|Publication number||USRE39567 E1|
|Application number||US 10/968,818|
|Publication date||Apr 17, 2007|
|Filing date||Oct 20, 2004|
|Priority date||Jul 27, 1999|
|Also published as||US6279808|
|Publication number||10968818, 968818, US RE39567 E1, US RE39567E1, US-E1-RE39567, USRE39567 E1, USRE39567E1|
|Inventors||Mark E. Larsen|
|Original Assignee||Stanley Fastening Systems, L.P.|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (13), Non-Patent Citations (1), Referenced by (2), Classifications (8), Legal Events (2)|
|External Links: USPTO, USPTO Assignment, Espacenet|
1. The Field of the Invention
The present invention relates generally to powered fastener drivers and particularly relates to an improved nail gun having a guide mechanism to facilitate accurate and consistent orientation and placement of nails as the nails exit the nail gun.
2. The Relevant Technology
In the endless pursuit of increased productivity, industry has continuously sought ways to improve worker effectiveness and efficiency. Many traditionally manual functions are now partly or fully accomplished by mechanized means. One of the major advances in the construction industry was the development of powered nail guns. These guns typically drive nails or other fastnerers by means of a driving mechanism which, in turn, is impelled by compressed air, electrical power, or the like. Powered nail guns have numerous advantages, not the least of which is the ability to drive nails or other fasteners in a fraction of the time that would be required for a construction worker using a traditonal hammer. Another important advantage of these guns is their ability to drive a variety of fastener types into a wide range of materials, such as concrete, steel, sheet metal, and wood.
While powered nail guns clearly provide significant advantages in terms of efficiency and versatility, the nail guns are not without their shortcomings. A major problem area concerns the inaccuracy and inconsistency of nail placement and orientation.
In order for nail guns to realize their maximum potential as effective and useful tools, they must be both accurate and consistent in their placement and orientation of nails. Nail guns that shoot nails inaccurately and/or inconsistently are a source of frustration at best, resulting in re-working wasted production time. At worst, inaccurate and/or inconsistent nail guns can cause serious injury to the operator or to others near the work area; the high magnitude of the driving forces utilized by typical nail guns makes the problems of inaccuracy and inconsistency particularly dangerous.
The problems of inaccuracy and inconsistensy in the placement and orientation of nails can manifest themselves in all types of nail guns and with all types of fasteners. However, these problems become especially acute when the nail gun is shooting relatively shorter nails, such as the nails typically used to secure metal joist hangers, ties, and straps; generally, these types of nails are approximately 1¼″ to 2½″ in length.
A major cause of inaccuracy/inconsistency problems relates to the channel defined by the nose of the nail gun. The nose of the gun defines a generally U-shaped channel, inside the nail gun, through which the nails travel, typically, this channel is somewhat larger in diameter than the driven fasteners. As a result of the dimensional differences between the nails and the channel through which they travel, the nails have some freedom to move about inside the channel and thus are prone to tilt back and forth slightly or “tumble” as they are pushed down the channel. Generally, relatively shorter nails are more susceptible to tumbling than are relatively longer nails. Because the typical nail gun has no means to prevent the fasteners from tumbling, the nails tend to exit the nail gun in random orientations. Thus, the nail gun operator can never be completely assured that a particular nail will come out straight, or that the nail will enter the work piece at the point that the operator intended.
As noted earlier, inaccurate and inconsistent nail placement and orientation is, at best, problematic. However, when the operator is using the nail gun to drive nails through holes pre-drilled in metal items such as joist hangers and straps, inaccuracy and inconsistency present serious safety hazards. Specifically, the random placement and orientation of the nails that is typical of many nail guns, coupled with the high energy of typical nail gun drive mechanisms, causes some nails to miss the pre-drilled hole entirely, strike the metal, and ricochet dangerously away.
The dangers presented by inaccurate and inconsistent nail placement and orientation have not gone unrecognized in the field. Efforts have been made to resolve, or at least minimize, the possible effects of inaccurate and inconsistent nail driving when attaching metal members. However, as indicated in the following discussion, these prior efforts fail to completely and effectively resolve the problems.
At least one attempt to resolve the problem of inaccurate and inconsistent nail orientation and placement has placed the primary focus not on the nail gun itself, but rather on the material through which the nail is being driven. In particular, the material, typically sheet metal of some kind, is embossed in such a way that the embossment forms a funnel-shaped indentation centered about each of the holes pre-drilled in the sheet metal. The purpose of the funnel is to guide errant nails towards the hole as the nails exit the nail gun.
The embossed funnel approach is somewhat problematic however. First, it fails to correct the fundamental cause of the inaccuracy and inconsistency problems; that is, the tendency of the nails to tumble as they are being driven. Rather than preventing the tumbling problem, the funnel approach is focused at correcting the effects of tumbling after the tumbling has already occurred. More importantly however, this approach is disadvantageous because of the increased tooling and production costs involved with embossing the metal through which the nail is fastened. Finally, embossed metal fittings are essential to the success of this method; clearly, if the user does not have access to embossed metal fittings or if the fittings are unavailable for any reason, the problems of inaccurate and inconsistent nail placement will persist.
Another of the other attempts at resolving the inaccuracy and inconsistency problems in nail placement and orientation focuses on the nail gun itself. In this case, a specialized nail gun has been developed which allows the tip of the nail to be extended partially from the gun prior to driving. In this way, the user can place the tip of the nail in the hole, and then pull the trigger of the gun to drive the nail. This has proven to be a limited solution however.
The major shortcoming of this approach is that because the “protruding tip” nail gun is specially adapted for the particular purpose of driving nails in metal items, it is not suitable for other applications, such as framing. Thus, a contractor would be required to incur the additional, and substantial, expense of purchasing an extra nail gun for the sole purpose of attaching metal members such as joist hangers.
In view of the aforementioned problems with driving nails in metal members, what is needed is an improved nail gun that will provide both consistent and accurate nail placement and orientation, without requireing special modification of the work piece. Specifically, the nail gun should have a guide mechanism that would prevent the nails from tumbling as they are driven from the nail gun. Further, the guide mechanism should be readily adaptable and field mountable to a variety of conventional nail guns, so as to preclude the need for purchase of a specialized gun. Finally, the guide mechanism should have a pilot or the like to provide the operator with assurance that the gun is properly lined up with respect to the hole in the work piece.
The present invention has been developed in response to the current state of the art, and in particular in response to the aforementioned and other problems and needs that have not been fully or completely solved by currently available nail guns. Thus, it is an overall object of the present invention to provide a nail gun guide mechanism that is well adapted to prevent tumbling of the nails as they are driven, thereby ensuring consistent and accurate placement and orientation of the nails as they are driven into and/or through the work piece. It is a related object of one embodiment of the present invention to provide a nail gun guide mechanism having a pilot to enable the user to quickly and easily determine when the nail gun is desirably situated over the hole in the work piece. It is also an object of one embodiment of the present invention to provide a nail gun guide mechanism that does not require special preparation of the work piece through which the nail is to be driven. It is a further object of one embodiment of the invention to provide a nail gun guide mechanism adapted to be readily attached and removed, in the field, to a variety of different nail guns so as to preclude the need for purchase of an additional, specialized, nail gun.
In summary, the foregoing and other objects, advantages and features are achieved with an improved nail gun guide mechanism for use in facilitating accurate and consistent placement and orientation of nails. Embodiments of the present invention are particularly suitable for use in connection with conventional nail guns capable of driving the relatively short nails typically used to mount metal members such as joist hangers and the like. The nail guide mechanism is attached to the nose of the nail gun so that the guide mechanism is well-positioned to orient and guide the nail as the nail is driven through and/or into the work piece.
In one preferred embodiment, the nail gun guide mechanism is of two piece construction, comprising a mounting bracket and a guide portion. In an alternative preferred embodiment, the guide portion is integral with the mounting bracket. Preferably, the nail gun guide mechanism is secured to the nail gun by means of screws, bolts or the like, so as to facilitate ready removal and/or installation in the field. The guide mechanism includes a biased arm that is mounted to the guide mechanism such that the arm, acting under the influence of the bias, protrudes into the channel of the nail gun thereby exerting a force on each nail as the nails travel down the channel and pass by the arm. Preferably, the force thus exerted acts substantially along the radial axis of the nail so as to push each nail to the bottom of the nail gun channel, thereby ensuring accurate and consistent orientation and placement of each nail. In one preferred embodiment, the force acts on the nail during at least a portion of the time that the nail is being impelled by the driving mechanism.
Preferably, the biased arm pivots about a pin that is secured to the body of the guide mechanism. The bias is imposed on the arm by means of a partially pre-compressed spring, one end of which is attached to the structrue of the guide mechanism and the other end being attached to the upper portion of the arm. Because the spring is only partially pre-compressed, it permits the arm to move in response to changing conditions inside the channel, such as when the nail head passes by the arm.
Finally, one preferred embodiment of the nail gun guide mechanism includes a pilot. The pilot, preferably integral with the guide mechanism, is situated on the guide mechanism in such a way that when the mechanism is mounted to the nail gun, the pilot is located immediately adjacent to the nail gun channel. The tip of the pilot extends slightly past the nose of the nail gun. When the user wishes to shoot a nail, the user inserts the pilot into the hole where the nail is to be driven; the pilot tip is sufficiently small as to readily permit the nail to pass easily into the hole while the pilot is located therein. The close proximity of the pilot to the nail gun channel ensures that the nail will be desirably located, i.e., in the hole, as it exits the nail gun. As noted earlier, the biased arm simultaneously ensures that the nail is properly oriented in the channel; the arm and pilot thus cooperate to ensure that each nail is desirably oriented and located as the nail is driven from the nail gun.
These and other objects, features, and advantages of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.
In order to more fully understand the manner in which the above-recited and other advantages and objects of the invention are obtained, a more particular description of the invention will be rendered by reference to specific embodiments theroef which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be construed as limiting its scope, the invention in its presently understood best mode for making and using the same will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
The present invention relates to an improved nail guide mechanism for nail guns.
With reference to
As indicated in
With continuing reference to
Reference is next made to
Turning now to guide portion 400 of guide mechanism 200, and with reference to
With continuing reference to
Note that while the preferred embodiment discloses nail guide mechanism 200 employing arm 406 biased by partially pre-compressed spring 414, nail guide mechanisms employing any kind of resiliently biased device to create a sufficient orienting force are contemplated as being within the scope of the invention disclosed herien. Such devices include, but are not limited to, a resilient metal cantilever having one end fixed to the guide mechanism and having the free end biased into the channel.
When there is no nail present in guide portion 400, the force imposed by partially pre-compressed spring 414 biases opposing control end 410 of arm 406 into channel 110 so that arm 406 contacts the outer bottom edge 111 of channel 110, as indicated in FIG. 2.
As further indicated in
When a user squeezes gun trigger 104 of nail gun 100, the nail is driven down channel 110 by drive mechanism 106, and impacts opposing control end 410 of arm 406. However, the orienting force imposed on arm 406 by partially pre-compressed spring 414 is, desirably, substantially less than the force imposed upon arm 406 by the nail. Accordingly, the force exerted by the nail on arm 406 overcomes the opposing bias of arm 406 and displaces arm 406 sufficiently to permit the nail to be interposed between arm 406 and the outer bottom edge 111 of channel 110, as indicated in FIG. 6. The responsiveness of arm 406 also permits the head of the nail to readily displace arm 406 to the extent necessary to allow the nail head to pass by arm 406 as the nail exits gun 100.
In one alternative embodiment of the present invention partially pre-compressed spring 414 positions arm 406 such that opposing control end 410 of arm 406 is centered in outer bottom edge 111 of channel 110. In this manner, when a nail is forced by drive mechanism 106 down channel 110 the nail point of the nail is centered in the outer bottom edge 111 of channel 110 to obtain optimal positioning for driving the nail into the work piece.
In one alternative preferred emboidment, partially pre-compressed spring 414 is not pre-compressed. Rather, the undeformed length of an opposing mechanism similar in function to partially pre-compressed spring 414 is such that arm 406 naturally extends into channel 110 and no force is exerted by the opposing mechanism on arm 406 when channel 110 is empty. When a nail travels down channel 110, which process is described in detail above the force of the nail displaces arm 406 and at least partially compresses the opposing mechanism. The opposing mechanism reacts to the compression by exerting a force, i.e., the orienting force, on arm 406. The arm then transmits the orienting force to the nail or fastener.
Due to the resilient nature of partially pre-compressed spring 414 which it is connected, arm 406 is responsive to whatever orientation the nail has assumed, that is, after the nail comes into contact with arm 406, the orienting force transmitted by arm 406 has a natural tendency to orient the nail and/or retain the nail in a desired orientation. In one preferred embodiment, the orienting force acts substantially radially with respect to the nail. Further, in another preferred embodiment, the orienting force positions the nail so that the longitudinal axis of the nail is substantially parallel to the sides of channel 110; the nail is preferably positioned at or near the outer bottom edge 111 of channel 110, as indicated in FIG. 6 and may preferably be centered in the outer bottom edge 111 of channel 110. Note that the magnitude of the force required to orient a nail may vary from one nail to another; the magnitude will depend, at least in part, upon such variables as the speed and attitude of the nail as it enters guide mechanism 200. Accordingly, this invention contemplates a nail guide mechanism that may employ orienting forces of a variety of magnitudes. Still another embodiment of the present invention contemplates an orienting force that is constant in magnitude for nails driven at a consistent speed and attitude.
As noted earlier, partially pre-compressed sorting 414 continuously biases arm 406 into channel 110. As a result, arm 406 transmits the orienting force to the nail during the entire time that the nail is interposed between arm 406 and the outer bottom edge 111 of channel 110. Continuous application of the orienting force, by guide mechanism 200, thus ensures that every nail, regardless of its orientation upon entering guide mechanism 200, exits nail gun 100 in a consistent and predictable orientation. Although one preferred embodiment of the present invention reaches an arm continuously transmitting an orienting force to the nail as the nail passes the arm, this invention also contemplates resiliently biased arm arrangements wherein the arm briefly loses physical contact with the nail after the initial impact of the nail on the arm.
With reference now to
As noted earlier, in one preferred embodiment, the orienting force acts to position each nail 500 outer bottom edge 111 of channel 110 and in one embodiment the nail 500 is centered in outer bottom edge 111 of channel 110; thus, the close proximity of pilot 310 to channel 110 (
As mentioned above, in an alternative embodiment of the present invention, mounting bracket 300 and guide portion 400 are formed as an integral piece as shown in
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.
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|Citing Patent||Filing date||Publication date||Applicant||Title|
|US8220687 *||Apr 21, 2004||Jul 17, 2012||Max Co., Ltd.||Nailing drive guide mechanism for nailing machine|
|US20060157527 *||Apr 21, 2004||Jul 20, 2006||Hiroki Yamamoto||Nailing drive guide mechanism for nailing machine|
|U.S. Classification||227/119, 227/123|
|International Classification||B25C1/00, B25C7/00|
|Cooperative Classification||B25C7/00, B25C1/00|
|European Classification||B25C7/00, B25C1/00|
|Jan 28, 2009||FPAY||Fee payment|
Year of fee payment: 8
|Feb 28, 2013||FPAY||Fee payment|
Year of fee payment: 12