This invention relates to the field of devices used to drive fasteners into work-pieces and particularly to a work contact element for use with such devices.
Fasteners such as nails and staples are commonly used in projects ranging from crafts to building construction. While manually driving such fasteners into a work piece is effective, a user may quickly become fatigued when involved in projects requiring a large number of fasteners and/or large fasteners to be driven into a work piece. Moreover, proper driving of larger fasteners into a work piece frequently requires more than a single impact from a manual tool.
In response to the shortcomings of manual driving tools, power-assisted devices for driving fasteners into work pieces have been developed. Contractors and homeowners commonly use such devices for driving fasteners ranging from brad nails used in small projects to common nails which are used in framing and other construction projects. Compressed air has been traditionally used to provide power for the power-assisted (pneumatic) devices.
Various safety features have been incorporated into pneumatic and other power nailers. One such device is commonly referred to as a work contact element (WCE). A WCE is incorporated into nailer designs to prevent unintentional firing of the nailer. A WCE is typically a spring loaded mechanism which extends forwardly of the portion of the nailer from which a nail is driven. In operation, the leading side surface, or contact surface of the WCE is pressed against a work piece into which a nail is to be driven. As the WCE is pressed against the work piece, the WCE compresses the spring and generates an axial movement which is transmitted to a trigger assembly. The axial movement is used to reconfigure a safety device, also referred to as a trigger enabling/disabling mechanism, so as to enable initiation of a firing sequence with the trigger of the nailer.
Nailers may be used for many different jobs. One particular type of job where nailers have found widespread use is in the installation of roofing materials, such as asphalt shingles. Asphalt shingles are a very abrasive material due to the granules of stone that are on the surface of the shingles. Repeated contact between the contact surface of the work contact element and the shingles may cause wear to the contact surface. Due to the potential for wear during roofing applications, some previously known nailers have incorporated wear resistant inserts into the contact surface of the work contact element. The previously known inserts were typically round inserts positioned on opposing sides of the ejection orifice in the work contact element and protruding from the contact surface to contact the abrasive surface of the shingles so as to limit contact between the contact surface and the shingles.
Other surfaces of the WCE may also be susceptible to wear during the installation of shingles. For example, the fastener driving tool may be provided with a shingle gauge assembly to aid in the uniform spacing of shingles. The shingle gauge includes an alignment surface that is substantially parallel to an upper trailing side of the WCE that may be used to control the distance that a fastener is placed into a shingle from the edge of the shingle. During use, the alignment edge of the shingle gauge is lined up with a previously installed shingle. The upper trailing side surface of the WCE may then be used to line up the next row of shingles. This action causes the trailing side surface of the WCE to be pressed and rubbed against the narrow edge of shingles which may result in wear on the trailing side front surface of the work contact element.
One method that may be used to prevent or limit wear to the trailing side surface of the WCE is to add additional inserts that protrude from the trailing side surface to contact the narrow edge of shingles during the alignment process discussed above with regard to the shingle gauge. However, adding additional inserts to the WCE may increase the complexity and cost of manufacturing of the work contact element and have a negative impact on the structural integrity of the WCE.
In accordance with one embodiment, there is provided a fastener driving tool that includes a housing, a nose assembly having a fastener passage configured to allow fasteners to be advanced therethrough, and a safety contact assembly movable in relation to the nose assembly between a disable position and an enable position. A magazine assembly is configured to supply fasteners toward the nose assembly, and a driver is configured to cause a fastener located in the fastener passage to be advanced within the nose assembly. The nose assembly includes (i) a base member defining at least a portion of the fastener passage and has a first recess and a second recess which are spaced apart from each other, (ii) a first protection insert located in the first recess, and (iii) a second protection insert located in the second recess. The base member defines a leading side surface and a trailing side surface. The leading side surface defines an ejection orifice that is aligned with the fastener passage. The leading side surface defines a first opening aligned with the first recess and a second opening aligned with the second recess, and the trailing side surface defines a third opening aligned with the first recess and a fourth opening aligned with the second recess. The first protection insert extends through the first opening and the third opening, and the second protection insert extends through the second opening and the fourth opening.
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and described in the following written specification. It is understood that no limitation to the scope of the invention is thereby intended. It is further understood that the present invention includes any alterations and modifications to the illustrated embodiments and includes further applications of the principles of the invention as would normally occur to one skilled in the art to which this invention pertains.
The fastener driver 32 is configured to be moved into and out of the fastener passage 24 along an axis A that is aligned with the fastener passage 24. Any suitable device or method may be used to cause the fastener driver 32 to drive fasteners into and out of the fastener passage. In one embodiment, the fastener driving tool 10 is configured to use a pneumatic driving force to actuate the fastener driver. In this embodiment, the handle portion 14 of the housing may include a reservoir (not shown) therein for pressurized air supplied by a conventional pressurized air source (not shown). The receptacle area 18 may be used to connect a source of compressed air or other source of power to the reservoir in the handle portion of the fastener driving tool. The drive section 20 of the housing may include a cylinder (not shown) with a reciprocating piston (not shown) operably coupled to the driver blade such that when the trigger is actuated, air forces the piston downward, causing driver blade 32 to force a fastener 28 located in the fastener passage 24 out the end of the fastener passage.
The fastener driving mechanism described herein is exemplary only and is not intended to be limiting. It is understood that a fastener driving mechanism of any conventional construction may be used and is not limited to the representative embodiment disclosed in the present application. For example, in alternative embodiments, the fastener driving mechanism of the fastener driver may be actuated by a fly wheel assembly or a solenoid assembly in electrically actuated tools. The driver may also be actuated by internal combustion.
The fastener driving tool 10 includes a contact safety assembly 36 configured to prevent actuation of the driver mechanism when the nose assembly 22 is not in contact with a workpiece (not shown). As best seen in
The work contact element 40 is operably coupled to the trigger enabling portion 38 such that movement of the work contact element 40 between the retracted and extended positions mechanically repositions the trigger enabling portion 38. When the work contact element 40 is moved to the retracted position, the trigger enabling portion 38 is configured to place the trigger 16 in an active state or condition so that manual movement of the trigger 16 thereafter through its actuation stroke is capable of actuating the fastener driving mechanism. When the work contact element 40 is in the extended position, the trigger enabling portion 38 places the trigger 16 in an inactive state or condition to prevent the fastener driving tool 10 from being accidentally actuated if the trigger mechanism 16 is moved through its actuation stroke. The trigger enabling portion 38 of the contact safety assembly 36 may be implemented in any suitable manner.
Referring now to
The exemplary fastener driving tool 10 depicted in
Referring now to
With reference to
The base member 54 also includes an upper trailing side surface 64 (referred to hereafter as “trailing side surface”), and a pair of lateral side surfaces 66, 68. The trailing side surface 64 and the contact surface 60 meet to define an alignment edge 66. The trailing side surface 64, the lateral side surfaces 66, 68, and the contact surface meet to define leading edge or alignment edge corners 70, 72. The trailing side surface 64 of the base member 54 is a substantially flat surface arranged generally perpendicular to the leading side surface 60. For example, as best seen in
As mentioned, repeated contact between the contact surface 60 of the work contact element and the broad side of the shingles during fastening operations may cause wear to the contact surface 60 and contact between the trailing side surface 64 of the work contact element and the ends or narrow edges of shingles during shingle alignment using the shingle gauge may cause wear to the trailing side surface 64 of the work contact element. In order to prevent or limit wear to the contact surface and trailing side surface of the work contact element during use of the fastener driving tool, the base member is provided two protection inserts 74, 76.
The protection inserts 74, 76 have substantially identical cubical configurations. In one embodiment, the inserts are cubes having sides of approximately 5 mm although other sized inserts may be used. The inserts are formed of a wear resistant material. In one embodiment, the protection inserts 74, 76 are formed of a carbide material, such as tungsten carbide, although any suitable wear resistant material may be used. The two protection inserts 74, 76 are sized and positioned in the base member 54 to maximize the protection capability of the two inserts while minimizing cost and complexity of manufacturing and the impact on the structural integrity of the support member.
The protection inserts 74, 76 are positioned in a pair of recesses formed in the base member that are spaced apart along the alignment edge. In one embodiment, the inserts 74, 76 are affixed to the recesses using a brazing process although the inserts may be affixed to the recesses in any suitable manner.
An insert is positioned in a recess so that it extends through both openings associated with the recess. For example, referring to
To enhance the ability of the work contact element to align shingles, the planes R and plane S of insert 74 meet to form a substantially 90 degree angle (i.e., right angle), and the plane T and plane U of insert 76 meet to form a substantially 90 degree angle. The right angles of the exposed edge or corners of the inserts enable the inserts to be used to push against the narrow edge during the shingle alignment process described above in relation to the shingle gauge while minimizing the chance that the inserts and consequently the work contact element of the fastener driving tool slipping over the edge of the shingles as might happen if the inserts had rounded or chamfered corners or edges.
The two protection inserts 74,76 are positioned along the alignment edge 66 of the base member 54 to minimize their impact on the structural integrity of the base member while still providing protection to both the contact surface 60 and the trailing side surface 64 and a stable aligning surface for use when aligning shingles using the shingle gauge. For example, positioning one or more inserts in the alignment edge 66 in front of the ejection orifice 65 may weaken the base member material that is positioned between alignment edge 66 and the ejection orifice 62 making the base member susceptible to cracking or breaking along the edge 66 during use. Accordingly, each protection insert 74, 76 is positioned so as to be on opposing sides of the ejection orifice 62. In particular, referring to
As depicted in
The size of the inserts 74, 76 is selected to minimize the weight added to the base member while still allowing the inserts to provide adequate protection to the contact surface 60 and trailing side surface 64 and a stable alignment surface. In one embodiment, the inserts 74, 76 are sized so that their combined extent along the alignment edge 66 is less than half of the entire length of the alignment edge 66 between the lateral side surfaces 66, 68. In one particular embodiment, the inserts 74, 76 are sized so that their combined extent along the alignment edge is less than one third of the entire length of the alignment edge between the lateral side surfaces. For example, as depicted in
An advantage of positioning the inserts 74, 76 at the alignment edge 66 of the base member 54 and not in the central portion of the leading surface 60 as in some previously known systems is that much of the area of the leading surface 60 is left available for the incorporation of attachment features for removably attaching the base member 54 to the support member 56. In one embodiment, with reference to
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same should be considered as illustrative and not restrictive in character. It is understood that only the preferred embodiments have been presented and that all changes, modifications and further applications that come within the spirit of the invention are desired to be protected.
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