Patent Publication Number: US-7914005-B2

Title: Hand-held setting tool with connection means for a positioning device

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a hand-held setting tool including an actuation switch, connection means for connecting the setting tool to a positioning device and having a counter-coupling element for the positioning device, a structural component, and a mechanical switching link including at least one first switching element displaceable in the structural component along an axis of the setting tool for connecting an actuation element provided on the positioning device with the actuation switch, and a safety device for preventing actuation of the actuation switch of the setting tool at an orientation of the setting tool other than a predetermined orientation. 
     2. Description of the Prior Art 
     Positioning tools of the type described above are used, e.g., at overhead works in case of high ceilings when working is possible only using working platforms or ladders. Setting tools, which can be used with such devices, can be driven with solid, gaseous, or liquid fuels or with compressed air or electricity. 
     U.S. Pat. No. 4,479,599 discloses a positioning and actuation device for a combustion-operated setting tool and including connection means for the setting tool, which is arranged at an end of an elongated holder and is formed as a rod or a bar. The rod or bar is axially displaceable relative to the connection means for actuating the actuation switch of the setting tool that is secured at the connection means via coupling means. For actuating the setting tool, the tool should be placed with its muzzle part against a ceiling and then be displaced in the direction of the ceiling with the holder or rod by the user. 
     Further, the positioning and actuation device has a safety device which prevents the setting tool from being actuated when the muzzle part is oriented exactly in the direction of the force of gravity. For this purpose, the safety device has a blocking member formed as a ball which is guided in a recess formed as a channel and extending in the connection means diagonally to the longitudinal axis of the rod. At an orientation of the tool in the direction of the gravitational force, the ball rolls into the movement path of the rod and prevents a further movement of the rod relative to the connection means and, therefore, prevents actuation of the setting tool secured on the connection means. To this end, the rod has, at its end adjacent to the connection means, a radially circumferential recess into which the ball can fall. 
     The drawback here consists in that the actuation of the setting tool can only be safely prevented when the positioning and actuation device with the setting tool is oriented exactly with the muzzle part facing in the direction of the force of gravity. 
     U.S. Pat. No. 7,014,085 discloses an explosion-actuated setting tool having a housing, an elongated holder projecting therefrom, and a ball-controlled safety locking device which permits the setting tool to be actuated only in a vertical or almost vertical orientation opposite to the force of gravity. The ball of the ball-controlled device is arranged in an annular receiving space between the holder and the housing. 
     However, the drawback of the setting tool of U.S. Pat. No. 7,014,085 consists in that the diameter of the ball defines the maximum movement path of the holder relative to the housing which is available in the release position of the ball and within which all of the necessary functions such as, e.g., initiating of ignition, must be carried out. Therefore, a very high pressing force is needed for this short movement path. 
     Another disadvantage consists in that widely different angles result when the setting tool is lifted upward until released, and when the setting tool is lowered until blocked again; that is, the limiting angle at which a setting process is still possible when the setting tool deviates from a vertical orientation opposite to gravitational force can vary dependent on the changes in orientation of the setting tool prior to actuation. Moreover, when the setting tool is pressed horizontally against a wall or downwardly against a floor by moving the tool up or down, the blocking ball rolls out of its blocking position, and the setting tool becomes inadvertently released. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is a setting tool having connection means for a positioning device and actuation means of the type discussed above and in which the above-discussed drawbacks of the known setting tools are eliminated. 
     Another object of the present invention is a setting tool of the type discussed above in which the safety device provides for actuation of a setting process with remote actuation means in a predetermined angular region of orientation of the setting tool with respect to the vector of the gravitational force, and enables an adequate switching stroke for actuation of the setting tool at a small expenditure of force. 
     This and other objects of the present invention, which will become apparent hereinafter, are achieved according to the invention, by providing a setting tool the safety device of which includes at least three separate channels and at least three blocking members displaceable in the at least three separate channels, respectively, with the first switching element having a recess for receiving the blocking members and which opens toward the structural component, with the at least three channels being inclined with respect to a plane extending perpendicular to the longitudinal axis and with the at least three channel intersecting, in some regions, an axial projection of the switching element in the form of a secant and opening toward the switching element in respective overlapping regions. The intersection of the axial projection of the switching member by the channels in the form of a secant means that the channels do not extend toward the axis of the switching element but rather intersect the axial projection of the switching element along its periphery. 
     The novel features of the present invention insure, on one hand, that a locking position of the safety device is reached not only at a certain orientation of the setting tool but also rotationally symmetrically with respect to the longitudinal axis in other tilting positions that deviate from the predetermined orientation. This is because at least one blocking member always lies in the overlapping region of a respective channel and extends thus, into the recess of the switching element. Thus, e.g., the blocking position is always then actuated when the setting tool is moved in a tilting position to a vertical (i.e., with respect to the orientation in a direction opposite to the vector of the gravitational force) that exceeds the maximum allowable tilting angle. 
     On the other hand, the maximum stroke of the switching member is not determined by the size of the blocking members. Therefore, the function, which is controlled by the press-on path such as, e.g., actuation of the setting tool or displacement of a cartridge in case of a powder charge-operated setting tool, can be determined based on an optimal force-path ratio. Thereby, a need in high pressure forces can be eliminated. It can also be desirable to be able to actuate the setting tool when the positioning device is oriented in the direction of the vector of the gravitational force and/or in a tilting, with respect to this orientation, position. 
     Advantageously, the at least three channels are distributed about the longitudinal axis rotationally symmetrically. Thus, the blocking function provides for actuation of the safety device about its longitudinal axis at the same release angle in each rotational position. 
     Advantageously, the blocking members are formed as pin-shaped members. Thereby, a premature release of the blocking position can be prevented when the device is dynamically displaced against a wall or a floor, and the blocking members have a tendency, because of the occurring acceleration forces, to move out of their blocking position. This is because the pin-shaped blocking members contrary to the ball-shaped blocking members block the release over their entire axial length, thus, preventing the premature release of the blocking position. 
     From the manufacturing point of view, it is advantageous when the switching element is rod-shaped and is displaced in a guide channel of the structural component. 
     It is advantageous, when the at least three channels are inclined to the plane which extends perpendicular to the longitudinal axis, each at an angle between 20° and 50°. This permits, on one hand, a reliable free switching at an orientation transverse to a direction opposite the direction of the vector of the gravitational force or at an orientation slightly inclined to this transverse orientation and, on the other hand, reliably blocks the actuation at an orientation perpendicular to the vector of the gravitational force (horizontal) orientation, or at a dynamic pressure in the direction of the gravitational force. 
     Advantageously, the overlapping region of a channel with respect to the axial projection of the switching element has a depth toward the longitudinal axis, smaller than a diameter of the channel. Thereby, a reliable guidance of the blocking members in the channels is achieved though the intersection of the channels with the axial projection of the switching element or the guide bore for the switching element defines a secant. 
     It is further advantageous when the recess in the switching element is formed as an annular groove closed in both axial directions of the switching element. This insures a good access of the recess for the blocking members and their easy displacement from the channels into the recess for effecting blocking when the setting tool is displaced in a position in which an actuation is not desired. 
     It is further advantageous when the recess in the switching element has walls that limit the recess in an axial direction and that are inclined to the longitudinal axis so that an axial width of the recess diminishes from a radially outer side to a radially inner side. Thereby, the pin-shaped blocking members have, in the blocking position, not a point but linear contact with the inclined walls of the recess. Thereby, the surface pressure in the contact region can be reduced. 
     The novel features of the present invention which are considered as characteristic for the invention, are set forth in the appended claims. The invention itself, however, both as to its construction and its mode of operation, together with additional advantages and objects thereof, will be best understood from the following detailed description of the preferred embodiment, when read with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings show: 
         FIG. 1  a partially exploded, partially cross-sectional view of a hand-held setting tool with a positioning device according to the invention in a non-pressed position; 
         FIG. 2  a cross-sectional longitudinal, parallel to the longitudinal axis, view at an increased, in comparison with  FIG. 1 , scale, of a portion II of the detail of the setting tool according to the invention with the muzzle part of the setting tool facing in a direction opposite the direction of the gravitational force in a non-actuated position and with indication of an actuated position; 
         FIG. 3  a cross-sectional longitudinal view of the detail of the setting tool shown in  FIG. 2  in the non-actuated position; 
         FIG. 4  a cross-sectional longitudinal, parallel to the longitudinal axis, view of a detail of the setting tool shown in  FIG. 2  with a vertical orientation of the muzzle part of the setting tool in a direction of action of the gravitational force in a non-actuated position; and 
         FIG. 5  a perspective view of a detail of the setting tool shown in  FIG. 4 , in a non-actuated position. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIGS. 1 through 5  show a hand-held setting tool  10  according to the present invention and a positioning device  20  with actuating switching means for the setting tool  10  and which can be formed as a modular unit. Such positioning devices  20  are used for elongation of setting tools in order, e.g., to be able to perform an overhead work on ceilings, etc. with the setting tool. 
     The positioning device  20 , which is shown in  FIG. 1 , has a rod-shaped holder  21  provided with a coupling element  28  that cooperates with a counter-coupling element  18  forming part of connection means  16  of the setting tool  10 , for connecting the rod-shaped holder  21  with the setting tool  10 . The coupling element  28  and the counter-coupling element  18  form a releasable connection, so that the positioning device  20  and the setting tool  10  can be assembled together and disassembled. The connection of the coupling element  28  and the counter-coupling element  18  can be formed, e.g., as a threaded or bayonet connection. 
     In addition to the holder  21  shown in  FIG. 1 , one or more elongation parts can be provided which are inserted between the holder  21  and the setting tool  10  and which are provided at one end with a coupling element and at an opposite end with a counter-coupling element. 
     A longitudinal extension of the setting tool  10  and a longitudinal extension of the holder  21  define an axis A of the assembly. 
     The setting tool  10  shown in  FIG. 1  has a setting mechanism arranged in a housing  11 , which can be formed of one or more parts, for driving fastening elements into a constructional component. An actuation switch  13  is arranged on a handle  12  of the setting tool  10  for actuating a setting process. A muzzle part, designated in its entirety by a reference numeral  14 , is arranged on the setting tool  10  in front of the housing  11  and can be displaced relative to the housing  11 . When the muzzle part  14  of the setting tool  10  is pressed against a construction component (not shown in the drawings), the condition of the setting tool  10  changes to a setting-ready state in which a setting process can be actuated by the actuation switch  13 . The setting tool  10  has further a switching link  30  that is operatively connectable, at the connection means  16 , with remote actuation means  40  of the positioning device  20 . 
     The remote actuation means  40  of the positioning device  20  and the switching link  30  serve for connecting an actuation element  24  provided on the holder  21  with the actuation switch  13  of the setting tool  10 . Thus, the actuation element  24  acts as a remote actuation element. 
     The actuation element  24 , which is formed as an elongate sleeve, is guided over a supporting element  23  of a support structure and formed as a hollow bar. As an alternative to an actuating sleeve, an actuating lever could also be used and, e.g., arranged at a grip part at an end of the holder  21  remote from the coupling element  28 . 
     The actuation element  24  is displaceable parallel to the longitudinal axis A relative to the supporting element  23 . A base part  26 , which projects beyond an axial end  27  of the actuation element  24  remote from the connection means  16 , is arranged at a free end  25  of the supporting element  23  or the holder  21  remote from the coupling element  28 . The supporting element  23  is fixedly connected to a coupling element  28  which has a receptacle  48  for a counter-coupling element  18  at its end remote from the supporting element  23 . A support point  45  for a spring element  42  is formed at an end of the coupling element  28  adjacent to the base part  26 . The spring element  42  is supported with its other end against the actuation element  24  by an intermediate element  43  formed as an inner sleeve, and elastically loads the latter in the direction of its initial position which is shown in  FIG. 1 . The intermediate element  43  is fixedly connected to the actuation element  24 . 
     The actuation element  24  is connected to a sleeve-shaped, first switching member  41  of the remote actuation means  40  and which at least partially surrounds a portion  46  of the coupling element  28  that is secured to the supporting element  23 . The first switching member  41  cooperates with a second switching member  49  which is displaceably guided in a guide  44  in the coupling element  28  that is formed as a blind hole. The first switching member  41  is in turn connected to the second switching member  49  by a connection element  47  which extends perpendicular to the longitudinal axis A and is formed as a stud. The connection element  47  extends through a slit-shaped opening (not shown) in the portion  46  of the coupling element  28  which makes it possible for the connection means  47  to be displaced relative to the coupling element  28  and parallel to the longitudinal axis A. 
     Upon connection of the positioning device  20  with the setting tool  10 , the second switching member  49  of the remote actuation means  40  cooperates with pin-shaped first switching element  34  of the switching link  30  of the setting tool  10 , whereby a switching displacement of the remote actuation means  40  at least in one direction along the axis A is transmitted to the switching link  30 . 
     The switching link  30  of the setting tool  10  has, in addition to the first switching element  34  displaceable along the axis A, a second switching element  35  which is formed as a pivot lever. A cam  36 , which cooperates with a first switching element  34 , is provided on the first lever arm, and a third switching element  38  of the switching link  30  is connected to the second lever arm of the pivot lever. The third switching element  38  is formed as a control bar and is connected with a driver  37  of the switching link  30  and which cooperates with the actuation switch  13  of the setting tool  10 . A spring (not shown in the drawings) biases the switching link  30 , together with the driver  37 , into its non-actuated position shown in  FIG. 1  and in which the driver  37  does not apply pressure to the actuation element  13 . 
     The setting tool  10  further includes a safety device designated in its entirety by a reference numeral  50  (see in particular  FIG. 2-5 ) which prevents the setting tool  10  arranged at the positioning device  20  from being actuated via switching link  30  or being remotely actuated by the actuation element  24  of the positioning device  20  in any orientation other than a permitted orientation. The safety device  50  is located between a structural component  33  of a guide structure for the switching link  30 , which in the embodiment shown in the drawings, forms a guide for the first switching element  34  at the connection means  16 , and a switching element of the switching link  30  displaceable relatively the structural component  33  axially along the axis A, which switching element is formed by the first switching element  34  in the embodiment shown in the drawings. The safety device  50  has a recess  51  that is formed as a radial annular groove on the outer surface of the first switching element  34 . The recess  51  opens radially outer or toward the structural component  33 . In the axial direction, the recess  51  is limited by groove walls  52  extending at an angle toward the axis A so that the axial width of the recess  51  diminishes from its radially outer side toward its radially inner side. 
     The safety device  50  further has a plurality of channels  56 , exactly three in the shown embodiment, which are provided in the structural component  33  and are distributed rotationally symmetrically about the axis A (see in particular  FIG. 5 ), and are inclined at angle α from 20° to 50° to a plane E extending perpendicular to the axis A (see in particular  FIGS. 2 and 4 ). The channels  56  have, perpendicular to their longitudinal extent, a circular cross-section. A radially outer end  58  of the channels  56  is open at an outer surface of the structural component  33 , and the radial inner end  57  of the channels  56  is closed. The openings of the channels  56  are closed at their radially outer ends by the housing  11  (see  FIGS. 2 and 4 ). The channels  56  intersect in the form of a secant, in some regions, an axial projection (or the guide channel) of the first switching element  34  and are open toward the first switching member  34  in these overlapping regions  59 . A length L 2  of the channels  56  from its radially outer end  58  toward the overlapping region  59  is greater than a length L 1  of the channel  56  from its inner end  57  toward the overlapping region  59  (see  FIG. 2 ). The overlapping regions  59  of the channels  56  and the axial projection of the first switching member  34  have, toward the axis A, a depth T that is smaller than a diameter D of the channels  56  (see in particular  FIG. 3 ). A blocking member  55   a ,  55   b ,  55   c , which is formed as an elongate, cylindrical pin, is displaceably arranged in each channel  56 . The length L 1  of the channels  56  from the inner end  57  toward the overlapping region  59  is smaller than a length L 3  of the pin-shaped blocking member  55   a ,  55   b ,  55   c  (see  FIG. 2 ). Further, a length L 4  of the overlapping channel  59  in the longitudinal direction of the channel  56  is smaller than the length L 3  of the pin-shaped blocking member  55   a ,  55   b ,  55   c . 
     In the initial position of the setting tool  10  and the positioning device  20  shown in  FIGS. 1-3 , the muzzle part  14  of the setting tool  10  is oriented in a direction opposite the direction of the vector G of the force of gravity (e.g., in a direction of a ceiling). The actuation element  24  and, thereby, the remote actuation means  40  are inactive, and the actuation element  24  is inactive and is displaced into the cup-shaped base part  26  to the maximum distance by the spring element  42 . Therefore, the first switching element  34  is moved into the guide channel in the structural component  33  likewise to the maximum distance ( FIG. 1 ). The second switching element  35  and the rest of the switching link  30  with the driver  37 , following in the direction of stroke, is inactive. 
       FIGS. 2 and 3  show an enlarged view of an area of the setting tool  10  with the safety device  50 , with the setting tool  10  being oriented with respect to the vector G of the gravitational force, as shown in  FIG. 1 . As shown, the pin-shaped blocking member  55   a  is located in the channel  56 , extending radially outer in a region adjacent to the radially outer end  58  and, thus, without blocking the overlapping region  59  between the structural component and the first switching element  34 . The other blocking members  55   b ,  55   c  (in  FIG. 2 , the blocking member  55   c  is located outside of the cross-sectional plane and is, therefore, not visible) are also located radially outer in the respective channels  56  in regions adjacent to respective outer ends  58 , likewise not blocking the respective overlapping regions  59 . The safety device  50  is located at this orientation of the setting tool  10  and positioning device  20  in its actuation-permitting position. The setting tool  10 , which is attached to the positioning device  20 , can be pressed, at this orientation, with its muzzle part  14  against a ceiling or another constructional component and can be actuated by displacement of the actuation element  24  in a direction of the coupling element  28  because the blocking members  55   a ,  55   b ,  55   c  permit a relative movement of the first switching member  34  with respect to the structural component  33  due to their inserted position in the first recess  51 . As shown in  FIG. 2 , the first switching member  34  is displaced axially by the second switching member  49  (shown only in  FIG. 1 ) in direction of a first arrow  15  or in direction of the muzzle part  14  relative to the counter-coupling element  18  (the first switching element  34  is shown with dash lines in  FIG. 2 ). The cam  36  on the second switching element  35  displaces the following portion of the switching link  30  up to the driver  37  for the actuation switch  13  (not shown in  FIGS. 2 and 3 ). Thus, at this orientation of the setting tool  10  relative to the vector G of the gravitational force, it can be actuated. 
     Even when the positioning device  20  is inclined relative to the orientation shown in  FIGS. 1-3 , maximum at about 25°-50°, an actuation is still possible. This is because the pin-shaped blocking numbers  55   a ,  55   b ,  55   c  remain in the regions of the channels  56  adjacent to the radially outer ends  58 . If a pin-shaped blocking member  55   a ,  55   b ,  55   c  would only partially, i.e., with an end, extend in the overlapping channel  59 , the safety device  50  still would remain in its release position, so that the blocking member can be pressed out of the recess  51  in a release position upon application of pressure to groove walls  52  of the recess  51 . 
     In  FIGS. 4-5 , the setting tool  10  (and the positioning device  20  not shown in  FIGS. 4 and 5 ), together with the safety device  50 , is oriented with its muzzle part  14  shown in  FIG. 1  in the direction of the vector G of the gravitational force. As shown, all of the blocking members  55   a ,  55   b ,  55   c  are located in the regions of the respective channels  56  adjacent to the respective inner ends  57  of the respective channels  56 . Therefore, due to the relationship of the length L 3  of the respective blocking members  55   a ,  55   b ,  55   c  to the length L 1  from the inner end  57  for the overlapping region  59 , the blocking members  55   a ,  55   b ,  55   c  at least partially block the respective overlapping regions  59 . Thus, the safety device  50  is in its blocking position at this orientation. If the setting tool  10 , which is attached to the positioning device  20 , is pressed with its muzzle part  14  against a constructional component at this orientation, a setting process cannot be initiated by movement of the actuation element  24  of the coupling element  28  (see  FIG. 1 ). This is because the blocking members  55   a ,  55   b ,  55   c  due to their position in the recesses  51 , in the blocking position, provide only for a very short displacement path of the first switching element  34  relative to the structural component  33 . This very short path is much shorter than that necessary for a switching stroke. 
     At a horizontal orientation of the setting tool  10 , i.e., perpendicular to the vector G of the gravitational fore (not shown in the drawings), at least one of the pin-shaped blocking members  55   a ,  55   b ,  55   c  is located in the blocking position and, thus, prevents a relative movement of the first switching member  34  with respect to the structural component  33   
     In one of the embodiments of channels  56 , not shown in the drawings, the channels  56  can conically expand at their inner ends  57 , whereby the central axis of the blocking members  55   a ,  55   b ,  55   c  would extend at an angle to axes of respective channels  56 . Thereby, upon application of a dynamic pressure to the positioning device  20  with the setting tool  10  in the direction of the vector G of the gravitational force or transverse thereto, the blocking time, during which at least one pin-shaped blocking member  55   a ,  55   b ,  55   c  at least partially blocks the overlapping region  59 , becomes longer because the blocking member  55   a ,  55   b ,  55   c  firstly, should align with respect to the central axis of the channel  56  before it can be withdrawn from the channel  56 . 
     Though the present invention was shown and described with references to the preferred embodiment, such is merely illustrative of the present invention and is not to be construed as a limitation thereof and various modifications of the present invention will be apparent to those skilled in the art. It is therefore not intended that the present invention be limited to the disclosed embodiment or details thereof, and the present invention includes all variations and/or alternative embodiments within the spirit and scope of the present invention as defined by the appended claims.