Fastening element feed mechanism for an explosion charge-driven setting gun

Abstract

In an explosive charge-driven setting gun using a piston for inserting fastening elements into a receiving material, a feed mechanism is pivotally connected to the gun body so that it can selectively position fastening elements in alignment with the muzzle opening in the gun body and move the piston into the firing position. The feed mechanism forms a guideway for a magazine holding the fastening elements and a pawl in the feed mechanism moves the magazine for positioning the fastening elements in alignment with the muzzle opening. During each complete cycle of pivotal movement of the fastening mechanism, a fastening element is moved into the firing position and the pawl is displaced for moving the next fastening element into the firing position. SUMMARY OF THE INVENTION The present invention is directed to an explosive charge-driven setting gun for inserting fastening elements, such as bolts, nails and similar anchoring elements, into a receiving material, preferably a hard receiving material, and, more particularly, it concerns the arrangement of a feed mechanism pivotally connected to the body of the setting gun so that fastening elements held in a magazine positioned within the feed mechanism can be moved into alignment with the muzzle opening in the gun. Primarily to save time, there has been an increasing use of fastening element feeding devices with setting guns. As a rule, special setting guns are employed with mechanisms for feeding the fastening elements, held in a magazine, into the muzzle opening of the gun. Setting guns which utilize a piston represent a safe and widely used type employed in combination with feeding mechanisms. For transmitting the driving energy from the explosive charge to the fastening element, the axially displaceable driving piston is used and it remains in the gun during the fastening process. Since the driving piston must be positioned before each fastening operation from a forward position in the gun rearwardly into the firing position, such guns are normally provided with a manually operated piston return device. The mechanism for feeding the fastening elements into the gun muzzle has been separate from the piston return device. It has been known to use setting guns which have a channel in the range of the muzzle which extends perpendicularly to the axis of the bore through the gun and serves to feed the fastening elements, held in a magazine, into the muzzle. However, the magazine feed has been effected manually and, as a result, is particularly time-consuming. Other setting guns have been available which use a feed mechanism arranged on the gun barrel at the muzzle end and ensures a timed feed of the fastening elements held in a square loading magazine, into the muzzle of the gun. In this type of setting gun, the feed of the magazine is accomplished by a relatively complicated mechanism as the muzzle of the gun is pressed against the receiving material. In these known setting guns, the return of the driving piston into the firing position is effected in an operation separate from the feed of the magazine. In addition to a considerable loss of time, the separate operations usually cause considerable technical difficulties. If, by mistake, the driving piston is left in its forward position instead of being returned into the firing position, and the muzzle of the gun is pressed against the receiving material, the piston will block the feed of the magazine and will result in damage to the feed mechanism. Another problem can develop in the known setting guns if the driving piston is returned to the firing position and the magazine is advanced the necessary amount to locate the next fastening element in position if there is no fastening element at that particular position for insertion into the muzzle end of the gun. Under such circumstances, if the explosive charge is detonated, there is no fastening element to stop the forward movement of the piston and considerable damage may result to the setting gun. Further, the magazine and other parts of the setting gun may be damaged if the piston is driven from the firing position and the magazine has not been advanced a sufficient distance to locate a fastening element in the path of the piston. As a result, the piston will strike against the body of the magazine and cause it to be damaged. Therefore, it is the primary object of the present invention to provide a setting gun with automatic feed of the fastening elements which avoids the above-listed disadvantages. In accordance with the present invention, a feed mechanism is mounted on the setting gun so that it can be pivoted into a firing position with a fastening element inserted into the muzzle of the gun so that it moves the driving piston into its firing position. A control member within the feed mechanism assures the accurate feed of the magazine so that the fastening elements are aligned with the muzzle opening of the gun. If the muzzle of the gun is pressed against the receiving material, the feed mechanism pivots into position so that a fastening element is aligned with the axis of the bore forming the muzzle. At the same time, the control member within the feed mechanism moves in the direction opposite to the feeding direction of the magazine by an amount equal to one stroke, that is the distance between two adjacent fastening elements in the magazine. As the feed mechanism is swung in toward the gun body, the fastening element to be driven into the receiving material, is inserted into the muzzle opening and displaces the driving piston rearwardly into its firing position. As a result, a special piston return device or a manual return is unnecessary. If there is no fastening element in the magazine as the feed mechanism is moved inwardly toward the setting gun body, the driving piston is not displaced rearwardly into its firing position. Upon detonation of the explosive charge, the propellant gases do not drive the piston forwardly and no damage can result to the gun or the magazine. To assure that the fastening element is properly centered on the forward end face of the piston, it is of particular advantage if the turning radius of the fastening element to be inserted into the muzzle is as large as possible. For facilitating the introduction of the fastening element into the muzzle opening, it is helpful if the muzzle opening has a larger diameter than the remainder of the bore through the gun. If the setting gun does not utilize a driving piston, the fastening element is positioned in the muzzle in the same manner and is located in its firing position. Preferably, the feed mechanism includes a housing forming a guideway for the magazine and at least a portion of the control member extends into the guideway for engagement with the magazine. Further, the housing is shaped to mate with the muzzle end of the gun and it has an opening through which the fastening element and any part of the magazine attached to it can pass during the firing or insertion step. In such an arrangement, adapted particularly to the magazine form, trouble-free operation of the setting gun is ensured to as great an extent as is possible, since the control member is protected against mechanical damage and fouling. To effect a proper shearing of the disposable magazine in the region surrounding the fastening elements, it is preferable if the edges of the opening in the housing, through which the element is driven, are sharp. In the feed mechanism housing, a longitudinal channel is associated with the guideway for the magazine so that the fastening elements positioned in and extending through the magazine, such as in strip-type magazines, can be passed through the housing along with the magazine. In most of the presently known magazines, the fastening elements are arranged perpendicularly to the feeding direction of the magazine. Accordingly, to position the fastening elements properly in the firing position, after the feed mechanism has been pivoted in front of the muzzle opening of the gun, the guideway extends perpendicularly to the axis of the muzzle opening in the gun. Another feature of the invention is the axial displaceability of the control member within the feed mechanism. Such displaceability affords a particularly slim and convenient design of the feed mechanism. However, rotatable or pivotal control members can also be used. To provide for the automatic feed of the magazine, one or a number of levers disposed in operative engagement with the control member, are connected to the setting gun and to the feed mechanism for actuating the control member as the feed mechanism is pivoted relative to the gun body. A strap connected at one end by a pin to the control member in the feeding mechanism and at its other end to another pin in the setting gun body, affords a particularly suitable lever. The connecting points of the lever are preferably located between the fulcrum of the feed mechanism and the muzzle opening in the setting gun. Preferably, the lever is pivotally mounted on the setting gun and the feed mechanism so that it can be displaced parallel to the direction of motion of the control member in effecting the movement of the magazine through the feed mechanism. The pivotal movement of the lever is assured by the pin connections to the setting gun and the feed mechanism, while the parallel displacement of the lever is achieved by mounting the pin connecting the lever to the feed mechanism within an elongated slot extending in the direction of movement of the magazine through the housing. The length of the slot is selected so that it corresponds to the length of the stroke or feed path of the control member and to the spacing of the fastening elements in the magazine which is the same as the spacing of the recesses in the sides of the magazine into which the control member fits. Accordingly, as the feed mechanism is pivoted relative to the gun body, the lever moves the control member back and forth by the amount sufficient to feed a fastening element for the extent of one spacing in the magazine. The control member is provided as a single or multiple pawl with a finger which engages in the recesses provided in the magazine for moving it in the feeding direction. For reasons of space, it is preferable to use a flat bar for the pawl with a angularly bent portion at its end for engagement within the recesses in the magazine. To ensure the accurate feed of the magazine so that a fastening element is aligned in front of the muzzle opening in the setting gun, the angularly bent end of the pawl is located in that portion of the feed mechanism adjacent the opening in it through which the fastening elements are driven into the receiving material. However, it is also possible to locate the angularly bent end of the pawl remote from the opening through the feed mechanism and to provide the magazine with an extension for guiding the feeding operation. The question of the location of the angularly bent end of the pawl is irrelevant if an endless fastening element magazine is used. The positive engagement of the control member with the recesses in the magazine is assured by utilizing spring elements which bias the control member toward the magazine. However, the same effect can be obtained, for example, by an elastic pawl or by a rigid pawl having an elastic angularly bent end or finger which engages the recesses in the magazine. In the interest of a compact design and high efficiency of the feed mechanism, it is preferable if a leaf spring is used as the spring element for biasing a rigid pawl. Though the leaf spring is preferred, other types of springs can also be used, for example, coil springs. To lock the magazine in position as the control member is being moved from one recess in the magazine to another, locking means are mounted within the feed mechanism housing for engagement in the recesses in the magazine. An additional advantage is obtained by the use of the locking means in that the magazine is held against a side wall of the guideway through the housing and assists in the exact positioning of the magazine. By locating the locking means adjacent the opening from the feed mechanism housing through which the fastening elements are driven, it is possible to ensure that the end section of the magazine is held in position during the firing operation. One or a number of ball catches are suitable for use as the locking means. Such locking members ensure, on the one hand, an exact and to a great extent adjustable locking device, and, on the other hand, afford extremely low friction displacement of the magazine. Effective operation of the gun is possible if a return element is associated with the feed mechanism for returning it into a position angularly spaced from the muzzle opening in the gun. In limiting the displacement movement of the feed mechanism from the firing position, the slot in the feed mechanism housing, through which the pin connecting the lever to the control member extends, is particularly effective. Additionally, special stop means associated with the feed mechanism and with the setting gun can be used for the same purpose. A coil spring is suitable as the return element, preferably a tension spring. Other types of return elements can also be used which employ a tensioning, a shearing or a rotary force. The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated and described a preferred embodiment of the invention .

Description

BRIEF DESCRIPTION OF THE DRAWING

In the drawing:

FIG. 1 is a view, partly in section, of the combination of a setting gun and a feed mechanism in the inoperative position;

FIG. 2 is a sectional view through the feed mechanism taken along the line II--II in FIG. 1; and

FIG. 3 is a sectional view through the feed mechanism taken along the line III--III in FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 1 the setting gun consists of a gun body 1 having a muzzle 2 forming a muzzle bore 3 through which a driving piston 4 is axially displaceable. A feed mechanism 5 contains a disposable magazine 6 and is connected to the gun body by a lever 7. In addition, the feed mechanism 5 is pivotally connected to the gun body 1 by a bearing pin 8 located on the opposite side of the lever from the muzzle 2. A journal 9 is located on the lever 7 and another journal 11 is positioned on the feed mechanism 5 and a tension spring 12 is connected to and extends between the journals and biases the lever 7 in a counter-clockwise direction about a pin 13 mounted on the gun body. The spring-loaded lever 7 is connected to the feed mechanism 5 by means of a pin 14 which extends through a slot 15 in the housing 5a of the feed mechanism. Due to the spring-loading action on the lever 7 the feed mechanism is normally held in an inoperative position pivoted outwardly from the gun body, note FIG. 1.

In FIG. 2, it can be observed that the pin 14 extends inwardly into the housing 5a and a pawl 16 is secured on the inner end of the pin. The pawl 16 is located in a longitudinal recess 18 formed by the combination of the housing 5a and a plate 23 secured to the housing by screws 22. At the opposite end of the pawl 16 from its connection to the pin 14, a finger 17 angularly disposed to the main body of the pawl extends into a recess 19a in the magazine 6, the recess 19a is one of a similar number of recesses spaced longitudinally apart in the edges of the magazine. Within the recess 18, a leaf spring 21, associated with the pin 14, bears against the inside surface of the plate 23 and biases the finger 17 of the pawl 16 into engagement with the recess in the magazine 6. As can be seen in FIG. 3, the magazine is directed through the housing 5a of the feed mechanism 5 through a longitudinally extending guideway 24 and channels 25 extending normally to the guideway 24 and in communication with it afford passage of nails 26 held in the magazine 6 and spaced apart in the feeding direction. In the lower end of the housing 5a, as viewed in FIG. 2, a spring-loaded ball catch 27 engages in one of the recesses 19 in the magazine and holds it in position. The ball catch 27 is located at the end of the housing 5a which swings or pivots in front of the muzzle 2 of the gun body 1.

If the muzzle 2 of the setting gun is moved into engagement with the receiving material, the feed mechanism 5 is pivoted from the inoperative position shown in FIG. 1 inwardly toward the muzzle 2. As the housing 5a pivots toward a position where the guideway 24 is disposed substantially perpendicular to the axis of the muzzle bore 3, the slot 15 similarly changes orientation, and the movement of the housing causes the pin 14 to be displaced upwardly through the slot carrying the lever 7 with it. As a result of the upward movement of the pin 14, the pawl 16 mounted on it is moved out of the recess 19a and is displaced a distance opposite to the feeding direction equal to the amount of movement of the pin through the slot so that the finger 17 rides along the edge of the magazine until it engages into the next recess 19b, located above the recess 19a as illustrated in FIG. 2. During the movement of the pawl 16, the leaf spring 21 is compressed toward the wall 23 and the pin 14 is displaced in its axial direction an amount equal to the depth of the recesses 19 in the edge of the magazine 6.

During the movement of the pawl 16, the magazine is held in position within the guideway 24 by the ball catch 27.

As the housing 5a of the feed mechanism 5 swings inwardly toward the muzzle 2 of the gun, the head of the nail 26a, held in position to be driven from the magazine, strikes against the end face of the driving piston 4 and pushes it rearwardly into the gun body until it reaches its firing position.

To assure that the head of the nail 26a positively finds its way into the muzzle bore 3, a centering cone 28 is provided at the opening of the muzzle. When the feed mechanism is fully pivoted inwardly toward the gun body, the longitudinal axis of the guideway 24 extends normally of the axis of the driving piston 4 and the nail 26a is parallel to the driving piston axis.

With the driving piston in the firing position and the nail 26 aligned with it and ready to be inserted into the receiving material, an explosive charge is detonated within the gun body 1 driving the piston forwardly against the head of the nail for propelling the nail into the receiving material. During the driving action, the piston pushes the nail 26a through the receiving bore 29a in the magazine. As the nail moves forwardly, its head strikes against the surface of the magazine surrounding the bore 29a and the disc-like portion 33a of the magazine surrounding the nail is separated from the rest of the magazine body, and the separating action is facilitated by the arcuate slots 31a formed in the magazine body radially outwardly from the bore 29a and by the sharp-edged shoulders 32 on the housing 5a which define the edges of the opening 34 in the housing through which the nail passes as it is inserted into the receiving material. The driving operation is completed as soon as the disc-like portion 33a or the nail head strikes against the receiving material. With the nail inserted into the receiving material, the driving piston 4 is located in the position as shown in FIG. 1.

After the completion of the driving operation, the setting gun is withdrawn from the receiving material. As the setting gun is withdrawn, the force which moved the feed mechanism 5 into the firing position is released and the force of the tension spring 12 acting on the lever 7 displaces the pin 14 through the slot 15 and pivots the feed mechanism outwardly from the muzzle 2 into the position illustrated in FIG. 1. During the downward movement of the pin 14 through the slot 15, the pawl 16 attached to the pin is moved in the feeding direction and its finger or angularly bent end 17 seated within one of the recesses 19 in the magazine, moves the recess from the recess position 19b to the recess position 19a which distance is the center-to-center spacing between the fastening elements 26a, 26b, note FIGS. 1 and 2. Accordingly, the next nail 26b in the magazine is moved into position to be driven into the receiving material by the piston 4 and the magazine is locked in this position by the ball catch 27. As the nail 26b is moved forwardly, the disposable part 35 of the magazine 6 is moved out of the feed mechanism 5.

Setting guns of this type are especially suited for fastening element driving operations at locations to which access is difficult, such as attaching plates to the inner wall of a chill mold. When the setting gun is used in such an operation, it is provided with a combined supporting and operating bar 36, note FIG. 1, which facilitates the positioning of the gun at the more or less remote point of insertion of the fastening element. If necessary, the center of gravity of the feed mechanism can be arranged on the bar 36.

While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

Claims

What is claimed is:

1. Explosive charge-driven setting gun for inserting fastening elements, such as bolts, nails and the like into a receiving material, preferably a hard material, including a gun body having a muzzle opening, driving means mounted within said gun body and displaceable through said muzzle opening from a driving position rearwardly of said muzzle opening for inserting fastening elements one at a time into the receiving material, a feed mechanism arranged for feeding a magazine containing spaced fastening elements so that the fastening elements are successively positioned in alignment with and within the muzzle opening in said gun body for insertion into the receiving material, wherein the improvement comprises means for pivotally connecting said feed mechanism to said gun body for pivotally displacing said feed mechanism relative to said gun body between a first position in which a fastening element is aligned with and extends into the muzzle opening and displaces said driving means into the driving position with the magazine extending perpendicularly to the axis of the muzzle opening and a second position pivotally displaced outwardly from the muzzle opening with the magazine extending at an oblique angle to the axis of the muzzle opening, said feed mechanism comprises a housing forming a guideway for directing the passage of the magazine therethrough, said feed mechanism includes means actuated by the pivotal movement of said feed mechanism for controlling the movement of the magazine and disposing the fastening elements through the feed mechanism into position for alignment with said muzzle opening so that one fastening element can be positioned within the muzzle opening, said means for controlling the movement of the magazine comprises a control element mounted in said housing and displaceably positionable within said guideway, said housing has an opening alignable with the muzzle opening in said gun body when said feed mechanism is in the first position so that a fastening element positioned within the muzzle opening and any parts of the magazine associated with the fastening element located within the muzzle opening can be displaced from said feed mechanism during the insertion operation.

2. Explosive charge-driven setting gun, as set forth in claim 1, wherein said means for connecting said feed mechanism to said body comprises a pin mounted in said body spaced from said muzzle opening therein and pivotally mounting said feed mechanism at the opposite end thereof from the opening alignable with the muzzle opening in the first position of said feed mechanism, and a lever in operative engagement with said control element, said lever being pivotally connected adjacent one end to said gun body and being slidably connected to said feed mechanism at its other end and actuating said control mechanism during the pivotal movement of said feed mechanism, and said lever being slidably displaceable in said feed mechanism in the direction of the movement of the magazine therethrough.

3. Explosive charge-driven setting gun, as set forth in claim 1, wherein said driving means includes a fastening element driving piston axially displaceably positioned within the muzzle opening in said gun body and arranged to be displaced into the driving position when said feed mechanism is pivoted into its first position.

4. Explosive charge-driven setting gun, as set forth in claim 1, wherein said housing has a cutout on the opposite side thereof from the opening through which the fastening elements are inserted into the receiving material for accommodating the portion of said gun body containing the muzzle opening.

5. Explosive charge-driven setting gun for inserting fastening elements, such as bolts, nails and the like, into a receiving material, preferably a hard material, including a gun body having a muzzle opening, driving means mounted within said gun body and displaceable through said muzzle opening from a driving position rearwardly of said muzzle opening for inserting the fastening elements one at a time into the receiving material, a feed mechanism arranged for feeding a magazine containing spaced fastening elements so that the fastening elements are successively positioned in front and within the muzzle opening in said gun for insertion into the receiving material, wherein the improvement comprises means for pivotally connecting said feed mechanism to said gun body for displacing said feed mechanism relative to said gun body between a first position in which a fastening element is aligned with and extends into the muzzle opening and has displaced said driving means into the driving position with the magazine extending perpendicularly to the axis of the muzzle opening and a second position pivotally displaced outwardly from the muzzle opening with the magazine extending at an oblique angle to the axis of the muzzle opening, said feed mechanism comprises a housing forming a guideway for directing the passage of the magazine containing the fastening elements therethrough, said means for controlling the movement of the magazine comprises a control element mounted in said housing and displaceably positionable within said guideway, said housing having an opening alignable with the muzzle opening in said gun body when said feed mechanism is in the first position so that one fastening element is positioned within the muzzle opening and any parts of the magazine associated with the fastening element located within the muzzle opening can be displaced from said feed mechanism along with the fastening element during the insertion operation, in the first position said guideway in said feed mechanism extends perpendicularly to the axis of the muzzle opening and in the second position said guideway is pivotally displaced outwardly from the muzzle opening and extends at an oblique angle to the axis of the muzzle opening, said means for pivotally connecting said feed mechanism to said gun body comprises a pin mounted in said gun body and pivotally mounted in said feed mechanism, and a lever in operative engagement with said control element, said lever being pivotally connected to said gun body and to said feed mechanism and arranged to actuate said control element during the pivotal movement of said feed mechanism between the first and second position, the pivotal connection of said lever to said feed mechanism being displaceable in said feed mechanism in the direction of movement of the magazine through said guideway therein, said housing having a slot therein elongated in the direction of movement of the magazine through said guideway, and a second pin pivotally connecting said lever to said housing and said second pin extending through said slot into the interior of said housing and being connected therein to said control member and being displaceable along said slot in the elongated direction thereof so that said second pin displaces said control member in the direction of said slot in a reciprocating manner as said feed mechanism is moved between the first and second positions.

6. Explosive charge-driven setting gun, as set forth in claim 5, wherein said control element comprises a pawl mounted directly on said pin pivotally connecting said lever to said housing, said pawl extending in the direction of movement of the magazine through said housing and having a projecting portion spaced from said pin and arranged to engage a recess in the magazine.

7. Explosive charge-driven setting gun, as set forth in claim 6, wherein a spring member is positioned within said housing and is arranged to bias said pawl so that its projecting portion engages the recess in the magazine.

8. Explosive charge-driven setting gun, as set forth in claim 7, wherein said spring member is a leaf spring extending in the direction of movement of the magazine through said housing.

9. Explosive charge-driven setting gun, as set forth in claim 6, wherein locking means are associated with said housing and arranged to engage in a recess in the magazine at a position spaced from the projecting portion on said pawl in the direction of movement of the magazine through said feed mechanism.

10. Explosive charge-driven setting gun, as set forth in claim 9, wherein said locking means are located adjacent the opening in said housing through which the fastening elements are inserted into the receiving material.

11. Explosive charge-driven setting gun, as set forth in claim 10, wherein said locking means comprises at least one spring biased ball catch positioned within said housing and arranged to be releasably engaged within a recess in the magazine.

12. Explosive charge-driven setting gun, as set forth in claim 5, wherein means are associated with said feed mechanism for returning said feed mechanism from the first position into the second position.

13. Explosive charge-driven setting gun, as set forth in claim 12, wherein said means for returning said feed mechanism comprises a spring member attached to said lever and to said housing of said feed mechanism for displacing said pin pivotally mounting said lever through the slot in said housing.

14. Explosive charge-driven setting gun, as set forth in claim 13, wherein said spring member is a tension spring.