Abstract:
An automated fastening apparatus that includes a moveable fastening device. The fastening device is preferred provided on a platform that is moveably mounted to a linearly disposed track. A drive mechanism moves the platform and fastening device along at least a portion of the track. A non-moveable fastening device and/or multiple moveable fastening devices may be provided. Portable and non-portable embodiments are disclosed as well as tilt control, electronic sensors and firing interval selection, amongst related features.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 60/104,090, filed Oct. 13, 1998, and having the same title and inventor(s) as above. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to automated mechanisms for applying fasteners. The present invention also relates to the use of such mechanisms in the panelized, modular and manufactured home industries and in related industries. 
     BACKGROUND OF THE INVENTION 
     Historically, the construction of houses and other buildings that incorporate wood or wood like material consisted substantially of building a frame and attaching siding to the exterior of the frame and lathe and plaster or sheetrock to the interior of the frame. Each framing member was installed individually to form the completed frame and the siding and interior cover were then attached one member at a time to a completed frame. 
     In an effort to reduce the cost of home (or other building) construction, manufactured or mobile home techniques were developed. In some manufactured home facilities, whole walls (completed wall frames with exterior sheeting attached, with or without an interior covering) are constructed at once. The walls are then interconnected to form the finished house. Amongst other considerations, manufactured homes decreased costs with more efficient construction techniques, but produced houses that lacked desired variety or customized features. 
     The panelizing industry is emerging as a compromise between “stick frame” construction and manufactured homes. Panelizing techniques attempt to provide customization, while providing some of the efficiencies found in manufactured home production. Panelizing facilities often include an assembly line in which forms for receiving studs are provided. A representative line may include a first station at which the studs are inserted into the form and fastened together into a wall panel frame (of a more manageable length than a manufactured home wall, e.g., often 4-12 feet). At a second station, exterior sheeting such as plywood or particle board may be applied (for an exterior wallbase). At a third and fourth station, respectively, a vapor barrier and siding may be applied, if appropriate. The various wall panels are then transported to a job site where they are lifted into place and secured. 
     Mechanisms used to apply fasteners during panel (or manufactured home wall) fabrication are often referred to as “nail guns” or simply “guns” and various gun arrangements are known. An example of the use of these guns in conventional wall panel formation is as follows. After a wall panel frame has been formed, sheeting or the like (for an exterior wall) is provided over the panel frame and a track assembly having a plurality of fixed position guns mounted thereon is lowered into position. The track is centered over a stud and the plurality of guns is fired causing a fastener to be driven from each gun through the plywood into the stud. The track assembly may then be positioned over the next stud, and the process is repeated. This track assembly with a plurality of guns may be hand-held (by one or more persons on each end) or formed integrally with automated machinery. 
     A disadvantageous aspect of prior art fixed position, multi-gun tracks, amongst others, is that they require a plurality of guns which are the most expensive part of the track assemblies. For example, if it is required to fasten every foot for a wall section eight feet in length, then nine guns are required. If it is required to fasten every 6 or 3 inches, then 17 or 33 guns are required, respectively. As applied to hand-held track assemblies, the provision of a plurality of guns is additionally disadvantageous in that it increases the weight of the assembly. 
     Another disadvantageous aspect of fixed position gun tracks is that since the guns are indeed fixed, it is undesirably difficult and time consuming to change their position to accommodate different panel frame configurations, or different spacing for siding or the like. 
     Other disadvantageous aspects of prior art track assemblies include that they utilize contact firing. Contact firing relies on mechanical activation and mechanical sensors having a higher rate of malfunction than, for example, electrical sensors. Contact fired guns also tend to have nail out problems where guns towards the top and bottom plate of a panel frame run out before “interior” guns that do not fire for window or door openings. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a track assembly that utilizes fewer guns without reduced performance. 
     It is another object of the present invention to provide a track assembly that incorporates an automatically moveable gun. 
     It is another object of the present invention to provide various drive mechanisms for a movable gun and to provide portable and non-portable track assembly embodiments. 
     It is also an object of the present invention to provide an improved gun suspension and to provide photoelectric electric or other non-mechanical sensors to detect various conditions that affect gun movement and firing. 
     These and related objects of the present invention are achieved by use of a track assembly having movable fastening mechanism as described herein. 
     The attainment of the foregoing and related advantages and features of the invention should be more readily apparent to those skilled in the art, after review of the following more detailed description of the invention taken together with the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a plan view of a portable track assembly  100  having a moveable fastener mechanism in accordance with the present invention. 
     FIG. 2 is a side elevation view of the track assembly having a moveable fastening mechanism of FIG. 1 in accordance with the present invention. 
     FIG. 3 is a cross-sectional view of a portion of the track assembly of FIGS. 1 and 2 in accordance with the present invention. 
     FIG. 4 is a plan view of a carriage in accordance with the present invention. 
     FIG. 5 is a perspective view of a track assembly having moveable fastening mechanisms in a non-portable (though moveable) bridge in accordance with the present invention. 
     FIG. 6 is a side elevation view of one of the plurality of carriages of FIG. 5 (without a gun mounted thereon) in accordance with the present invention. 
     FIG. 7 is a side elevation view of one of the plurality of carriages of FIG. 5 (with a gun mounted thereon) in accordance with the present invention. 
     FIG. 8 is a diagram illustrating tilt of track assembly in accordance with the present invention. 
     FIG. 9 is a cross-sectional view of track assembly illustrating both automatically moveable and manually moveable guns in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION 
     Referring to FIG. 1, a plan view of a portable track assembly  100  having a moveable fastener mechanism in accordance with the present invention is shown. Assembly  100  is designed for use in the panelizing industry (and in other industries). In a preferred embodiment, the track assembly has a plurality of parallel tracks (or other shaped longitudinal members)  102 , 103  that are disposed between two handle regions  105 , 106 . A control panel  107  is provided in handle region  105  and a drive motor  108  is provided in handle region  106 . The drive motor is coupled to a drive shaft  110  that preferably runs parallel to tracks  102 , 103 . In use, the assembly is preferably held by two persons (one at each handle region) and placed over a stud such that the stud is centered between the first and second tracks  102 , 103  (see FIG.  3 ). 
     A moveable carriage  150  is provided in tracks  102 , 103  and mounted about drive shaft  110  as discussed in more detail below. Carriage  150  has four wheels  151 - 154 , two of which are positioned in each of tracks  102 , 103 . A fastening mechanism, hereinafter referred as gun  160 , is mounted to carriage  150 . Suitable guns are made by Senco of Cincinnati, Ohio, amongst other commercial vendors. In a preferred embodiment, electrical power, signaling and air pressure are provided to gun  160  by suitable electrical conduits and air hoses (also shown in FIGS.  2 - 3 ). Electrical power is initially delivered on cord  109  and air pressure is input on hose  114 . As discussed in more detail below, appropriate electrical conduits and air hoses are provided in housing  139  and harness  135 . 
     In accordance with the present invention, gun  160  is moved across tracks  102 , 103  and is programmed to fire at specific intervals. Gun movement, as alluded to above,.is achieved with a rotatable drive shaft that is coupled to a friction drive within carriage  150 . Rotation of shaft  110  in a first direction causes carriage  150  to move forward from handle region  105  and rotation of shaft  110  in the opposite direction causes carriage  150  to move backward towards handle region  105 . 
     A photo-electric sensor  157  is mounted on carriage  150 . This sensor senses reference holes  113  formed in a top surface of track  103 . In a preferred embodiment, the holes are spaced three inches apart and the gun is programmed to fire on every hale, every other hole, every third hole or every fourth hole, etc., thereby providing fasteners every three, six, nine or twelve inches, etc. Control knobs  116  permits selection of a desired fastener interval. Control knob  117  provides off, jog (gun movement, but no fire), and run (gun movement and fire) settings. 
     An operator at handle region  105  can move the gun forward or backward by depressing an appropriate control button  111  or  112 , respectively. These buttons are coupled to drive motor  108  and determine which direction the drive shaft is rotated. 
     A three phase transformer  121  is preferably provided in handle region  105  for converting a standard 110 volt single phase A/C signal into a three phase signal. A three phase power signal is beneficial in that there are more commercially available three phase motors and they generally perform better than single phase motors. A suitable converter is made by Boston Gear. A speed control unit  123 , also made by Boston Gear, provides factory set (or otherwise selected) control of the speed of the drive motor and hence the carriage. 
     Operation of track assembly  100  is controlled by a programmable microcontroller  122 . Standard industrial programmable controllers and programming techniques therefor are known in the art. Inputs to controller  122  include buttons  111 , 112 , control knobs  116 , 117 , photo-electric sensor  157 , and four other photo-electric sensors (two on the carriage  183 , 184  and one each  127 , 128  at the handle regions  105 , 106 ) that are discussed, below. Outputs include drive motor and air gun firing solenoid control signals. It should be recognized that remote triggering of nail guns (utilizing an air solenoid, etc.) is known in the art. A suitable programmable controller is made by Siemens. 
     Photo-electric sensors  127 , 128  are preferably located proximate handle regions  105 , 106 , respectively. These sensors provide an interrupt signal that stops the carriage from running into the handle regions. 
     Referring to FIG. 2, a side elevation view of the track assembly having a moveable fastening mechanism of FIG. 1 in accordance with the present invention is shown. FIG. 2 illustrates many of the features shown in FIG. 1, including handle regions  105 , 106 , control button  116 , track  102 , harness  135 , carriage  150 , gun  160  and drive motor  108 , amongst other components. In addition, FIG. 2 illustrates an electrical conduit  132  (removed in portion to show carriage  150 ), a gun tower  170  and an additional perspective on how carriage  150  fits within tracks  102 , 103 , amongst other features. 
     Electrical conduct  132  provides three phase electrical power from transformer  121  to drive motor  108 . The conduit is preferably provided along track  102  generally as shown and may be attached with brackets or the like. An electrical conduit  137  is also provided between transformer  121  and gun tower  170 . An air hose  138  from input hose  114  is provided along with electrical conduit  137 . The conduit and hose  137 , 138  are provided in a housing  139  along track  102  and in flexible cable and hose harness  135  that extends above the track and permits movement of the gun along the track. Suitable cable and hose harnesses and conduit arrangements are known in the art. Signal and control lines (from/to controller  122 ) are also preferably provided in housing  139  and harness  135  via a 12-line strip cable  136  (FIG.  3 ). 
     Gun tower  170  is configured to accommodate different sized guns. The tower consists of an internal vertical portion  171  (shown in plan view in FIG. 4) on which exterior portion  172  is mounted. The height of the exterior portion can be raised by removing pin  173 , raising the exterior portion and re-inserting pin  173  through aligned holes. Gun  160  is secured to a mounting bracket  174  that is coupled to exterior portion  172 . Air bellows  175  are provided between gun  160  and exterior tower portion  172  to provide shock absorption for gun  160 . The bellows are preferably inflated to provide adjustable pressure against the mounting bracket. The mounting bracket is preferably screwed to the exterior tower portion and the gun  160  is preferably screwed to the mounting bracket. 
     Referring to FIG. 3, a cross-sectional view of a portion of track assembly  100  of FIGS. 1 and 2 in accordance with the present invention is shown. Tracks  102 , 103  are configured to have guide protrusions  141  in which wheels 151-154 of carriage  150  are received and a lip for added rigidity. The wheels are further aligned by portion  142  that descends into a central groove of the wheels. 
     Housing  139  preferably extends from track  102  and houses cable  136 , conduit  137  and hose  138 . A top of housing  139  provides a surface  143  for receiving harness  135  (shown in phantom lines) when gun  160  nears handle region  105 . Lip  144  provides a barrier and rigidity for surface  143 . One of the plurality of reference holes  113  is shown in the top of track  103 . Carriage  150  includes axles  156  that extend into each wheel. A friction drive  180  is provided in carriage  150  as described in more detail below with reference to FIG.  4 . The drive shaft  110  is provided through friction drive  180 . 
     FIG. 3 also illustrates that when used to attach sheeting  68 , the tracks  102 , 103  are preferably centered over the stud  72  to which the sheeting is to be attached. 
     Referring to FIG. 4, a plan view of carriage  150  in accordance with the present invention is shown. FIG. 4 illustrates carriage  150  without gun  160 , exterior tower portion  172 , harness  135  and related components such that other features of carriage  150  can be better viewed. FIG. 4 illustrates the arrangement of friction drive  180  within carriage  150  and the insertion of drive shaft  110  through the friction drive. Photo-electric sensors  183 , 184  are also shown. These sensors detect whether there is a substrate (i.e., wood) underneath gun  160 . The sensors are coupled to electrical conductors within cable  136 . A sensor is provided for each direction of movement. If a substrate is not detected within a predefined distance (of approximately 1-2 inches) of the appropriate sensor (based on direction of movement), then the firing signal is interrupted. Wheel  178  is preferably mounted to carriage  150  or alternatively to mounting bracket  174 . If one wheel is provided, it is preferably positioned parallel to and centered with the nozzle of the nail gun. 
     Referring to FIG. 5, a perspective view of a track assembly  200  having moveable fastening mechanisms in a non-portable (though moveable) bridge  201  in accordance with the present invention is shown. Track assembly  200  includes many of the features of portable track assembly  100 , yet incorporates them in a more heavy duty, increased performance apparatus. Track assembly  200  includes a plurality of moveable guns  260  that are each mounted on a carriage  250  (discussed in more detail below with reference to FIGS.  6 - 7 ). A small plurality of moveable guns provides the benefits of the single moveable gun assembly discussed above, with the benefit of faster performance because of multiple guns. A first ( 205 ) and second end plate (only one of which is shown due to the perspective of the drawing) are provided in the vertical support members  207 , 208  of the bridge. These plates are simultaneously moved up and down preferably with air pressure via cylinders  209  as is known in the art. 
     In a preferred embodiment, a plurality of horizontally arranged support rods (analogous to tracks  102 , 103 ) are provided between the two end plates. The top and bottom rods  202 , 203  have a smooth outer surface and serve as guide rods. The center rod  210  is preferably threaded and coupled to a drive motor  208  (similar to drive motor  108  discussed above). The center rod is the drive rod and it is threaded through two complementary ball screws  280  provided on each side of each carriage  250  as discussed in more detail below with reference to FIG.  6 . 
     Track assembly  200  includes a back panel  215  that is preferably coupled between the two end plates. Additional housing members may be provided about rods (or track members)  202 , 203 , 210  as is known. These additional members, however, are not shown in FIG. 5 so that the interior components of the track assembly may be seen. A reference bar  214  having a plurality of reference holes  213  (like reference holes  113 ) is preferably provided on the back panel or suspended from the horizontal member of bridge  201  or the like. A photo-electric sensor  257  in the center carriage detects each hole  213  as the center carriage  250  passes by. The three carriages are preferably arranged at fixed, equal distances and configured to fire substantially simultaneously. They are further configured to cover contiguous sections such that a reference bar for one of them suffices for all three. Guns  260  are programmed to fire at every hole, every second hole, every third hole, or every fourth hole, etc., in the manner discussed above for the portable track assembly  100 . Conduit and air hose harnesses  235  provide electrical power, signaling and air pressure to lo each of the carriages also as discussed above. 
     A programmable microcontroller  222  is provided in vertical member  208 . Controller  222  operates in a manner analogous to controller  122 . Control panel  210  permits operator input. Control of air cylinders and techniques for the remote firing of air guns are known in the art. 
     Each of the carriages  250  includes a nail reservoir  265 . In a preferred embodiment, the nails are arranged in each reservoir in a spool or the like that runs out linearly. A photo-electric sensor  266  coupled to controller  222  is preferably provided adjacent to each nail supply in such a manner as to provide a nail out warning signal. A nail out warning system, permits nail supplies to be replenished before a nail out situation arises. 
     Referring to FIG. 6, a side elevation view of one of the plurality of carriages  250  of FIG. 5 (without a gun mounted thereon) in accordance with the present invention is shown. Amongst other features, FIG. 6 illustrates that drive rod  210  is threaded. Drive rod  210  is inserted through two ball screws  280  on opposite sides of the carriage. Rotation of shaft  210  causes lateral movement of carriage  250 . Suitable ball screw arrangements are known in the art. The ball screws and threaded shaft illustrate an alternative manner of propelling a carriage. To provide additional support to carriage  250 , a plurality of bushings  281  are provided on each of the smooth surfaced guide rods  202 , 203 . 
     Referring to FIG. 7, a side elevation view of one of the plurality of carriages  250  of FIG. 5 (with a gun mounted thereon) in accordance with the present invention is shown. Gun  260  is preferably coupled to a mounting bracket  274  that is in turn mounted to an exterior lo portion  272  that is generally vertically disposed. Air bellows  275  provide shock absorption. First and second photo-electric sensors  283 , 284  (analogous to sensors  183 , 184 ) are provided in addition to support wheels  278 , 279  that preferably ride on the surface of the wood or other material during operation. Wheels  278 , 279  are preferably placed in line with the nozzle of the gun. 
     Referring to FIG. 8, a diagram illustrating tilt of track assembly  200  in accordance with the present invention is shown Referring also to FIG. 5, bridge  201  preferably includes an air cylinder  289  or the like in each vertical member that rotates or tilts its corresponding end plate up to five degrees on either side of vertical. This tilt feature (illustrated in cross section in FIG. 8) permits the secure fastening of two sheets of material  67 , 69  onto a single stud  71 . In conventional track assemblies, that fire straight down, it is possible to split the stud (or a portion thereof) as a result of firing too close to the edge of the stud. The tilt feature of the present invention provides significantly less risk of splitting or otherwise fracturing the underlying stud. Tilt control is achieved via control panel  210  and controller  222  using conventional techniques. 
     Referring to FIG. 9, a cross-sectional view of track assembly  200  illustrating both automatically moveable and manually moveable guns in accordance with the present invention is shown. FIG. 9 illustrates rods  202 , 203  and  210 , moveable carriage  250 , gun  260 , ball screw  280  and bushings  281 . On, for example, the other side of panel  215  or otherwise coupled to or positioned relative to end plate  205 , two additional rods  292 , 293  may be provided. A set of bushings  291  are coupled to a carriage  295  and rod  292 , 293  are fed through the bushings. Clamps  297  (or thumb screws of the like) are provided through the bushings or elsewhere in carriage  295  to permit an operator to releasably secure carriage  295  to rods  292 , 293 . In this manner, gun  296  can be placed in a desired position and secured there. If four guns  296  are provided in this manner then they may be adjusted to insert fasteners into the top plate, window/door header, window sill and bottom plate of a panel frame, i.e., in the direction generally perpendicular to the direction in which automatically moveable guns  260  insert their fasteners. In addition, a drive shaft  298  and a friction drive or ball screw or the like  299  can be provided to move one or more of carriages  295 . For example, this would permit automatic movement of the gun that fastens the top plate when the wall height varies between panels. 
     While the invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modification, and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth, and as fall within the scope of the invention and the limits of the appended claims.