JPH0228033B2 - - Google Patents

Abstract

A tubular ring is formed from a suitable rubber like material. A circumferential slit 18 is formed on the periphery of the ring which communicates with the bore in the ring. Then the sides of the slit are spread apart far enough so a garter spring 22 can be inserted through the slit into the bore of the ring. The garter spring 22 is sized so it is movably mounted in the bore of the ring so it can exert the required compressive force on the finished seal. The sides of the slit are then cemented together and a fiberglass cloth 24 is cemented to the inner surface 28 of the ring to form a work contacting surface on the seal. <IMAGE>

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of forming a ring-shaped seal with a garter spring movably mounted in a vertical hole located in the center of the seal.

B. Structure of the invention A tubular ring is made from a suitable rubber-like material. A circumferential slit communicating with the vertical hole of this ring is made on the outer periphery of this ring. The sides of the slit are then widened sufficiently to allow the garter spring to be inserted through the slit and into the longitudinal hole of the ring. The garter spring is movably mounted within the ring well and is sized to exert the compressive force necessary for the completed seal. The sides of the slit are then glued together and a fiberglass cloth is glued to the inner surface of the ring to form the work contacting surface of the seal.

C. Prior Art and Problems As described in more detail in U.S. Pat. No. 4,453,723, an aircraft uses a ring-shaped rubber seal having a garter spring movably mounted within a vertical hole located in the center of the seal. It is necessary that the well and the garter spring be in a remote relationship with the internal workpiece contacting surface of the seal. This arrangement will increase the useful life of the seal.

However, traditional seal-forming methods are
As noted in No. 4,453,723, the tolerances and physical properties of the finished seal were unsatisfactory because they were not uniform enough.

A conventional seal forming method is described in U.S. Patent No. 4,453,723.
As mentioned in the above issue, it required a tubular semi-cured rubber or rubbery insert to be formed in a conventional extruder. This insert was cut to the required length. Next, a garter spring, also cut to the required length, was inserted into the vertical hole of the insert. The ends of the garter spring are ring shaped with the garter spring movably mounted within the longitudinal bore of the tubular ring, the ends being designed to allow them to be joined together in a manner well known in the art. An insert was formed.

A layer of silicone-impregnated fiberglass cloth was then inserted into the mold cavity. The ring-shaped tubular insert was then placed on top of the fiberglass cloth. A ring-shaped piece of uncured rubber was then inserted into the mold cavity and the mold was closed. Finally, the mold was placed in an oven long enough to cure the rubber and create a seal.

This method is unsatisfactory because during the curing process, contrary to expectations, the semi-cured rubber insert shrinks around the garter spring in an indiscriminate manner, so that the garter spring cannot necessarily move freely within the wells of this seal. It wasn't. Therefore, seals made by this method did not have uniform performance characteristics.

D. OBJECTS OF THE INVENTION What is needed, therefore, and which comprises an important object of the present invention, is a method of forming a seal with a garter spring movably mounted within a vertical hole located centrally in the seal. The object of the present invention is to provide a method for producing seals that are easy to implement and have uniform performance characteristics.

These and other objects of the invention will become more apparent when better understood with reference to the following description and drawings.

EXAMPLE 1 Referring to FIG. 1, a rubber-like material suitable for sealing is extruded in the cured state into tubular shapes by any conventional apparatus and cut to the appropriate length. Next, adhesive is applied to both ends 12 of each book material 10, and these are joined to form a tubular ring 10 with a vertical hole 20 formed in the center (see FIG. 2).

Next, this ring is attached to the power-driven rotating spindle 1.
4 and a circumferential slit 18 communicating with the vertical hole 20.
The knife 15 is pressed against the outer periphery 16 of this ring 10 until it forms (see FIGS. 3 and 4). Thereafter, the side surface of the slit 18 is opened, and a ring-shaped garter spring 22 of an appropriate shape is inserted through the open side surface of the slit 18 (see FIGS. 5 and 6).
The garter spring 22 is sized so that each turn of the garter spring does not stick to the wall of the well 20 so that it can move independently of the seal body when it is in the well 20. It's summery.
In addition, the diameter of the garter spring is such that when it is in the ring well, the completed seal has a temperature range over a wide temperature range to compensate for the loss of elasticity of the elastomeric material forming the seal over a wide temperature range. It is chosen so that an appropriate compressive force can be applied to the ring independently of the ring.

Next, one or more layers of ring-shaped silicone-impregnated fiberglass cloth 24 are inserted into the mold cavity of section 30 (see FIG. 7). Then, the ring 10 with the garter spring movably attached in the vertical hole 20 is attached to the mold part 30 so that the glass fiber cloth 24 faces and abuts the inner surface 28 of the ring 10.

Next, a heat-reactive adhesive is applied to the sides of the slit 18 and the inner surface of the ring 10. Thereafter, the glass fiber cloth is cut to an appropriate length, and the mold part 46 is placed over the mold part 30 (see FIG. 7). The mold is then placed in an oven, which firmly adheres the opposing sides of the slits 18 together and adheres the fiberglass cloth 24 to the inner surface 28 of the ring to form the work-contacting surface of the seal. (See Figure 10). In this arrangement, the garter spring 22 is inserted into the well 20 after the rubber-like material that makes up the ring 10 is in a "hardened" state, so that the garter spring does not stick to the inner wall of the seal well. right.

As seen in Figure 7. Each mold is made of two mating parts. The first consists of a mold part 30 having a generally cylindrical base part 31 and a centrally arranged cylindrical part 33 extending upward from this base part (see FIGS. 7 and 8). ).
Although this overlying cylindrical portion has a smaller diameter than the base portion 31 in this particular example, other configurations are also contemplated where the reverse is true. The outer periphery 35 of the overlying cylindrical portion 33 is generally concave and in this embodiment serves to completely define the inner surface of the seal that ultimately engages the sealing surface of the duct or connector. This arrangement is important because the entire internal workpiece contacting surface of the seal 10 is made from the face 35 of the mold section 30. This prevents "burrs" from forming on the internal workpiece contacting surfaces of the seal.

The second part of the mold consists of a ring-shaped mold section 46 containing a hole 47 and a borehole 48 (see FIGS. 7 and 9). Portions 30 and 46 are in assembled relationship;
Form a complete mold for one seal (see Figure 8).

In order to combine the mold parts 30 and 46, the mold part 30
is a positioning surface 54 arranged on the outer periphery of one circle.
and 56 (see FIG. 7). In addition to serving as a locating surface for mold section 46, surface 54 also serves as the base of this mold cavity (see FIG. 7). The mold part 46 rests on the mold part 30 and together forms a mold cavity 61 (see FIG. 9). The hole 48 of the mold part 46 is
on the diameter of one circle and on the surface 54 of the mold part 30
and 56 to maintain the connection of the portions 30 and 46.

In stacked relationship, the lower surface 58 of the mold section 30 is
It is located on the upper surface 59 of the mold part 46. This closes the mold cavity 61 so that a seal can be formed when these molds are placed in an oven (see Figure 8). The outer periphery 49 of the hole 47 in the mold section 46 is concave in this embodiment and completely defines the entire outer surface 13 remote from the internal workpiece contacting surface of the seal (see FIG. 8). Therefore, no burrs can form on this external workpiece contact surface. This removal of burr formation reduces the effort required to finish the seal.
In assembled relation, with mold section 46 overlying mold section 30, concave surfaces 35 and 49 face each other to define the outer circumferential limits of mold cavity 61 (see FIG. 8).

Multiple molds, each including mold section 46 and mold section 30, can be stacked on upright support 44 (see FIG. 9) so that multiple seals can be formed simultaneously. A closure member 60 with a support receiving hole 62 arranged in the center rests on this mold mound.
This part has a shape similar to the surface 58 of the mold part 30,
The mold has a lower surface 64 that closes the mold cavity 61 at the top of the mold pile.

Alternative methods of seal formation using the general principles of the present invention may be more suitable for small diameter seals. In this method, the mold is designed to form a tubular ring with a central longitudinal hole, which ring defines a circumferential slit communicating with the longitudinal hole. When the ring leaves the first mold, the tubular rubber ring is in a cured state. At this point, a suitably shaped garter spring is inserted into the longitudinal bore of the tubular ring 10 through the open side of the slit. The garter spring 22 is sized such that when it is in the well 20 of the seal 10, each turn of the garter spring does not adhere to the face of the well, so that the garter spring The seal is movably mounted within the longitudinal bore of the seal and provides temperature-independent sealing engagement with the surface of the aircraft duct over a wide temperature range to compensate for the aging loss of elasticity of the elastomeric material forming the seal. A compressive force suitable for the seal can be applied to the seal.

Adhesive is then applied to the faces of the tubular ring facing the slits and to the inner surface of the ring. The ring is then placed in a second mold having appropriately shaped ring-shaped fiberglass cloth layers disposed in the mold so that they contact the inner surface of the ring. When the mold is closed and inserted into an oven, heat joins the opposing sides of the slit and bonds the fiberglass cloth to the inner surface of the ring to create the finished seal.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the rubber tubular material from which the seal is made, cut to length after it exits the extruder, showing the central longitudinal hole made in the material. Second
The figure shows a rubber tube joined at both ends to form an "O-ring". FIG. 3 shows a ring-shaped seal mounted on a rotating spindle and a knife blade advanced to cut a circumferential slit in the seal leading to a longitudinal hole in the seal. FIG. 4 is an enlarged cross-sectional view of the seal showing the slit leading to the vertical hole in the seal. FIG. 5 shows the seal shown in FIG. 4 after the slit sides of the seal have been opened and a ring-shaped garter spring has been inserted into the longitudinal hole. FIG. 6 is a cross-sectional view of the seal shown in FIG. 5 taken along line 6--6. FIG. 7 is an exploded cross-sectional view of a mold with a seal installed over one or more layers of fiberglass fabric within the mold cavity. FIG. 8 is a view of the two parts of the mold shown in FIG. 7 in assembled relation and the seal placed in the mold cavity. FIG. 9 shows the molds stacked on top of each other so that multiple seals can be made simultaneously. Figure 10 and 1
Figure 1 is an enlarged cross-sectional view of the completed seal.
The figure shows a modified cross-section seal made with a suitably shaped mold. 10... Tubular ring, 12... End, 18... Slit, 20... Vertical hole, 22... Garter spring,
24...Glass fiber cloth, 28...Inner surface.

Claims (1)

Claims: 1. Cut a tube of "cured" elastomeric material to size, then apply adhesive to each end 12 of this length of material and join them together with a longitudinal hole in the center. forming a tubular ring 10 with 20 and then cutting a circumferential slit 18 in the outer periphery of this ring of sufficient depth to pass through the longitudinal hole in the ring;
A garter spring 22 is then selected, and the sides of the slit in the ring are widened sufficiently to allow the garter spring to be inserted into the well of the ring, and each turn of the garter spring is sized so that each turn of the garter spring is against the wall of the well. The diameter of this garter spring was chosen such that it could be retracted independently of the ring so that it could be retracted independently of the ring so that it could be movably mounted in the well of this ring. When the garter spring is selected to be able to exert a temperature-independent compressive force on the ring over a wide temperature range for an extended period of time, the opposite sides of the slits are then glued together and the inner surface 2 of the ring is
A method of forming a seal comprising the steps of applying adhesive to ring 8 and finally adhering a glass fiber cloth 24 to the inner surface of the ring to form the workpiece contacting surface of the seal. 2. A tubular ring 10 is formed from a tubular "hardened" rubber-like material, which ring has a circumferential slit 18 on the outer circumference of the ring leading to a longitudinal hole 20 in the tubular ring.
, and then push the sides of this slit open enough to allow the garter spring 22 to be inserted into the longitudinal hole of this ring, the size of each turn of this garter spring being:
Each turn of this garter spring is chosen so that it does not stick to the wall of the well of the tubular ring, so that this garter spring can be contracted independently of the ring, and the diameter of this garter spring is such that it is inside the well of this ring. The garter spring is chosen so that it can exert a temperature-independent compressive force on the ring over a wide temperature range over an extended period of time, when movably mounted on the opposite sides of the slit and on the inner surface 28 of the ring. The opposite sides of the slits are glued to each other with adhesive, and finally a suitably shaped glass fiber cloth 24 is applied to this inner surface of the ring, whereby the glass fiber cloth is glued to the inner surface of the ring and the ring is completed. A method for forming a seal including steps of forming a workpiece contacting surface of the seal. 3 Select a tubular length of "cured" silicone-impregnated rubber, then apply adhesive to both ends 12 of the tubular rubber and glue the ends of the tubular rubber together to form a ring 10 with a longitudinal hole 20 in the center. Making,
Then cut a circumferential slit 18 deep enough on the outer circumference of this ring to communicate with the vertical hole of this ring, then press open the sides of this slit and insert the garter spring 22 into the vertical hole. The size of each turn of the garter spring is chosen such that each turn of the garter spring does not stick to the wall of the well of the tubular ring, so that the garter spring can be contracted independently of the ring, and the diameter of the garter spring is The garter spring is chosen so that, when it is movably mounted within the well of this ring, it can exert a compressive force on the ring over a wide temperature range for long periods of time, independent of temperature, and then the slit and the inner surface 28 of the ring, and then inserting the ring into a mold having one or more fiberglass fabric layers 24 in contact with the inner surface of the ring within the mold. , the mold is then closed and the ring is cured in an oven so that the sides of the slits adhere to each other and the fiberglass cloth covering the inner surface of the ring adheres to the inner surface of the ring to seal the workpiece contacting surface of the seal. A seal forming method including each step of forming a seal.