Patent Grant
7686198
Generally, nail guns have an air chamber for collecting pressurized air from an air source as a power source for nail guns and a cylinder mounted in a housing. The cylinder may be movably relative to the housing or be fixed on the housing. The cylinder includes a piston slidably disposed therein. The piston divides an inner chamber of the cylinder into a top cylinder chamber and a lower cylinder chamber. The nail gun also includes a trigger valve that is capable of being triggered by pressing so as to drive nail hitting action of the nail gun. The pressurized air in the air chamber enters into the top cylinder chamber to press the piston move downwardly when a trigger of the trigger valve is pressed. The pressurized air in the top cylinder chamber vents from the top cylinder chamber and enters into the lower cylinder chamber to drive the piston move upwardly to its original position.
Nail guns employing movable cylinders have been developed, for example, U.S. Pat. No. 4,784,308, U.S. Pat. No. 4,319,705 and U.S. Pat. No. 4,294,391 disclose a nail gun employing a movable main valve and a movable cylinder separated from the main valve. The main valve can move downwardly or upwardly together with the cylinder. Specifically, the pressurized air in the air chamber drives the main valve and the cylinder to move upwardly when the trigger is pressed. As such, the air venting passage of the lower cylinder chamber, and the air flow passage between the main valve and the cylinder are opened. As a result, the pressurized air in the air chamber enters into the top cylinder chamber to move the piston downwardly to hit the nail. The main valve drives the cylinder move downwardly to its original position when the trigger is released. In this instance, the upper air venting passage is opened such that the piston move upwardly back to its original position.
In each of the aforementioned nail guns employing movable main valves and movable cylinders, an air flow passage is employed to conduct pressurized air to drive the main valve and the cylinder to move so as to control the piston moving upwardly back to its original position. In addition, the air flow passage is formed in a number of separate parts, for example, movable cylinder, inner sidewall of the housing and a bushing disposed around the cylinder. The structure of the air flow passage is too complicated. As a result, controlling of nail hitting of the nail gun is unstable. This issue becomes significant especially after the nail gun has been used for a period due to abrasion between different parts. In addition, a cost of manufacturing such an air flow passage is also very high. Therefore, there is a desire to provide a nail gun employing movable main valve and movable cylinder which can achieve a high stability of controlling of nail hitting.
To overcome aforementioned problem, an object of the present invention is to provide a bushing mounted in a nail gun. The air flow passage is integrally formed in the bushing so as to improve a stability of controlling of nail hitting motion and reduce a complexity of the air flow passage.
In one embodiment, a bushing for conducting air in a nail gun is provided. The bushing is arranged between an air chamber and a cylinder received in a housing of the nail gun. The bushing is adjacent to a bottom of a main valve for driving hitting motion of the nail gun. A number of main valve holes that are adjacent to the main valve are formed in a sidewall of the cylinder. At least one air inlet is formed in a bottom of a sidewall of the cylinder. An air flow passage is defined in the housing and is in communication with the main valve and the air hole. A valve plug which is configured for opening or closing the air flow passage is received in the air flow passage. The valve plug divides the air flow passage into an upper portion and a lower portion. The lower portion is formed in the housing.
An annular end surface is formed on a top of the bushing. The annular end surface defines a main air inlet for the main valve. An end portion extends from the bushing and having the upper portion of the air flow passage formed therein. The bushing further includes at least one upper air hole in communication with the air chamber, the main inlet and the upper portion of the air flow passage.
In the present nail gun, the upper portion of the air flow passage is only integrally formed in the bushing, which can facilitate improving a stability of controlling of nail hitting motion. Furthermore, the upper portion of the air flow passage has a more simplified structure; a simple manufacturing process and low cost of the present nail gun can be achieved.
In addition, other embodiments are as follows.
An annular groove is formed in an inner side surface of the bushing. The annular groove is in communication with the upper portion of the air flow passage and the main valve holes. The upper air hole is in communication with the annular groove and the air chamber.
At least one locking member extends from the bushing, and at least a portion of the locking member is structured to be capable of being received and secured in a groove formed in an inner sidewall of the housing.
At least one lug portion extends from the bushing, at least an end of the lug portion is capable of being received in a groove formed in an inner sidewall of the housing, a receiving groove is formed in the lug portion, and a cushion is received in the receiving groove.
In order to fully disclose the present invention, the bushing in the nail gun will be described in detail with reference to Figures as follows.
These and other features and advantages of the various embodiments disclosed herein will be better understood with respect to the following description and drawings, in which like numbers refer to like parts throughout, and in which:
What is disposed on a top of the housing 2 is a top cover 26 (as shown in
A piston 30 is slidably received in the cylinder 3. The piston 30 divides an inner chamber of the cylinder 3 into an upper cylinder chamber 31 and a lower cylinder chamber 32. An upper sealing ring 301 and a lower sealing ring 302 encompass the piston 30. Specifically, the upper sealing ring 301 and the lower sealing ring 302 are received in respective annular grooves formed in outer side surface of the piston 30. A trigger valve 6 is mounted in the air chamber 20 and is adjacent to the handle 24. The trigger valve 6 is configured for driving the piston 30 to move downwardly to hit a nail and move upwardly to reset its position. The upper sealing ring 301 is above the main valve holes 33, and the lower sealing ring 302 is below the main valve holes 33 before the piston hit the nail. As such, the piston 30 isolates the inner chamber of the cylinder 3 from the main valve holes 33. The upper sealing ring 301 and the lower sealing ring 302 are all below the main valve holes 33 (as shown in
The main valve 5 can be integrally formed on or surround the top of the cylinder 3. The main valve 5 is also in the top cover 26. The air flow passage 21 includes a valve chamber 22 (as shown in
The top end of the bushing 1 defines an annular end surface 17 (as shown in
In another embodiment, an annular groove 13 is formed in the inner sidewall of the bushing 1. The annular groove 13 surrounds the outer surface of the cylinder 3 and is in communication with the upper portion 12 of the air flow passage 21 and the main valve holes 33 (as shown in
At least one locking member 15 extends from outer sidewall of the bushing 1 (as shown in
In the present nail gun, the upper portion 12 of the air flow passage 21 is only integrally formed in the bushing 1, which can facilitate improving a stability of nail hitting controlling. Furthermore, the upper portion 12 of the air flow passage 21 has a more simplified structure; a simple manufacturing process and low cost of the present nail gun can be achieved.
In addition, the nail gun can also includes a number of valve chambers 22 and a number of lower portions 23 of the air flow passage 21, and correspondingly, same amount of end portions 11, upper portions 12 of the flow passage 21 can be formed on the bushing 1.
The above description is given by way of example, and not limitation. Given the above disclosure, one skilled in the art could devise variations that are within the scope and spirit of the invention disclosed herein, including configurations ways of the recessed portions and materials and/or designs of the attaching structures. Further, the various features of the embodiments disclosed herein can be used alone, or in varying combinations with each other and are not intended to be limited to the specific combination described herein. Thus, the scope of the claims is not to be limited by the illustrated embodiments.
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| Number | Date | Country | |
|---|---|---|---|
| 20100019015 A1 | Jan 2010 | US |
