1. Field of the Invention
The present invention relates to a pressure switch, and more particularly to a pressure switch that has a micro-adjust function for preventing the pressure switch from an interior bad contact.
2. Description of Related Art
A conventional pressure switch in accordance with the prior art shown in
The pressure receiver (500) pushes the elastic plate (501) to contact with the electrode (502) for forming a closed circuit when fluid flows into the body (50) through the inlet (510) and the pressure receiver (500) senses a pressure. However, the elastic plate (501) may cause an elastic fatique condition after being used for a period of time. As a result, a bad contact may be caused between the elastic plate (501) and the electrode (502).
The present invention has arisen to mitigate and/or obviate the disadvantages of the conventional pressure switch.
The main objective of the present invention is to provide an improved pressure switch that has a micro-adjust function for preventing the pressure switch from an interior bad contact.
To achieve the objective, the pressure switch in accordance with the present invention comprises a body, a lower cap and an upper cap respectively mounted to two opposite ends of the body. A casing is airtightly sleeved on an outer periphery of each of the lower cap and the upper cap. There are two electrodes disposed in the body and selectively electrically contacted with each other. A micro-adjust set is disposed in the body to adjust a distance between the two electrodes for preventing the pressure switch from an interior bad contact when the pressure switch is used for a period of time.
Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.
Referring to the drawings and initially to
The body (10) has a receiving space (11) defined therein and formed with a close end and an open end. Four passages (12) are respectively and longitudinally defined in a periphery of the receiving space (11), and a threaded hole (13) defined in the close end of the body (10) and communicating with the receiving space (11). A micro-adjust set (110) is received in the receiving space (11). The micro-adjust set (110) includes a cap (115) urged the close end of the body (10) and corresponding to the threaded hole (130). A resilient member (114), an adjust seat (113), a insulate stick (112) and an insulator (111) sequentially disposed on the cap (115), wherein the resilient member (114) is compressively mounted between the cap (115) and the adjust seat (13) and the insulator (111) is sleeved on the insulate stick (112). A first lead (120), a second lead (121), a third lead (122) and a fourth lead (123) are respectively inserted into a corresponding one of the four passages (12). A bolt (130) is screwed through the threaded hole (13) to abut against a bottom of the cap (115).
The lower cap (20) has two passages (22) longitudinally defined therein. A first prong (220) and a second prong (221) respectively extend through a corresponding one of the two passages (22) in the lower cap (20) and are electrically connected to the first lead (120) and the second lead (121). The first prong (220) and the second prong (221) respectively have a clamp (220A, 221A) formed on one end thereof for clamping the first lead (120) and the second lead (121). A first O-ring (21) is mounted around the lower cap (20) for securely abutting against an inner periphery of the casing (30) to achieve an airtight effect.
The upper cap (40) includes an inlet (400) defined therein and extending therethrough. A second O-ring (41) is disposed in an inner periphery of the inlet (400) and a third O-ring (410) is mounted around the upper cap (40) for securely abutting against the inner periphery of the casing (30) to achieve an airtight effect. A free space (401) is defined in the upper cap (40) for sequentially receiving a washer (42), a diaphragm (43), a first seat (44) and a second seat (45). A first resilient film (440) and a second resilient film (450) are respectively disposed in the first seat (44) and the second seat (45). The diaphragm (43) selectively closes the inlet (400). The insulator (111) is movably received in the second seat (45). The insulate stick (111) sequentially extends through second seat (45), the second resilient film (450) and the first seat (44) and abuts against the first resilient film (440).
With reference to
With reference to
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Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.
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