forming a rounded preseat indentation 
12 in the tube when used to crimp the tube. Retaining projection 54 
extending from finger B is generally pointed and forms a pointed retaining 
indentation 14 extending into the tube. 
Additionally, as may be seen in FIG. 1, poppet 30 is prevented from 
displacement to the left by the preseat indentation 12 and from 
displacement to the right by retaining indentation 14. 
Referring to FIGS. 2 and 3, which are sectional views of the tube taken at 
lines 2--2 and 3--3 of FIG. 1, the specific geometry of the tube may be 
seen. As shown in FIGS. 2 and 4, it may be seen that there are eight 
preseat indentations 12 spaced about the tube and extending inwardly 
therefrom. These projections are spaced circumferentially about the tube 
and act to define a generally inwardly extending radial surface. 
On the other hand, the cross section taken at line 3--3 shows retaining 
indentations 14 which are spaced about the tube leaving an opening 
therebetween. Tube 10 is shown defining a bypass area 19 between inwardly 
extending retaining indentations 14. Poppet 30 has been shown via a dotted 
line to show its relative position such that it may be seen that when the 
poppet is displaced against the retaining indentations 14 bypass area 19 
is formed to allow fluid flow to bypass the poppet and flow through the 
tube. 
Referring specifically to FIG. 4 it may be seen that crimper 80 has a 
housing 82 and a series of crimper fingers 50 and 60 spaced for radial 
displacement within the housing. These crimper fingers are activated by an 
annular striker mechanism which rotates within the housing and forces the 
crimper fingers inwardly to provide the appropriate indentations in the 
tube surface. It will be additionally appreciated from FIG. 4 that fingers 
A and B referenced as fingers 60 and 50 respectively are spaced 
alternatingly about the radial crimper such that each finger is spaced 
from the other by the other type of finger. Finger A referenced by numeral 
60 is shown in FIG. 5 and has but a single seat projection labeled 62 
which is indentical to seat projection 52 of finger B. Finger B as shown 
in FIG. 6 and labeled 50 includes, in addition to seat projection 52, 
retaining projection 54. Hence, as spaced about the radial crimper, it 
will be obvious that all eight fingers as shown include a seat projection 
labeled either 52 or 62 which acts to form the seat indentation at all 
eight locations as shown in cross section of FIG. 2. On the other hand, 
the retaining projection 54 is located only on the alternating finger B 
referenced by numeral 50 such that the retaining indentations are formed 
only by every other finger and hence there are only four retaining 
indentations spaced about the tube as may be seen in FIG. 3. Additionally, 
these indentations are more pointed and are spaced apart to define bypass 
area 19. 
Once the tube has been crimped in the manner indicated, the poppet is 
prevented from being displaced from its desired position. However, the 
preseat indentations 12 when coacting with the surface of poppet 30 are 
such that they do not substantially act to limit flow from right to left 
direction looking at FIG. 1. Referring now to FIG. 7, it may be seen that 
punch 90 is provided to effectively displace the poppet to the left 
forming a contact point 32 between the poppet and the preseat indentation 
to define a seat indentation 15 having a seat surface 16. By the physical 
displacement of the poppet into the preseat indentation, the indentation 
is deformed into seat indentation 15 defining a seat surface 16. Seat 
surface 16 acts to engage the exterior surface of poppet 30 at contact 
point 32 to define a seal therebetween for substantially limiting flow 
from the right to left direction as shown. Punch 90 includes an extension 
92 which physically contacts the poppet to effect displacement. 
FIG. 8 is a cross-sectional view taken along line 8--8 in FIG. 7 and shows 
the relationship between the components. It may be seen therein that seat 
indentation 15 still extends slightly inwardly from seat surface 16. 
However, it is seat surface 16 which coacts with the exterior surface of 
the poppet to define the seal therebetween. 
The tube and poppet assembly shown in FIG. 7 is labeled as check valve 100. 
This is the final assembly wherein the retaining projection is formed to 
prevent displacement of the poppet to the right while allowing flow of 
fluid through the tube to the right and wherein seat surface 16 prevents 
displacement of the poppet to the left and upon fluid flow being in the 
right to left direction acts to provide a seal surface which mates with 
the poppet to substantially limit fluid flow from the right to the left. 
The invention has been described with reference to a particular embodiment 
and a particular method of manufacture. It is to be understood by those 
skilled in the art that variations and modifications can be effected 
within the spirit and scope of the invention.