Claims:1. A leakage testing fixture for reverse light switch of an automobile, the leakage testing fixture comprising:
a housing configured to hold the switch therein, wherein the switch is configured in the housing such that there is no gap between the housing and the sides of the switch to escape air therebetween,
an upper jig for supporting the housing from top,
a lower jig for supporting the housing from bottom,
a inlet pipe connected to the housing for supplying pressurized air to the housing;
a pneumatic cylinder supplying pressurized air to the housing through the inlet pipe;
a hose connected to the housing at upper portion , and
a container having water therein, the container receiving the hose therein,
wherein upon supplying pressurized air from top and bottom side of the switch one by one, if there is leakage in the switch, the air passes through the switch, and thereafter through the hose to the container to produce bubbles in water indicating leakage in switch.

2. The leakage testing fixture as claimed in claim 1, wherein the switch is configured within the housing in upright position.

3. The leakage testing fixture as claimed in claim 1, wherein plunger of the switch is in compressed position within the housing.
, Description:Field of invention

The present invention relates to leakage testing device for components of the automobiles, and more specifically to the leakage testing fixture for reverse light switch of an automobile.

Background of the invention

The reverse light switch is a mechanical device used to control operation of the vehicle reverse lights and is mounted on transmission. The switch is designed to complete the circuit when reverse gear is selected allowing reverse light operation.

Once vehicle gear lever is put in reverse position, the reverse light switch gets actuated mechanically and in turn gives electric signal to reverse lamp. The reverse lamps are electric lamps mounted on tail lamps of vehicle. Vehicle has a must feature of glowing these lamps as soon as vehicle is ready to be driven in reverse direction.

The reverse light switches are made as follows.

Initially a base assembly is fixed a fixture and then with the help of pneumatic press, both terminals are riveted to the base assembly. Greasing is done after the assembly of the terminals. Further, a steel ball is crimped with a plunger with the help of hydro pneumatic press. The plunger assembly created which includes MS washer, a spring retainer, spring and plunger for which also the hydro pneumatic press is used.

Thereafter, the plunger assembly, a diaphragm and main contact is assembled as a one part manually. Further, final crimping is done where the base assembly, the plunger assembly gets crimped with the help of hydro pneumatic press machine.
Finally, adhesive is applied over the base assembly and crimping area by using dispenser.

Once the assembly of the reverse light switch is complete curing is done in Oven for 1hr at 60°C-65°C.

However, during making and use of the reverse light switch, the diaphragm may get dislocated or cracked. Further, the adhesive may become improper and there might be crack in base assembly and improper riveting of terminals. All these type of failures can lead to having an opening /gap in switch. Due to the gap in the switch, when switch is mounted on transmission, leakage of oil present in transmission can happen. This further causes failure of switch by corroding terminals, and hampering mechanical movement of plunger in switch. And as a result reverse lamp will not glow on putting vehicle in reverse gear.

Conventionally, to check leakage or misalignment within the reverse light switch, a fixture of same thread size of the switch is used and the reverse light switch is mounted over the fixture. Air passes through the top side of switch and if any leakage is there on the diaphragm or if diaphragm is dislocated then the failures of the reverse light switch is detected. However, the method of prior art for checking leakage in the reverse light switch is not full proof as there are chances of leakages from bottom body side of the switch, if less adhesive is applied on body Further, there might be any issue at crimping area of the terminals which can also cause water entry or oil entry within the switch thereby leading to failure of the switch.

Accordingly, there exists need to provide leakage testing fixture for automobiles switches which overcomes abovementioned drawbacks.

Objects of the present invention

An object of the present invention is to provide a leak proof switch, for example, a reverse light switch for a vehicle.

Summary of the invention

Accordingly, the present invention provides a leakage testing fixture for reverse light switch of an automobile. The leakage testing fixture comprises a housing configured to hold the switch therein. The switch is configured in the housing such that there is no gap between the housing and the sides of the switch to escape air therebetween. The fixture further comprises an upper jig for supporting the housing from top, a lower jig for supporting the housing from bottom, a inlet pipe connected to the housing for supplying pressured air to the housing, a pneumatic cylinder for supplying pressurized air to the housing through the inlet pipe, a hose connected to the housing at upper portion, and a container having water therein. The container receives the hose therein. Upon supplying pressurized air from top and bottom side of the switch one by one, if there is leakage in the switch, the air passes through the switch, and thereafter through the hose to the container to produce bubbles in water indicating leakage in switch.

Brief description of the figures

The objectives and features of the present invention will be more clearly understood from the following description of the invention taken in conjunction with the accompanying drawings, wherein,

Figure 1 shows a schematic drawing of a reverse light switch used in automobiles;
Figure 2 shows a leakage testing fixture for automobiles switches, in accordance with the present invention; and
Figure 3 shows a block diagram of the working of the fixture of figure 2.

Detailed description of the present invention:

The foregoing objects of the present invention are accomplished and the problems and shortcomings associated with the prior art, techniques and approaches are overcome by the present invention as described below in the preferred embodiment.

For the better understanding of this invention, reference would now be made to the embodiment illustrated in greater depth in the accompanying figures and description herein below, further, in the following figures, the same reference numerals are used to identify the same components in various views/figures.

Referring now to figure 1, there is shown a reverse light switch (50). The reverse light switch (50) is a mechanical switch used to control operation of the vehicle reverse lights and is mounted on transmission. The switch (50) comprises a plunger (2), body (4) and terminals (6).

Referring now to figure 2, there is shown a leakage testing fixture (100) (hereinafter ‘the fixture (100)’) for reverse light switch (50) of an automobile, in accordance with the present invention. The fixture includes housing (10). The housing (10) is configured to hold the switch (50) therein. In an embodiment, the switch (50) is configured in the housing (10) such that there is no gap between the housing (10) and the sides of the switch (50) to escape air therebetween. In another embodiment, the switch (50) is configured within the housing (10) in upright position.

The fixture (100) further comprises an upper jig (12) for supporting the housing (10) from top and a lower jig (14) for supporting the housing from bottom. The fixture (100) further more comprises an inlet pipe (16) connected to the housing (10) for supplying pressured air to the housing (10). In an embodiment, a pneumatic cylinder (18) is provided for supplying pressurized air to the housing (10) through the inlet pipe (16). A button (not shown) is provided to make the pneumatic cylinder (18) on and off.

The fixture (100) also comprises hose (20) connected to the housing (10) at upper portion. The hose (20) starts from the upper portion of the housing (10) and ends in a container (22) having water therein.

In an embodiment, the plunger (52) of the switch (50) is kept in compressed position within the housing (10) so as to avoid any gap inside the switch (50) to escape air therefrom.

Upon supplying pressurized air from top and bottom side of the switch (50) configured in the housing (10) one by one, if there is leakage in the switch (50) , the air passes through the switch (50), and thereafter through the hose (20) to the container (22) to produce bubbles in water indicating leakage in switch.

Figure 3 shows a block diagram showing working of the fixture (100). The fixture (100) includes a pressure indicator operably connected to the housing (10) to indicate pressure within the housing (10). Further, fixture (100) also includes a time indicator operably connected to the housing (10) to indicate time for which pressured air is forced within the housing (10).

The fixture (100) is an electro pneumatic machine in which air pressure is forced from top and bottom side of the switch (50) one by one. The hose (20) is immersed in container having water therein. Indication of bubbles in water indicates leakage in the switch (50). The fixture (100) is such that no air leakage passes to environment once switch is locked in clamps of the housing (10).

Advantages of the invention

1. The fixture (100) can be used to confirm that there is no leakage in the switch (50) from top side as well as from bottom side.

2. The fixture (100) ensures that there is no diaphragm dislocation, breakages as well as any leakage from body or terminals which confirming 100% detection of parts.

The foregoing objects of the invention are accomplished and the problems and shortcomings associated with prior art techniques and approaches are overcome by the present invention described in the present embodiment. Detailed descriptions of the preferred embodiment are provided herein; however, it is to be understood that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure, or matter. The embodiments of the invention as described above and the methods disclosed herein will suggest further modification and alterations to those skilled in the art. Such further modifications and alterations may be made without departing from the spirit and scope of the invention.