Information
-
Patent Grant
-
6626081
-
Patent Number
6,626,081
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Date Filed
Thursday, January 24, 200222 years ago
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Date Issued
Tuesday, September 30, 200321 years ago
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Inventors
-
Original Assignees
-
Examiners
- Look; Edward K.
- Kershteyn; Igor
Agents
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CPC
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US Classifications
Field of Search
US
- 091 408
- 091 409
- 092 85 R
- 227 130
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International Classifications
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Abstract
An air-seal structure for pneumatic nailers includes a valve member movably engaged with the end cap of the nailer and a plurality of paths defined radially through a skirt portion of the valve member. The paths are in communication with air release passage defined in the end cap. A seal is mounted to the skirt portion of the valve member and closes the paths. The seal contacts an end of the cylinder when the trigger is not squeezed. The seal is sucked due to the difference of pressure so that it will not be loosened during movement of the valve member. A cushion member is connected to a disk member on the inside of the end cap so as to absorb shocks when the piston returns back to the ready position.
Description
FIELD OF THE INVENTION
The present invention relates to a pneumatic nailer wherein a plurality of paths are defined radially through the valve member and a seal between the cylinder and the valve is sucked tightly when the trigger is not squeezed.
BACKGROUND OF THE INVENTION
An air valve for a conventional pneumatic nailer is shown in FIG.
1
and generally includes an end cap
11
connected to a rear end of the body
15
of the nailer and a valve member
12
is movably engaged with an annular space
111
of the end cap
11
. Two seals
125
,
126
are embedded to the inner and the outer periphery of the valve member
12
and are moved along the surfaces of the annular space
111
. A cylinder
16
is received in the body
15
and has a flange
161
which is securely engaged with an inside of the body
15
. A seal
112
is connected to the valve member
12
and contacts an end of the cylinder
16
so as to seal the conjunction portion between the cylinder
16
and the valve member
12
. The end cap
11
has a tubular portion
121
which has a groove for receiving a spring
13
therein which urges the valve member
12
to let the seal
112
contact the cylinder
16
. A piston
18
is movably received in the cylinder
16
and an injection rod
19
is connected to the piston
18
. The piston
18
has a protrusion extending through the valve member
12
and contacting an end surface
122
on the tubular portion
121
. When the user squeeze the trigger of the nailer, the valve member
12
is moved toward the tubular portion
121
and pressurized air enters the cylinder
16
to move the piston
18
to inject a nail. The seals
125
,
126
will be worn out after frequent movement on the surfaces of the annular space
111
. The seal
112
hits on the cylinder
16
when the pressurized air is released from release path of the nailer and the valve member
12
is pushed back by the spring
13
. This could loosen the position of the seal
112
. The piston
18
returns back by the air flow after the nail is injected and the protrusion hits the end surface
122
of the end cap
11
. This will shank the whole assembly and leakage could happens.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention, there is provided a air-seal structure for pneumatic nailers and the structure comprises a valve member that has a skirt portion movably engaged with an annular space of the end cap and first seals are connected to the skirt portion of the valve member. A spring is biased between the skirt portion and an inside of the annular space. A plurality of paths are defined radially through the valve member and communicate with air release passage defined in the end cap. A second seal is connected to the valve member and closes the paths. The second seal removably contacts an rear end of a cylinder in the mailer body. A cushion member is engaged with a disk member connected to an inside of the end cap and has an recess defined in a side thereof. A piston is movably received in the cylinder and an injection rod is connected to the piston. The piston has a protrusion which is disengagably engaged with the recess.
The primary object of the present invention is to provide an air-seal structure for pneumatic nailers and the structure occupies less space and effectively enhances the air-seal feature of the nailer.
The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a cross sectional view to show the air-seal structure of a conventional pneumatic nailer;
FIG. 2
is an exploded view to show the parts of the air-seal structure of a pneumatic nailer of the present invention;
FIG. 3
is a cross sectional view to the air-seal structure of the pneumatic nailer of the present invention, wherein the piston is moved away from the cushion member, and
FIG. 4
is a cross sectional view to the air-seal structure of the pneumatic nailer of the present invention, wherein the piston is moved back to the cushion member.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to
FIGS. 2 and 3
, the air-seal structure of a pneumatic nailer of the present invention comprises an end cap
50
connected to a rear end of a nailer body
60
and an annular space
500
is defined in the end cap
50
. A tubular valve member
30
has a skirt portion movably engaged with the annular space
500
and two first seals
33
are received in grooves
34
defined in the skirt portion of the valve member
30
so as to be moved along the two facing inner surfaces of the annular space
500
. A spring
43
is biased between the skirt portion and an inside of the annular space
500
. A cylinder
53
is received in the nailer body
60
and the spring
43
urges the valve member
30
to contact an end of the cylinder
53
. A plurality of paths
36
are defined radially through the valve member
30
and communicate with air release passage
51
defined in the end cap
50
. A ring
45
is connected between the end cap
50
and the cylinder
53
.
A groove
35
is defined in an end of the valve member
30
so as to receive a second seal
44
therein and the second seal
44
closes the paths
36
. The second seal
44
removably contacts an rear end of the cylinder
53
to prevent air from entering the cylinder
53
as shown in FIG.
4
.
A disk member
20
is connected to a center portion of an inside of the end cap
50
. The disk member
20
has a plurality of bosses
23
extending from a first side thereof and an engaging recess
22
is defined in a second side of the disk member
20
. A cushion member
40
is engaged with the engaging recess
22
of the disk member
20
and a recess
41
is defined in a side of the cushion member
40
. A screw extends through a hole
41
in the cushion member
40
and the hole
21
in the disk member
20
and is securely engaged with the end cap
50
.
A piston
52
is movably received in the cylinder
53
and an injection rod is connected to the piston
52
. The piston
52
has a protrusion which is disengagably engaged with the recess
41
of the cushion member
40
.
When the trigger is not squeezed, the pressure difference on the two sides of the second seal
44
makes the second seal
44
to be sucked firmly in the groove
35
. This feature allows the manufacturers use smaller parts to design the second seal
44
. When the trigger of the nailer is squeezed, the pressure enters in the cylinder
53
to move the piston
52
away from the cushion member
40
and after a nail is injected, the air is guided to move the piston
52
back to its ready position as shown in FIG.
4
. When the piston
52
returns back, it hits the cushion member
40
and the protrusion is engaged with the recess
41
. A plurality grooves
42
are defined in an edge of the cushion member
40
so that when the protrusion enters the recess
41
, air in the recess
41
escapes from the grooves
42
. The shocks that the piston
52
returns to its ready position are absorbed by the cushion member
40
so that the seals
33
,
44
will not be loosened by the shocks and vibration.
While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.
Claims
- 1. An air-seal structure for pneumatic nailers, comprising:an end cap connected to a rear end of a nailer body and an annular space defined in said end cap, a cylinder received in said nailer body and disk member connected to a center portion of an inside of said end cap; a valve member having a skirt portion movably engaged with said annular space and first seals connected to said skirt portion of said valve member, a spring biased between said skirt portion and an inside of said annular space, a plurality of paths defined radially through said valve member and communicating with air release passage defined in said end cap, a second seal connected to said valve member and closing said paths, said second seal removably contacting rear end of said cylinder; a cushion member engaged with said disk member and having recess defined in a side thereof, and a piston movably received in said cylinder and an injection rod connected to said piston, said piston having a protrusion which is disengagably engaged with said recess.
- 2. The air-seal structure for pneumatic nailers as claimed in claim 1 further comprising a ring connected between said end cap and said cylinder.
- 3. The air-seal structure for pneumatic nailers as claimed in claim 1 further comprising grooves defined in an edge of said cushion member.
US Referenced Citations (4)