FIELD OF INVENTION
The present invention relates a joint block. More specifically, the present invention relates to a joint block for use in a Thermal Expansion Valve (TXV) assembly of an air conditioning system.
BACKGROUND OF THE INVENTION
The air conditioning systems industry as well as the automotive sector need to continually innovate to reduce the weight, cost, and manufacturing time of parts, while maintaining the same specifications.
For example, in the air conditioning systems industry, the reduction in manufacturing time and cost of several components, such as joints, pipes, hoses, etc., leads to significant reduction in cost of manufacturing the end products, such as automotive air conditioning system, and which further leads to a significant competitive cost advantage in the market. The benefit of reduced manufacturing costs can also be transferred to end consumers by lowering the prices of end products.
Further, the automobile sector is constantly working towards fuel efficiency innovations; and reduction in weight of a number of small components, such as joints, pipes, hoses, etc. in an automotive air conditioning system, can collectively lead to significant weight reduction and improvement in a vehicle's fuel efficiency. The increased fuel efficiency can further reduce the cost of owning a vehicle of the end user.
Therefore, there is a constant need to reduce the weight, cost, and manufacturing time of parts while maintaining their desired specifications.
The present invention proposes an alternative to an aluminium joint block, used in the air conditioner systems, which is not only cost effective to manufacture but is also considerably less in weight.

OBJECTIVES OF THE INVENTION
The main objective of this invention is provide a joint block for use in a Thermal Expansion Valve (TXV) assembly in an air conditioning system.
Another objective of this invention is to provide a joint block that has a reduced weight.
Another objective of this invention is to provide a joint block that has a reduced cost of manufacturing.
Another objective of this invention is to provide a joint block that has a reduced time of manufacturing.
SUMMARY OF THE INVENTION
The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the present invention. It is not intended to identify the key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concept of the invention in a simplified form as a prelude to a more detailed description of the invention presented later. Aspects of the present disclosure includes a joint block for use in a thermal expansion valve (TXV) assembly of an air conditioning system. The joint block includes a body (11, 101, 201) having an aperture (12, 102, 202) for fitting a gas suction pipe connected to the TXV assembly, an aperture (16, 106, 206) for fitting a liquid pipe connected to the TXV assembly, and an aperture (14, 104, 204) for fitting a bolt for connecting the joint block to the TXV assembly. The body is made of a glass filled polymer.
In some aspects, the glass filled polymer includes nylon 6 with a glass composition ranging between 30% and 50%. In some further aspects, the glass filled polymer includes glass filled nylon 6 with a glass composition of 40%.

In some aspects, the joint block includes an insert, and wherein the insert includes the aperture for fitting the bolt.
In some aspects, the aperture for fitting the gas suction pipe include a side opening to allow the gas suction pipe to slide into the aperture.
In some aspects, the aperture for fitting the liquid pipe includes a side opening to allow the liquid pipe to slide into the aperture.
In some aspects, the joint block includes an insert, wherein the insert includes an aperture across the longitudinal axis for fitting the bolt, and a depression positioned along an outer circumferential surface of the insert. In some further aspects, the outer circumferential surface of the insert includes one or more protrusions or ridges, is knurled, or is roughened.
Aspects of the present disclosure also describe a method of manufacturing the joint block described above, wherein the method includes steps of injecting glass filled plastic in a mold, cooling the mold, ejecting the formed joint block from the mold; and finishing the joint block. In some aspects, the method also includes a step of placing an insert in the mold before injecting glass filled plastic in the mold.
Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
Some of the objects of the invention have been set forth above. These and other objects, features, aspects and advantages of the present invention will become better understood with regard to the following description, appended claims and accompanying drawings where:

Figures 1A-1B is a illustrate a first embodiment of a joint block, where Figure 1A is a schematic front view of the joint block, and Figure IB is a schematic cross-section view of the joint block;
Figures 2A-2B is a illustrate a second embodiment of a joint block, where Figure 2A is a schematic front view of the joint block, and Figure 2B is a schematic cross-section view of the joint block;
Figure 3A-3B illustrate an insert of the second embodiment of a joint block as shown in Figure 2A-2B, where Figure 3A is a schematic top view of the insert, and Figure 3B is a schematic front view of the insert;
Figures 4A-4B is a illustrate a second embodiment of a joint block, where Figure 4A is a schematic front view of the joint block, and Figure 4B is a schematic cross-section view of the first embodiment of the cross-section block;
Figure 5 is a schematic illustrating the second embodiment of the joint block shown in Figures 2A-2B positioned in a thermal expansion valve (TXV) assembly.
DETAILED DESCRIPTION
The following detailed description should be read with reference to the drawings in which similar elements in different drawings are numbered the same. The drawings, which are not necessarily to scale, depict illustrative embodiments and are not intended to limit the scope of the invention. Although examples of construction, dimensions, and materials are illustrated for various elements, those skilled in the art will recognize that many of the examples provided have suitable alternatives that may be utilized.
A joint block is used for joining gas suction pipe and liquid pipe with thermal expansion valve (referred to hereinafter as, TXV) in air conditioning systems, such as automotive air conditioning systems. Existing joint blocks are usually made with aluminium by extrusion and machining process fixed by brazing. The

present invention presents a joint block made of composite materials that provides the desired specification with a reduced weight. In addition, the manufacturing time and cost of the joint block of the present invention is also lower than a conventional aluminium joint block.
In a first embodiment, the joint block of the present invention includes a body made of a glass filled plastic. The body includes three apertures, a first aperture for fitting a gas suction pipe, a second aperture for fitting a bolt, and a third aperture for fitting a liquid pipe. The aperture for fitting the liquid pipe includes a side opening to allow for sliding the liquid pipe in the aperture. In a second embodiment of the invention, the joint block includes an insert, the insert has the aperture for fitting the bolt. The insert reduces the compressive stress on the body when a bolt is tightened in the aperture for fitting the bolt to hold the joint block in place on the TXV. In a third embodiment of the invention, the aperture for fitting the gas suction pipe includes a side opening to allow for sliding the gas suction pipe in the aperture.
The following paragraphs describe the embodiments in details:
Figures 1A-1B is a illustrate a first embodiment of a joint block 10, where Figure 1A is a schematic front view of the joint block 10, and Figure IB is a schematic cross-section view of the joint block 10. The joint block 10 includes a body 11 having an aperture 12 for fitting a gas suction pipe, an aperture 14 for fitting a bolt, and an aperture 16 for fitting a liquid pipe. The aperture 16 includes a side opening 18 to allow for sliding the liquid pipe in the aperture 16.
Figures 2A-2B is a illustrate a second embodiment of a joint block 100, where Figure 2A is a schematic front view of the joint block 100, and Figure 2B is a schematic cross-section view of the joint block 100;
The second embodiment of the joint block 100, similar to the first embodiment, includes a body 101 having an aperture 102 for fitting a gas suction pipe, an aperture 106 for fitting a liquid pipe. Similarly, the aperture 106 includes a side opening 108 to allow for sliding the liquid pipe in the aperture 106.

The joint block 100 also includes an insert 110 positioned along the body 101. The insert 110 include an aperture 104 for fitting a bolt. The insert 110 is made of a higher tensile and compressive strength material than the body 101 and is bonded to the body 101. The insert 110 reduces the compressive stress on the body 101 when a bolt is tightened in the aperture 104 to hold the joint block 100 in place on a TXV. In some embodiments, the insert 110 can be a generic insert available off-the shelf, or in some embodiments, the insert 110 can be specifically designed to reduce bolt tightening stress on the joint block 100, as disclosed in Figures 3A-3B below.
Figure 3A-3B illustrate a specifically designed insert 110 of the joint block 100, where Figure 3A is a schematic top view of the insert, and Figure 3B is a schematic front view of the insert. As shown, the insert 110 includes a depression 112 positioned along an outer circumferential surface 111 of the insert 110. Further, the outer circumferential surface 111 of the insert 110 is roughened, knurled, or includes one or more protrusions or ridges to increase frictional bonding of the insert 110 with the body 101 of the joint block 100.
Figures 4A-4B is a illustrate a third embodiment of a joint block 200, where Figure 4A is a schematic front view of the joint block, and Figure 4B is a schematic cross-section view of the first embodiment of the cross-section block. The third embodiment of the joint block 200, is similar to the joint block 100 (second embodiment) in configuration, size and materials of construction. The joint block 200 includes a body 201, the insert 210, an aperture 202 for a gas suction pipe, an aperture 204 for a bolt, and an aperture 206 for a liquid pipe. The insert 210 (referring to Figures 4B) includes the aperture 204, and has a depression 212 on its outer circumferential surface 211, which is roughened, knurled, or includes one or more protrusions or ridges to increase frictional bonding of the insert 210 with the body 201 of the joint block 200. However, unlike the second embodiment, in the third embodiment, i.e. joint block 200, the aperture 202 has a side opening 208 to allow for sliding the gas suction pipe in the aperture 202.

The following section describes exemplary materials of construction of the above described embodiments (refer to Figures 1A-1B, 2A-2B, 3A-3B, and 4A-4B):
The body 11, body 101, and body 201 of the joint block 10, joint block 100, and joint block 200 respectively can be made of any composite material. In some 5 embodiments, the body 11, body 101, and body 201 are made of a glass filled plastic, such as nylon 6, with a concentration of the glass filling ranging from 30% to 50%, more preferably, from 35% to 45%. In some embodiments, the concentration of glass in nylon 6 is 40%.
The insert 110 and insert 210 are made of a material that can take high 10 compressive loads, for example, in some embodiments, the insert 110 and insert 210 are made of a metal or a metal alloys. In some embodiments, the insert 110 and insert 210 are made of mild steel, stainless steel, aluminium, or an aluminium alloy. In some embodiments, the insert 110 and insert 210 are made of high strength carbon fibre.
15 The following section describes exemplary sizes of various features of the above joint blocks 10, 100, and 200 respectively (refer to Figures 1A-1B, 2A-2B, 3A-3B, and 4A-4B):
The size of the joint blocks 10, 100, and 200 depends on the size of the gas suction pipe, the liquid pipe, the bolt, and the TXV in a TXV assembly where it is
20 to be used. In some embodiments, each of the joint blocks 10, 100, and 200 have a length ranging between a 40-80 mm, width ranging between 20-40 mm, and a height ranging between 5-40 mm. The distance between the centres of apertures 12 and 14, apertures 102 and 104, apertures 202 and 204 ranges between 10-40 mm, and distance between the centres of apertures 14 and 16, apertures 104 and
25 106, apertures 204 and 206, ranges between 10-40 mm. The radius of apertures 12, 102, and 202 ranges between 4-10 mm, the radius of apertures 14, 104, and 204 ranges between 5-10 mm, and the radius of apertures 16, 106, and 206 ranges between 4-15 mm. The width of the side openings 18 and 108 ranges between 5-15 mm. The width of the side opening 208 ranges between 16-25 mm.
8

In some embodiments, the inserts 110 and 210 have a height same as the height of the joint blocks 100 and 200 respectively, ranging between 5-40 mm, and an outer circumferential radius ranging between 3-15 mm. The depressions 112 and 212 have a radius ranging between 2-10 mm, a height ranging between 3-36 mm, and 5 a depth ranging between 1-2 mm.
The following section describes exemplary manufacturing methods of the above described embodiments of the joint blocks 10, 100, and 200 (refer to Figures 1A-1B, 2A-2B, 3A-3B, and 4A-4B):
The bodies 11, 101, and 201 of the joint blocks 10, 100, and 200 respectively can 10 be manufactured by any plastic molding process known in the art. In some embodiments, the bodies 11, 101, and 201 can be manufactured by an injection molding process. The process cycle for injection molding is very short, typically between 2 seconds and 2 minutes, and consists of the four stages: clamping, injection, cooling and ejection. Injection molding process is performed in an 15 injection molding machine known in the art. An injection molding machine utilize a power source, injection unit, mold assembly, and clamping unit to perform the four stages of the process cycle.
In some exemplary embodiments, for example in the first embodiment, i.e. joint block 10, the injection molding process includes the following steps:
20 Step 1. Preparing a mold, i.e., the mold includes two or more metal or metal alloy parts, that are clamped together to form a cavity with the shape of the joint block 10.
Step 2. Preparing raw material, i.e. nylon 6 granules are mixed with glass fibres (this mixture is referred to hereinafter as, PA6GF). The glass fibres in the mixture 25 range from 30% to 50% by weight, and more preferably are 40% by weight of the mixture.
Step 3: Annealing the raw material, i.e. the raw material PA6GF (30-50) % is annealed at 150-200⁰C in a hot chamber for 1-2 hours to remove moisture for avoiding shrinkage during molding process.
9

Step 4. The annealed raw material is inserted into an injection molding machine configured with the operating temperature range of 230-330 °C.
Step 5: The raw material is injected into the mold.
Step 6: The mold is cooled to a temperature ranging between 40-60 °C, and the 5 formed joint block 10 is ejected from the mold.
Step 7: The formed joint block 10 is finished for removal of any aberrations.
In the second and third embodiments, i.e. joint blocks 100 and 200, the manufacturing process of the joint blocks 100 and 200 includes a combination of plastic molding process for the bodies 101 and 201 respectively and a 10 manufacturing process for the inserts 110 and 210 respectively.
In some embodiments, where the inserts 110 and 210 are made of a metal or a metal alloy, the inserts 110 and 210 can be manufactured by any subtractive manufacturing process, such as machining, cutting, or drilling, knurling, coating or by any additive manufacturing process, such as, 3D printing or selective laser 15 sintering (SLS). In some other embodiments, where the inserts 110 and 210 are made of carbon fibre, the inserts 110 and 210 can be made by any known carbon fibre fabrication process.
The injection molding process for the bodies 101 and 201 of the second and third embodiment of the joint blocks 100 and 200 is similar to the first embodiment of 20 the joint block 10, with an additional step of placing the inserts 110 and 210 inside the mold respectively, while preparing the mold and before the clamping of the mold. This placement of the inserts 110 and 210 while molding the bodies 101 and 201 respectively binds the insert 110 to the body 101, and insert 210 to the body 201 respectively.
25 The following section describes an exemplary use case of the joint block disclosed herein:
Figure 5 is a schematic illustrating the second embodiment of the joint block 100 in a TXV assembly 1000. As shown, the TXV assembly 1000 includes a TXV
10

1001, a gas suction pipe 1002, a bolt 1004, a liquid pipe 1006, and the joint block 100. During assembling of the TXV assembly 1000, the joint block 100 can be attached to the gas suction pipe 1002, by inserting the gas suction pipe 1002 through the aperture 102. The joint block 100 can be free to rotate about the gas 5 suction pipe 1002 at this stage. The joint block 100 can then be rotated about the gas suction pipe to slide the liquid pipe 1006 into the aperture 106 through the side opening 108. The alignment of the joint block 100 between the gas suction pipe 1002 and the liquid pipe 1006, positions the aperture 104 of the insert 110 over an aperture in the TXV 1001. The bolt 1004 can then be tightened in the 10 aperture 104 and the aperture in the TXV 1001 to rigidly fix the joint block 100 onto the TXV 1001. The fixation of the joint block 100 provides structural support to the joints of the gas and liquid pipes 1002 and 1006, respectively, to the TXV 1001.
The above paragraph describes a use case of the second embodiment of the joint 15 block, i.e. joint block 100. The exemplary use cases (not shown) for the first and third embodiments of the joint block 10, 200 are similar to the use case of the joint block 100, for example, in case of the third embodiment, i.e. joint block 200, a liquid pipe can be inserted into the aperture 206, and the joint block 200 can be rotated to slide a gas suction pipe in the aperture 202 through the side opening 20 208. A person skilled in the art, can contemplate further use cases of the different embodiments of the joint block 10, 100, 200 disclosed in this specification.
The following sections describe the properties of the joint block disclosed herein, identified by reasonable experimentation:
For conducting the experimentation, an exemplary joint block 100 of the second 25 embodiment with the following specification was used: The body 101 of the exemplary joint block 100 was made of 30-50% glass filled nylon 6 polymer. The insert 110 was made of mild steel. The exemplary joint block 100 had a length of 65 mm, width of 28 mm, and height of 11 mm. The distance between the centres of apertures 102 and 104 was 22 mm, and distance between the centres of 30 apertures 104 and 106 was 18 mm. The radius of aperture 102 was 8.4 mm, the
11

radius of aperture 104 was 3.25 mm, and the radius of aperture 106 was 4.25 mm. The width of the side opening 108 was 8.5 mm. The insert 110 had a height of 11 mm and an outer circumferential radius of 6.5 mm. The depression 112 had a radius of 4.5 mm, a height of 5 mm, and a depth of 2 mm.
Results of the experiments conducted on the exemplary joint block 100 indicate that it can withstand service temperature of 220°C.
Results of the experiments conducted on the exemplary joint block 100 indicate that it can lead to weight reduction in aluminium joint block by more than 30%. Prior art aluminium joint blocks weight about 40 g (Approx.) and the embodiments of the joint block disclosed herein weigh about 25 g (Approx.), leading to a weight reduction of around 35%.
Experimentation results indicate that the exemplary joint block 100 meets vehicular specifications as presented in Table 1 below. Table 1 also draws a comparison of the joint block disclosed herein with prior art, i.e. aluminium joint blocks, and PDC type joint blocks.

Experimental results indicate that the maximum material allowable stress without any insert at fixing point on the exemplary joint block 100 (without the insert 110) due to bolt tightening was 76.5 MPa, and maximum material allowable stress without any insert at pipe insertion point on the exemplary joint block 100 due to pressure was 20 MPa.
Experimental results indicate further indicate that the exemplary joint block 100 with a generic off the shelf insert made of mild steel (MS) had maximum material allowable stress at fixing point on the joint block due to bolt tightening at 43.1 MPa.
Experimental results indicate that when a MS washer was added on top of the exemplary joint block 100 (without the insert 110), the maximum material allowable stress due to bolt tightening was 58.6 MPa.
Experimental results indicate that when a MS washer was added inside the aperture 104 of the exemplary joint block 100 (without the insert 110), the maximum material allowable stress inside the joint block due to bolt tightening was 50.3 MPa.
Experimental results indicate that the maximum material allowable stress on the joint block 100 with the insert 110 due to bolt tightening was 28.3 MPa.
The above experimental stress test results are summarized in Table 2 below:

The usefulness of the joint block disclosed herein was further confirmed by the advantages seen using different testing parameters. Several tests were conducted to test the joint block including Repeated Pressurisation; Thermal Cycle; Vibration Resistance; Airtightness Performance / air tightness test/ leak test/air proofing test; Pressure durability Performance/ Withstand pressure test/ Pressure-proof test/ proof test/ pressure resistance Test; Burst Pressure test; Corrosion Resistance/ Salt spray test; Repeated tightening performance of thread area; Over Tightening performance of thread area; Low Temp Hold Test; High Temp Hold test; Impact resistance performance; Humidity Resistance; Tightening Torques; etc.
Various other modifications, adaptations, and alternative designs are of course possible in light of the above teachings. Therefore, it should be understood at this time that within the scope of the appended claims the invention might be practiced otherwise than as specifically described herein.

ADVANTAGES
The main advantage of the present invention is that it provides a joint for use in a Thermal Expansion Valve (TXV) assembly in an air conditioning system.
Another objective of this invention is to provide a joint that has a reduced weight.
Another objective of this invention is to provide a joint that has a reduced cost of manufacturing.
Another objective of this invention is to provide a joint that has a reduced time of manufacturing.

We Claim:
1. A joint block (10, 100, 200) for use in a thermal expansion valve (TXV)
assembly of an air conditioning system, the joint block comprising:
a body (11, 101, 201) including:
an aperture (12, 102, 202) for fitting a gas suction pipe connected to the TXV assembly;
an aperture (16, 106, 206) for fitting a liquid pipe connected to the TXV assembly; and
an aperture (14, 104, 204) for fitting a bolt for connecting the joint block to the TXV assembly,
wherein the body (11) is made of a glass filled polymer.
2. The joint block (10, 100, 200) as claimed in Claim 1, wherein the glass filled polymer includes nylon 6 with a glass composition ranging between 30% and 50%.
3. The j oint block as claimed in Claim 2, wherein the glass filled polymer includes glass filled nylon 6 with a glass composition of 40%.
4. The joint block (100, 200) as claimed in Claim 1, wherein the joint block (100, 200) includes an insert (110, 210), and wherein the insert (110, 210) includes the aperture (14, 104, 204) for fitting the bolt.
5. The joint block (200) as claimed in Claim 1, wherein the aperture (202) for fitting the gas suction pipe include a side opening (208) to allow the gas suction pipe to slide into the aperture (202).

6. The joint block (10, 100) as claimed in Claim 1, wherein the aperture (16, 106) for fitting the liquid pipe includes a side opening (18, 108) to allow the liquid pipe to slide into the aperture (16, 106).
7. The joint block (100, 200) as claimed in Claim 1, wherein the joint block (100, 200) includes an insert (110, 210), wherein the insert includes:
an aperture (104, 204) across the longitudinal axis for fitting the bolt; and
a depression (112, 212) positioned along an outer circumferential surface of the insert.
8. The joint block (100, 200) as claimed in Claim 7, wherein the outer circumferential surface (111, 211) of the insert (110, 210) includes one or more protrusions or ridges, is knurled, or is roughened.
9. A method of manufacturing the joint block (10, 100, 200) as claimed in Claim 1, wherein the method includes:
injecting glass filled plastic in a mold;
cooling the mold;
ejecting the formed joint block from the mold; and
finishing the joint block (10, 100, 200).

10. A method of manufacturing the joint block (100, 200) as claimed in Claim 9, wherein the method includes a step of placing an insert (110, 210) in the mold before injecting glass filled plastic in the mold.