AIR INLET FOR PNEUMATIC POWER TOOL

INTRODUCTION

[0001] The present invention generally relates to pneumatic power tools and more particularly to a pneumatic power tool having a gasket assembly that sealingly engages mating portions of the pneumatic power tool and filters air that flows there through.

[0002] Many hand-held pneumatic power tools are provided with a screen in the air inlet port of the tool that is employed to coarsely filter the incoming air flow to prevent relatively large contaminants from entering the trigger or motor of the tool. The relatively small diameter of the air inlet port requires that the filter be correspondingly small and consequently the screen typically has a small surface area that can restrict air flow and thus degrade tool performance.

SUMMARY

[0003] In one form, the present teachings provide a pneumatic power tool with a housing assembly, a pneumatic motor assembly, an output member, and a trigger assembly. The housing assembly has a body, a cap member and a gasket assembly. The body defines a motor cavity and an inlet manifold. The cap member defines an air inlet port. The gasket has a first portion being a band formed of a compressible material and a second portion being a porous material coupled to an interior region of the band. The band of the first portion is sealingly

abutted against the body and cap member. The pneumatic motor assembly is received in the motor cavity defined by the body. The output member is driven by the pneumatic motor assembly. The trigger assembly is coupled to the housing assembly and is operable for selectively operating the pneumatic motor assembly. Pressurized air received into the air inlet port is filtered by the second portion of the gasket assembly and flows into the inlet manifold when the pneumatic motor assembly is operated.

[0004] In another form, the present teachings provide a method that includes: providing a pneumatic power tool having a housing assembly, a pneumatic motor assembly housed by the housing assembly and a trigger assembly that is coupled to the housing assembly and operable for selectively operating the pneumatic motor assembly, the housing assembly including a body and a cap member, the body defining an inlet manifold, the cap member defining an air inlet port; positioning a gasket assembly between the cap member and the body, the gasket member including a seal portion and a porous portion that is coupled to the seal portion and disposed inwardly thereof; and securing the cap member and the gasket assembly to the body such that the seal portion sealingly engages the cap member and the body and the porous portion is disposed between the inlet port and the inlet manifold.

[0005] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and

specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. [0007] Figure 1 is a perspective view of the right side of a tool constructed in accordance with the teachings of the present invention; [0008] Figure 2 is an exploded partial perspective view of a portion of the tool of Figure 1 illustrating the body, gasket assembly and cap member in more detail;

[0009] Figure 3 is a cross-sectional side view of the portion of the tool depicted in Figure 2 illustrating the body, gasket assembly and cap member in even greater detail;

[0010] Figure 4 is a front view of a gasket assembly constructed in accordance with the teachings of the present invention; and [0011] Figure 5 is a partially broken-away perspective view of a portion of another pneumatic tool constructed in accordance with the teachings of the present disclosure.

DETAILED DESCRIPTION OF THE VARIOUS EMBODIMENTS [0012] With reference to Figures 1 through 3 of the drawings, a pneumatic tool constructed in accordance with the teachings of the present disclosure is generally indicated by reference numeral 10. The pneumatic tool 10 can include a housing assembly 12, a pneumatic motor assembly 14, an output member 16 such as a driver 18, and a trigger assembly 20. In the particular embodiment illustrated, the pneumatic tool 10 is a nailer, but it will be appreciated that the teachings of the present disclosure have applicability to other types of hand-held pneumatic tools, including those having a rotary, axial, reciprocating, oscillating and/or orbital output.

[0013] The housing assembly 12 can include a housing 26, a cap member

28 and a gasket assembly 30. With additional reference to Figures 2 and 3, the housing 26 can include a body 40 and a handle 42 that can be configured to permit an operator to manipulate and guide the pneumatic tool 10 in a desired manner. In the particular example illustrated, the body 40 can define a motor cavity 44, which can be configured to at least partially house the pneumatic motor assembly 14, while the handle 42 can define an inlet manifold 46 that can serve as a reservoir of compressed air that can be coupled in fluid connection to the motor assembly 14 and the trigger assembly 20. The proximal end of the handle 42 can be coupled to the body 40, while the distal end of the handle 42 can define a first sealing surface 48.

[0014] The cap member 28 can be removably coupled to the handle 42 in any appropriate manner, such as threaded fasteners 52, to close the open end of the inlet manifold 46. The cap 38 can define an air inlet port 60 and a second sealing surface 68. The air inlet port 60 can include a threaded connection 62, such as a female threaded connection, that can be employed to couple the pneumatic tool 10 to a source of compressed air (not shown). [0015] With reference to Figure 4, the gasket assembly 30 can include a seal member 70 and a filter member 76 that can be sealingly coupled to the seal member 70 by any appropriate means, such as overmolding (i.e., overmolding the seal member 70 onto the filter member 76) or bonding. The seal member 70 can be formed of an appropriate material that is configured to sealingly engage the first and second sealing surfaces 48 and 68. The seal member 70 can be a band-shaped structure that defines an interior region 82.

[0016] The filter member 76 can be sealingly coupled to the seal member

70 and can extend across the entirety of the interior region 82. The filter member 76 can be formed of an appropriate material for filtering compressed air input to the pneumatic tool. A relatively coarse filter member 76 may be desirable in some situations and as such, the filtering material can be a screen or mesh that can be formed of metal, plastic or textile, for example. A relatively fine filter member 76 may be desirable in other situations and as such, the filter material can be a porous paper, ceramic, foam or plastic filter media element. It will be appreciated that combinations of materials may be employed to form the filter

member 76. For example, the filter member 76 could be formed of discrete layers of progressively finer filter material.

[0017] The filter member 76 can be formed of a mesh of a suitable material (e.g., stainless steel, bronze, brass) and can have a desired mesh size, such as 30 mesh or higher. Alternately, the filter member 76 can be formed of a porous material, such as a filter paper, an open-cell foam, a ceramic or a sintered material, and can have a porosity that is suited to provide a desired degree of filtering while permitting an air flow of a desired mass-flow rate to flow there through.

[0018] In the particular example provided, the filter member 76 is formed of a wire mesh having an open area of about 30% and the seal member 70 is formed of a thermoplastic elastomer that is overmolded onto the filter member 76 and encapsulates and/or sealingly engages an outer portion of the filter member 76. In the configuration illustrated, the area of the filter member 76 through which air may flow is about 1.693 square inches, whereas the cross-sectional area of the housing assembly 12 where the gasket assembly 30 is located is about 2.345 square inches. As such, the ratio of the area of the flowable filter media to the cross-sectional area of the housing assembly 12 where the gasket assembly 30 is located is about 0.72.

[0019] Returning to Figure 3, the pneumatic motor assembly 14, the output member 16 and the trigger assembly 20 are at least partially contained in the housing assembly 12. As those of ordinary skill in the art will appreciate, the

pneumatic motor assembly 14, the. output member 16 and the trigger assembly 20 can be constructed in any appropriate manner. For example, the pneumatic motor assembly 14, the output member 16 and the trigger assembly 20 can be constructed in the manner described in commonly assigned U.S. Patent No. 6,648,202 entitled "Pneumatic Fastening Tool" issued on November 18, 2003, the description of which is hereby incorporated by reference as if fully set forth in detail herein.

[0020] In the particular example provided, the pneumatic motor assembly

14 includes a pneumatic cylinder 102 and a piston 104 that is fixed to the output member 16. The piston 104 can be movable between a retracted position and an extended position. The trigger assembly 20 can be coupled in fluid connection to the air inlet manifold 46 and can be employed to control the application of fluid pressure to the piston 104 to cause the piston 104 to move between the retracted and extended positions. When the trigger assembly 20 is selectively engaged by an operator to activate the pneumatic tool 10, pressurized fluid is applied to the piston 104 to thereby propel the piston 104 in a linear direction along the axis of the pneumatic cylinder 102 to the extended position. As the piston 104 is fixed to the output member 16, translation of the piston 104 to the extended position permits the output member 16 to drive a fastener (not shown), such as a nail or staple, into a workpiece.

[0021] While the pneumatic tool 10 has been illustrated and described herein as including a gasket assembly 30 with a filter member 76 that is formed

of a material with substantially planar opposite surfaces, those of skill in the art will appreciate that the invention, in its broadest aspects, may be constructed somewhat differently. For example, a pneumatic tool 10a having a gasket assembly 30a is shown in Figure 5. In this example, the gasket assembly 30a can include the seal member 70 and a filter member 76a having a flange portion 150 and a three-dimensionally contoured body portion 152 to provide the gasket assembly 30a with an effective filtering area (i.e., the surface area of the filter member 76) that is greater than an interior area of the pneumatic tool 10a at a location where the seal member 70 contacts a sealing surface (e.g., the first sealing surface 48 (Fig. 3). Preferably the effective filtering area is at least 25% greater than the interior area. More preferably, the effective filtering area is at least 40% greater than the interior area and still more preferably, the effective area is at least 80% greater than the interior area. The filter member 76 of the gasket assembly 30a has a longitudinal cross-section that is at least partially defined by a parabola in the particular example provided. Those of skill in the art will appreciate from this disclosure that the particular three-dimensional shape employed may include other desired shapes, including shapes that are at least partially conical and/or frustoconical. The pneumatic tool 10a can be otherwise similar to the pneumatic tool 10 (Fig. 1).

[0022] Aside from the three-dimensional contoured shape of the body portion 152, the gasket assembly 30a can be generally similar to the gasket assembly 30 (Fig. 4). In this regard, the filter member 76a can be sealingly

coupled to the seal member 70 by any appropriate means, such as overmolding (e.g., overmolding the seal member 70 onto the filter member 76a) or bonding. Furthermore, the filter member 76a can be formed of any appropriate filter media or combination of filter media. Those of skill in the art will appreciate that the contoured body portion 152 can have a large filter surface area (relative to a surface area of the gasket assembly 30 (Fig. 4)) so as to provide increased air flow capacity and/or increased life expectancy of the filter. In the particular example provided, the area of the filter member 76a through which air may flow is about 4.700 square inches, whereas the cross-sectional area of the housing assembly 12 where the gasket assembly 30a is located is about 2.345 square inches. As such, the ratio of the area of the flowable filter media to the cross- sectional area of the housing assembly 12 where the gasket assembly 30a is located is about 2.00.

[0023] In the particular example provided, the flange portion 150 and the contoured body portion 152 are unitarily formed from a plastic material such that the flange portion 150 is non-porous while the contoured body portion 152 is porous. Those of ordinary skill will appreciate that one or more layers (not shown) of a filtering material may be layered onto contoured body portion 152 to progressively filter the air that is passed therethrough.

[0024] While specific examples have been described in the specification and illustrated in the drawings, it will be understood by those of ordinary skill in the art that various changes may be made and equivalents may be substituted for

elements thereof without departing from the scope of the present disclosure as defined in the claims. Furthermore, the mixing and matching of features, elements and/or functions between various examples is expressly contemplated herein so that one of ordinary skill in the art would appreciate from this disclosure that features, elements and/or functions of one example may be incorporated into another example as appropriate, unless described otherwise, above. Moreover, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the essential scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular examples illustrated by the drawings and described in the specification as the best mode presently contemplated for carrying out this invention, but that the scope of the present disclosure will include any embodiments falling within the foregoing description and the appended claims.