Cylinder dividing mechanism of a pneumatic tool

In a cylinder dividing mechanism of a pneumatic tool, the first and second air pressure driving spaces are formed in the chamber, the first and second external channels are set externally on the circumferential wall, the first external channel is connected with the first air intake and air intake/exhaust dividing controller, and the second external channel is connected with the second air intake and air intake/exhaust dividing controller. As such, a single chamber is provided with two air pressure driving spaces for synchronous compression and driving of the rotor. The driving torsion for the pneumatic tool could be multiplied without need of increasing the volume of the chamber of the cylinder to cater for the need of the users with improved applicability.

CROSS-REFERENCE TO RELATED U.S. APPLICATIONS

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NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT

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REFERENCE TO AN APPENDIX SUBMITTED ON COMPACT DISC

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BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a pneumatic tool, and more particularly to an innovative one which is designed with a cylinder dividing mechanism.

The drive system of a pneumatic tool is structurally designed in a way that air pressure is guided into a cylinder to drive the rotation of a vane rotor synchronously with a shaft lever for generating preset actions (e.g.: loosening or locking the bolts).

Generally, a common bias vane is assembled into the cylinder, then a lateral space with larger spacing between the vane and cylinder is taken as a driving space for guiding, compression, expansion and relief of air pressure. Yet, after air pressure is guided into the driving space, a relief port must be set at almost half of the stroke for smooth, continuous rotation of the vane, but the compression stroke of air pressure will be limited, making it difficult to further increase the torsion. Given the fact that the driving torsion of the pneumatic tool depends on the driving force for the vane, it is understood that, if the volume of the cylinder is not increased, the efficient stroke of the vane under air pressure is restricted by the position of the relief port, making it impossible to further increase the stroke and driving torsion (incl.: clockwise and counterclockwise rotation) of the pneumatic tool as a bottleneck in this industry.

Thus, to overcome the aforementioned problems of the prior art, it would be an advancement if the art to provide an improved structure that can significantly improve the efficacy.

Therefore, the inventor has provided the present invention of practicability after deliberate design and evaluation based on years of experience in the production, development and design of related products.

BRIEF SUMMARY OF THE INVENTION

Based on the present invention, the first and second air pressure driving spaces are formed in the chamber, the first and second external channels are set externally on the circumferential wall, the first external channel is connected with the first air intake and air intake/exhaust dividing controller, and the second external channel is connected with the second air intake and air intake/exhaust dividing controller, so a single chamber is provided with two air pressure driving spaces for synchronous compression and driving of the rotor. In such a case, the driving torsion for the pneumatic tool could be multiplied without need of increasing the volume of the chamber of the cylinder to cater for the need of the users with improved applicability.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1-4depict preferred embodiments of a cylinder dividing mechanism of pneumatic tool of the present invention, which, however, are provided for only explanatory objective for patent claims. Said cylinder10is accommodated in the groove21of a pneumatic tool20(a pneumatic spanner). Said cylinder10comprises of a circumferential wall11and an internal chamber12, of which the chamber12is used to hold a rotor30, onto which several vanes31are set circumferentially for abutting onto the circumferential wall11of the cylinder10, thus driving the rotation of the rotor30when air pressure is guided.

The core aspect of the present invention comprises the rotor30set at a central demarcation point in the chamber12, such that the chamber12is segregated into a first air pressure driving space41and a second air pressure driving space42(shown inFIG. 5).

Of which, the first and second air pressure driving spaces41,42have an air intake section b1(B1), a compression section b2(B2) and a pressure relief section b3(B3) (shown inFIG. 5).

An air intake/exhaust dividing controller50is set externally on the circumferential wall11of the cylinder10correspondingly to the joint of the first and second air pressure driving spaces41,42, so as to switch the operating mode of the pneumatic tool20for clockwise or counterclockwise rotation of the rotor30.

A first external channel61and a second external channel62are set externally at interval on the circumferential wall11of the cylinder10, and either end of the first/second external channels61,62is connected with the air intake/exhaust dividing controller50.

A first air intake71is set on the circumferential wall11of the cylinder10and connected with the air intake section b1of the first air pressure driving space41and the air intake/exhaust dividing controller50.

A first air vent81is set on the circumferential wall11of the cylinder10and connected with the pressure relief section b3of the first air pressure driving space41and the first external channel61.

A second air intake72is set on the circumferential wall11of the cylinder10and connected with the air intake section B1of the second air pressure driving space42and the second external channel62.

A second air vent82is set on the circumferential wall11of the cylinder10and connected with the pressure relief section B3of the second air pressure driving space42and the air intake/exhaust dividing controller50.

Referring toFIG. 2, the air intake/exhaust dividing controller50comprises of a valve pipe51and a flow path switching valve52set rotatably in the valve pipe51. The flow path switching valve52includes an air intake duct521, an air intake guiding portion522, an air exhaust guiding portion523and a rotary control button524. A vertical exhaust channel22(marked inFIGS. 2,3) set in the pneumatic tool20can be connected vertically with the air exhaust guiding portion523, such that the first air intake71and one end of the second external channel62on the circumferential wall11are connected with the air intake guiding portion522, and one end of the first external channel61and the second air vent82connected with the air exhaust guiding portion523. Of which, the sectional area of the second external channel62is smaller than that of the first external channel61. When the rotor30is under clockwise rotation mode (marked inFIGS. 5,6), the air pressure thrust of the second air pressure driving space42is smaller than that of the first air pressure driving space41, so as to prevent excessive driving pressure in this mode.

Based upon above-specified structure, the present invention is operated as follows:

Referring toFIG. 5(in collaboration withFIG. 4), when the pneumatic tool20is under an operating mode for driving clockwise the rotor30, the clockwise stream W1in the first flow path guided by the air intake/exhaust dividing controller50is guided through the first air intake71to the first air pressure driving space41from an air intake duct521of the flow path switching valve52, such that the rotor30is driven. Next, the stream W1is discharged from the first air vent81to the first external channel61, then guided from the first external channel61to the air exhaust guiding portion523(shown inFIG. 2) of the flow path switching valve52, and finally discharged from the exhaust channel22.

Referring toFIG. 6(in collaboration withFIG. 4), the clockwise stream W2in the second flow path guided by the air intake/exhaust dividing controller50is guided from the second external channel62to the second air intake72, and then into the second air pressure driving space42for driving the rotor30. Since the sectional area of the second external channel62is smaller than that of the first external channel61, the thrust of stream W2for the rotor30is smaller. Next, the stream W2is guided from the second air vent82to the air exhaust guiding portion523of the flow path switching valve52, and finally discharged from the exhaust channel22(shown inFIG. 2).

Referring also toFIG. 8(in collaboration withFIG. 7), when the pneumatic tool20is under an operating mode for driving counterclockwise the rotor30, the counterclockwise stream W3in the first flow path guided by the air intake/exhaust dividing controller50is guided through the first air vent81to the first air pressure driving space41from the first external channel61, such that the rotor30is driven counterclockwise. Next, W3is guided from the first air intake71to the air exhaust guiding portion523(shown inFIG. 2) of the flow path switching valve52, and finally discharged from the exhaust channel22.

Referring also toFIG. 9(in collaboration withFIG. 7), the counterclockwise stream W4in the second flow path guided by the air intake/exhaust dividing controller50is guided from the second air vent82to the second air pressure driving space42for driving the rotor30for counterclockwise rotation, then from the second air intake72to the second external channel62and furthermore to the air exhaust guiding portion523of the flow path switching valve52, and finally discharged from the exhaust channel22(shown inFIG. 2). With such a design, a single chamber is provided with two air pressure driving spaces for synchronous compression and driving of the rotor30, so the driving torsion for the rotor30and the pneumatic tool could be multiplied without need of increasing the volume of the chamber12of the cylinder10.

Referring toFIG. 3, the first and second external channels61,62are formed by circumferential troughs set at interval externally on the circumferential wall11of the cylinder10. In addition, the first and second external channels61,62are also formed by circumferential troughs set at interval on the groove21of the pneumatic tool20as a preferred embodiment.

Referring also toFIGS. 10 and 11, one end of the second external channel62is directly connected with the exhaust channel22of the pneumatic tool20(not through the flow path switching valve52). With this design, when the rotor30is under clockwise rotation mode, air pressure thrust is guided only by the first air pressure driving space41. When the rotor is under counterclockwise rotation mode, air pressure thrust is guided synchronously by the first and second air pressure driving spaces41,42for compression and driving of the rotor30as a preferred embodiment.