Abstract:
A fastener outlet assembly for a fastener driving tool includes: an outlet passage arranged to expel fasteners from the assembly to a workpiece during use, the outlet passage having one or more walls; and a detector arranged to detect whether a fastener is present in the outlet passage. The detector comprises at least part of a cover that provides at least part of a wall of the outlet passage, the cover being movable with respect to the remainder of the outlet passage to open the outlet passage and gain access thereto.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to fastener driving tools, and particularly concerns such tools and assemblies in which the fasteners comprise nails. Thus, the tool according Co the invention may comprise a nailer. However, the invention also concerns other types of fasteners, including pins, staples, screws, rivets, etc, 
         [0003]    2. Description of the Related Art 
         [0004]    Many fastener driving tools include a driver that is propelled rapidly against a fastener to drive a fastener from the tool into a workpiece. The driver may comprise a piston, or a ram (impact member), for example. The driver may be propelled in any of a variety of ways, including, but not limited to, pneumatically, by combustion, by means of a strap or chain, by means of a separate piston, or by means of one or more flywheels, for example. 
         [0005]    For many years, fastener driving (firing) tools have included a feature whereby a fastener cannot be fired (driven) from the tool unless a nose part of the tool is retracted. This is intended to ensure that the nose part of the tool is pushed against a workpiece, such that the nose part is retracted, before a fastener can be fired from the tool. Some fastener driving tools also include a mechanical detector to detect whether or not a fastener is present in an outlet passage of the tool. If a fastener is not present, a nose part of the tool is prevented from retracting, and thus the tool is prevented from firing a fastener. This is sometimes ret erred to as “dry-fire lock-out”, and is an additional feature intended to ensure that if the tool is fired, the energy generated by the tool is (at least partially) expended in firing a fastener from the tool and does not need to be absorbed by the tool. Fastener driving tools including a fastener detector are disclosed in the following U.S. Pat. Nos.: 3,606,128; 5,167,359; 6,267,284 B1; 7,059,507 B2; and in US Patent Application Publication US 2007/0290019. 
       BRIEF SUMMARY OF THE INVENTION 
       [0006]    The present invention seeks to provide an improved fastener driving tool, and an improved fastener outlet assembly for a fastener driving tool. 
         [0007]    In a first aspect, the present invention provides a fastener outlet assembly for a fastener driving tool, including: an outlet passage arranged to expel fasteners from the assembly to a workpiece during use, the outlet passage having one or more walls; and a detector arranged to detect whether a fastener is present in the outlet passage, the detector including at least part of a cover that provides at least part of a wall of the outlet passage, the cover being movable with respect to the remainder of the outlet passage to open the outlet passage and gain access thereto. 
         [0008]    The cover allows access to the outlet passage, for example in order to allow the user to dislodge a fastener that may have become misaligned in the outlet passage, or in order to allow the user to remedy another type of jam or blockage in the outlet passage. 
         [0009]    In some embodiments of the invention, the detector includes the cover. However, in preferred embodiments of the invention, the detector includes a part, of the cover. The detector preferably is mounted on the remainder of the cover and is movable relative thereto. 
         [0010]    Accordingly, a second aspect of the invention provides a fastener outlet assembly for a fastener driving tool, including: an outlet passage arranged to expel fasteners from the assembly to a workpiece during use, the outlet passage having one or more walls; a movable cover providing at least part of a wall of the outlet passage and being movable with respect to the remainder of the outlet passage to open the outlet passage and gain access thereto; and a detector arranged to detect whether a fastener is present in the outlet passage, the detector being mounted on the cover and movable relative thereto. 
         [0011]    It is to be understood that any feature of any aspect of the invention may be a feature of any other aspect of the invention. 
         [0012]    Preferably, the detector is rotatably mounted on the cover (or on the remainder of the cover). Advantageously, the detector may be arranged to rotate about an axis oriented substantially perpendicular to a longitudinal axis of the outlet passage. Additionally or alternatively, the detector may be siidably mounted on the cover, for example. 
         [0013]    The detector preferably is movable with respect to the remainder of the outlet passage and adopts different positions depending on whether or not a fastener is present in the outlet passage. Advantageously, the detector may be resiliency movable with respect to the remainder of the outlet passage, preferably such that at least a part thereof extends into the outlet passage when a fastener is not present, but is prevented from extending into the outlet passage when a fastener is present. Preferably, the detector is rotatable with respect to the remainder of the outlet passage. Additionally or alternatively, the detector may be siidable (or otherwise movable, e.g. by translational movement) with respect to the remainder of the outlet passage. 
         [0014]    Thus, the detector preferably is arranged to extend at least partially into the outlet passage when a fastener is not present (or is not properly located) in the outlet passage. The detector preferably is arranged such that when a fastener is present (and preferably properly located) in the outlet passage, the detector does not extend as far into the outlet passage, and indeed may not extend into the outlet passage at all. Thus, when a fastener is present (and preferably properly located) in the outlet passage, the detector preferably does not hinder the expulsion of the fastener from the outlet passage. Advantageously, at least part of the detector may comprise at least part of a wall of the outlet passage that is arranged to guide a fastener as it is expelled from the passage. 
         [0015]    In preferred embodiments of the invention, the fastener outlet assembly further includes a nose part that is resiliently retractable with respect to at least part of the outlet passage. Preferably, at least a front portion of the nose part is situated in front of the cover, in a direction of expulsion of fasteners from the outlet passage. Advantageously, the detector may be arranged to prevent the nose part from retracting when a fastener is not present in the outlet passage, and preferably to allow the nose part to retract when a fastener is present. Preferably, the fastener driving tool is prevented from driving a fastener into a workpiece when the nose part is prevented from retracting. 
         [0016]    The detector preferably includes a protrusion that extends out of the outlet passage and is positioned to block the retraction of the nose part when a fastener is not present in the outlet passage, and preferably to allow such retraction when a fastener is present. Advantageously, at least part of the protrusion may be visible from the exterior of the assembly and may serve as an indicator as to whether or not a fastener is present in the outlet passage, e.g. by virtue of its position relative to the cover. 
         [0017]    Preferably, the nose part includes a first elongate part extending backwards from the front portion. The protrusion of the detector may be arranged to block the backwards movement of the first elongate part when a fastener is not present in the outlet passage, for example. 
         [0018]    Advantageously, the nose part may include a second elongate part extending backwards from the front portion. The backwards movement of the second elongate part, when the nose part retracts, may enable the tool to drive a fastener into a workpiece. Thus, the second elongate part may comprise part of the above mentioned mechanism, whereby a fastener cannot be driven from the tool unless the nose part of the tool is retracted. Such a mechanism is intended to ensure that the nose part of the tool is pushed against a workplace (such that the nose part is retracted) before a fastener can be fired from the tool. 
         [0019]    The cover may be rotatable with respect to the remainder of the outlet passage. Preferably, the cover is arranged to rotate about an axis oriented substantially perpendicular to a longitudinal axis of the outlet passage. Additionally or alternatively, the cover may be removable from the remainder of the outlet passage. 
         [0020]    A third aspect of the invention provides a fastener driving tool arranged to drive fasteners into a workpiece, the tool including a fastener outlet assembly according to the first or second aspect of the invention. 
         [0021]    Preferably the fasteners comprise nails and the tool includes a nailer. 
         [0022]    The fastener driving tool may drive or fire fasteners from the tool in any convenient manner. For example, the tool may include one or more (e.g. one or two) flywheels or other inertial members arranged to impart kinetic energy to a driver or other member, to drive or fire fasteners from the tool. Alternatively, the tool may drive or fire fasteners by means of compressed gas and/or combustion, for example. The tool may be electrically or pneumatically powered, or powered in any other convenient manner. Preferably, however, the tool is electrically powered, by mains electricity and/or by means of one or more batteries or other portable electrical powering devices. 
         [0023]    The fastener outlet assembly preferably includes a magazine including one or more supply channels arranged to hold fasteners and supply them to the outlet passage. In some preferred embodiments of the invention, the magazine includes two or more supply channels, for example exactly two supply channels. However, in other embodiments of the invention, the magazine may comprise three, four, five or more supply channels. Preferably, the supply channels are arranged substantially parallel to each other, but other arrangements are contemplated. The supply channels preferably are separate from each other. If the magazine includes two or more supply channels, the assembly preferably includes a channel selector arranged to selectively connect the outlet passage with each respective supply channel of the magazine. 
         [0024]    The part of the outlet passage wall(s) that is provided by the cover may comprise part of the length and/or part of the circumference of the wall(s) of the outlet passage. Thus, the cover may provide at least part of the outlet passage wall(s) in combination with a housing part, and/or a nose part, and/or a channel selector, for example. 
         [0025]    The magazine preferably includes at least one urging assembly arranged to urge fasteners toward the outlet passage, in use. Advantageously, each supply channel of the magazine (if there is more than one supply channel) may include a respective urging assembly. The (or each) urging assembly preferably includes a roll spring. The (or each) urging assembly may generally have a form, including a pusher part which may be resiliency rotatable into, and out of, engagement with the fasteners to be urged toward the outlet passage. Preferably, the (or each) pusher part (which pushes the fasteners) is itself pulled toward the outlet passage, for example by means of a roll spring. Alternatively, however, the pusher part(s) may be arranged to be pushed toward the outlet passage. 
         [0026]    In preferred embodiments of the invention, fasteners held in supply channels of the magazine are arranged to be supplied to the outlet passage by passing through an opening in the channel selector. Preferably, the channel selector provides at least part of the wall(s) of the outlet passage. For example, the channel selector may comprise the opening, at least part of the wall(s) of the outlet passage, and a delivery channel situated between the outlet passage and the opening, by which the opening communicates with the outlet passage. 
         [0027]    The fastener outlet assembly preferably includes a housing part (e.g. as mentioned above), on which the cover is movably mounted (e.g. removably mounted), for example by means of a latch, especially an over-centre latch. The cover preferably is mounted on an upper part (as the tool is used and regarded) of the housing, preferably on an opposite side of the housing to a magazine for the fasteners. 
         [0028]    Advantageously, a channel selector (e.g. as mentioned above) may be at least partially housed in the housing part. The channel selector may, for example, be rotatably arranged in the housing part. Preferably, the channel selector includes at least one protrusion projecting outside the housing part, by which the channel selector can be manipulated. In preferred embodiments of the invention, the channel selector includes two such protrusions, preferably located on opposite sides of the outlet passage. 
         [0029]    As described above, in preferred embodiments of the invention the fastener outlet assembly includes a nose part that provides at least part of the outlet passage. The nose part may include a fixed tubular part, to provide at least part of the length of the outlet passage, preferably arranged forwardly of the cover. Preferably, a retractable portion of the nose part is retractable with respect to such a fixed tubular part, and preferably the tubular part is at least partially contained in the housing part. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0030]    Preferred embodiments of the invention, will now be described, by way of example, 
           [0031]    with reference to the accompanying drawings, of which: 
           [0032]      FIG. 1  shows a fastener driving tool according to the invention; 
           [0033]      FIGS. 2 to 9  are views of a fastener outlet assembly according to the invention, and components thereof; 
           [0034]      FIG. 10  is a view of a cover and detector of a fastener outlet assembly according to the invention; and 
           [0035]      FIG. 11  is a view of a detector of a fastener outlet assembly according to the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0036]      FIG. 1  shows a fastener driving tool  1  according to the invention, including a main body  3 , a driver  5 , a ram  7  attached to a front part of the driver  5 , and a fastener outlet assembly  9  according to the invention, attached, to a front part of the main body  3 , for example by means of screws  11 . As indicated schematically, the fastener driving tool  1  may include two electric motors  13  and two flywheels  15 , each flywheel being powered by a respective motor  13 . Not shown, but provided in a conventional manner, the fastener driving tool  1  includes a handle, a trigger for firing the tool, and a rechargeable (and removable) battery for powering the motors  13 . The fastener outlet assembly  9  includes a resiliency retractable nose part  17 . 
         [0037]    The fastener driving tool  1  is arranged such that when a user wishes to drive or fire a fastener (e.g. a nail) into a workpiece (not shown), the user pushes the nose part  17  of the tool against the workpiece, causing the nose part to retract. This allows the tool to drive a fastener into the workpiece, once the trigger is pulled. The trigger may be pulled before or after the nose part  17  is retracted (but if pulled before the nose part is retracted, the trigger must remain pulled while the nose part is retracted) to cause the fastener to be fired into the workpiece. When the trigger is in a pulled condition and the nose part is in a retracted condition, the electric motors  13  cause the flywheels  15  to propel the driver  5  forward, thereby causing the ram  7  (which is attached to the front of the driver  5 ) to expel a fastener from the tool and fire it into the workpiece. Such firing arrangements are known to persons skilled in the art, and are not described in further detail herein. 
         [0038]      FIGS. 2 to 9  show a fastener outlet assembly  9  according to the invention, and components thereof. As explained above, the fastener outlet assembly  9  is attached to the front of the main body  3  of the fastening driving tool by means of screws  11 . The fastener outlet assembly  9  includes a magazine  19 , a housing part  21 , a nose pan  17 , and a channel selector  23 . A pivotable cover  51  is secured to the top of the housing part  21  by means of an over-centre latch  53 . An outlet passage  26  (from which fasteners are fired from the tool) extends through the nose part  17  and channel selector  23 , and has a longitudinal axis A-A. Both the nose part  17  and the channel selector  23  are partially housed in the housing part  21 . The channel selector  23  is rotationally arranged in the housing part  21 , so that it can rotate about the longitudinal axis A-A of the outlet passage. The channel selector  23  provides part of the circumference of part of the length of the outlet passage  26 , and the cover  51  provides another part of the circumference of that length region of the outlet passage. Thus, the channel selector  23  and the cover  51  in combination provide part of the length of the outlet passage  26 . 
         [0039]    The fastener driving tool  1  shown in the figures is a nail driving tool (i.e. a “nailer”), arranged to fire fasteners in the form of nails  27 . Each nail  27  has a sleeve  29  (e.g. formed from a polymer material) located on at least part of its length. The nails  27  are arranged in strips  31 , with the nails being indirectly connected to each other by means of the sleeves  29 . The strips  31  of nails  27  are arranged in straight lines, with each sleeve  29  frangibly (breakably) connected to two immediately adjacent sleeves (other than the two end sleeves of the strip, each of which is connected to only one sleeve). When an end nail  27  of the strip is fired from the tool  1 , the sleeve  29  located on the nail is forcibly disconnected from its adjacent sleeve by the force of the ram  7  driving the nail  27  forward with respect to the other nails in the strip, and the nail  27  together with its sleeve  29  is fired from the tool. 
         [0040]    The magazine  19 , which preferably is formed from metal and/or polymer material(s), includes an elongate frame that has two separate supply channels for holding two separate strips of nails  31 , one strip in each supply channel. The supply channels are provided on opposite sides (left and right) of the frame of the magazine, divided by a central wall of the frame, and each supply channel is partially open on a side opposite the central wall, so that the nails  27  can be observed (and partially accessed). The frame of the magazine  19  is attached to the housing part  21  by partial insertion therein, and is secured thereto by means of screws. At the opposite end of the magazine, a foot  47  of the magazine is attached to the frame. The end of each supply channel at the foot end of the magazine is open, by means of apertures in the foot, to allow nail strips  31  to be inserted into the supply-channels through the foot  47 . A forwardly arranged end  49  of the foot is substantially level with a forward end of the nose part  17  when the nose part is retracted, to help support the tool against a workpiece when a fastener is being fired from the tool. 
         [0041]    Each strip of nails  31  is urged in its respective supply channel toward the channel selector  23  by means of a respective urging assembly  39  including a fastener feed device  41  including a spring-biased pusher part  43 , and a roll spring (not shown). Each roll spring continuously urges its associated feed device  41  toward the channel selector  23 , because one end of the roll spring is attached to the fastener feed device  41  and the opposite end of the roll spring is attached to the housing part  21 . The roll spring is in a substantially unwound state when the feed device  41  is furthest from the channel selector  23 , and urges the feed device  41  toward the channel selector by its tendency to achieve a fully wound state. The spring-biased pusher part  43  is biased to extend into its respective supply channel, but may be “toggled” (rotated) against a spring bias so that it is substantially clear of the channel. In this way, normally during use the pusher part  43  presses (by virtue of the roll spring) against the rear nail of the nail strip  31 , to urge the nail strip toward the channel selector  23 , but the pusher part  43  may be rotated out of the way to allow a new nail strip  31  to be inserted into the supply channel through an aperture in the foot  47  of the magazine  19 . 
         [0042]    One strip  31  of nails  27  at a time extends from a respective supply channel of the magazine  19  into the outlet passage  26  via the channel selector. In the preferred embodiment of the invention that is illustrated, the channel selector  23  holds three nails  27  at a time, one of which is in the outlet passage  26  of the tool. In other embodiments, the channel selector can hold more, or fewer, nails or other fasteners at a time, for example one, two, or four fasteners. Once one strip  31  of nails  27  (or other fasteners) has been almost fully used up, e.g. so that only three nails remain in the strip (i.e. there are no nails remaining in the supply channel from which the nails have been fed), the user can rotate the channel selector  23  in the housing part  21  about the longitudinal axis A-A of the outlet passage so that it is aligned with the other supply channel of the magazine, i.e. aligned with another strip of nails (or other fasteners) located in the other supply channel. In this way, the magazine  19  can hold approximately twice as many nails (or other fasteners) as would be the case if it included only one supply channel. 
         [0043]    The nose part  17  of the fastener outlet assembly  9  includes a generally cylindrical front portion  55  (from which nails or other fasteners are expelled in use), first  57  and second  59  elongate parts extending backwards from the front portion  55 , and a fixed tubular part  61  which extends forwardly from the housing part  21 . The backwards movement of the second elongate part  59  when the front portion  55  of the nose part retracts enables the tool to drive a fastener into a workpiece. That is, the second elongate part  59  includes part of a mechanism (not shown), whereby a nail (or other fastener) cannot be driven from the tool unless the nose part of the tool is retracted. This mechanism is intended to ensure that the nose part of the tool is pushed against a workpiece (such that the nose part is retracted) before a fastener can be fired from the tool. Such mechanisms are well known to persons skilled in the art (e.g. from the patent publications referred to above), and thus will not be described in further detail herein. 
         [0044]    The cover  51  includes a detector  63  rotatably mounted on an interior surface of the cover (i.e. on an underneath surface adjacent to the outlet passage  26 ). The detector  63  includes an elongate leg portion  65  having a pivot region  67  at one end thereof, and a foot portion  69  at the opposite end thereof. The foot portion  69  has a concave surface  71  which, when a fastener is present in the outlet passage  26 , forms part of the wall(s) of the outlet passage. An opposite surface  73  of the foot portion  69  includes a recess  75  arranged to accommodate a compression spring (not shown) which biases the foot portion  69  to rotate away from the main part of the cover  51  and at least partially into the outlet passage  26 . The detector  63  is arranged to rotate on its pivot region  67  about an axis oriented substantially perpendicular to the longitudinal axis A-A of the outlet passage. When a nail (or other fastener) is not present in the outlet passage  26 , at least part of the foot portion  69  of the detector  63  extends into the outlet passage  26  under the bias of the compression spring. When a nail (or other fastener) is present in the outlet passage  26 , the foot portion  69  of the detector  63  is prevented from extending into the outlet passage, by the nail (or other fastener). 
         [0045]    The detector  63  includes a protrusion  77  that extends laterally out of the outlet passage  26  and is positioned to block the backwards movement of the first elongate part  57  of the nose part  17  when a nail (or other fastener) is not present in the outlet passage, i.e. when the detector is in a position such that at least part of its foot portion  69  extends into the outlet passage. This position of the detector  63  is shown in  FIGS. 4 ,  5  and  6 . However, when a nail (or other fastener) is present in the outlet passage  26 , the foot portion  69  of the detector has been moved out of the outlet passage and thus the lateral protrusion  77  has also been moved out of the path of the first elongate part  57  of the nose part  17 . This position of the detector is shown in  FIGS. 7 and 8 . With the detector  63  in this position, when a user pushes the nose part  17  against a workpiece, the nose part  17  is able to retract, thereby causing the first and second elongate parts  57  and  59  of the nose part to move backwards. This configuration is shown in  FIG. 9 . When the second elongate part  59  is moved backwards, a mechanism of the tool allows the tool to drive a nail (or other fastener) from the outlet passage into the workpiece. 
         [0046]    In the illustrated embodiment of the invention, the lateral protrusion  77  of the detector  63  is located inside the housing part  21 , and thus is not visible from the exterior of the tool. However, in other embodiments of the invention, the lateral protrusion  77  extends to the exterior of the tool and serves as a visible indicator as to whether or not a nail (or other fastener) is present in the outlet passage. 
         [0047]    It will be understood that the above description and the drawings are of particular examples of the invention, but that other examples of the invention are included in the scope of the claims.