Patent ID: 9562821
Date: 2017-02-07
CPC Classifications: F04B,G01L

Claim:
1. A pressure indicator for an air compressor, comprising: a tube has a first segment and a second segment, the second segment being adapted for connection to one outlet of an air storage container of the air compressor and defining therein a second bore, the first segment being formed integrally with the second segment and having an open end opposite to the second segment and defining therein a first bore that communicates with the second bore, the first bore having a diameter greater than the second bore, a tapered annular surface formed between an inner surface of the first segment, which defines the first bore, and an inner surface of the second segment, which defines the second bore, the first segment defining at its surrounding wall an elongated opening extending from the tapered annular surface to its open end; a stationary transparent plate provided with a marking line and detachably fixed onto the tube; a slider including a hollow cylindrical body having a closed end and an open end and defining therein an inner space that opens out at the open end, the cylindrical body being provided with a central tube that extends from an inner surface of its closed end , through its inner space, to go beyond the open end, the slider further including a panel that is joined to the hollow cylindrical body through a neck portion that is near the open end of the hollow cylindrical body, such that the panel is parallel to the tube, the hollow cylindrical body being fitted into the tube and the neck portion being inserted through the elongated opening, so that the panel is capable of moving together with the hollow cylindrical body, the panel being provided with a layer of pressure-indicating scale at its outer surface; a coiled compression spring fitted into the inner space of the slider, around the central tube of the slider; and a cap has an inner base and a central tube extending from the inner base, the central tube of the cap defining therein a central hole, the diameter of the central hole of the central tube of the cap being greater than the external diameter of the central tube of the slider, the external diameter of the central tube of the cap being less than the internal diameter of the coiled compression spring, whereby the compressed air stored in the air storage container can flow into the second bore of the second segment of the tube via the outlet and thus force the slider to move along the second bore and the first bore towards the open end of the first segment of the tube, so that the position of the marking line of the stationary transparent plate relative to the pressure-indicating scale on the panel of the slider can reveal the pressure of the compressed air within the air storage container, and furthermore, when the compressed air exceeds a predetermined pressure set at the air compressor, the compressed air can be released into the ambient environment through the elongated opening.