EP0467835B1 - Powder-actuated fastener driving tool - Google Patents

Abstract

The powder-actuated fastener driving tool has a barrel (11) and a breechblock (17) which are axially displaceable in a housing (1). Provided on the housing (1), on the one hand, and on the barrel (11) and on the breechblock (17), on the other hand, are mutually co-operating stops (3a, 17e) and shoulders (8b, 11e), which first limit the displacement of the barrel (11) and, after a further displacement path, the displacement of the breechblock (17) counter to the driving direction. A free space, which permits the supply, normal to the barrel axis, of propelling charges (15), in particular in magazines, thereby results between the barrel (11) and breechblock (17). <IMAGE>

Description

The invention relates to a powder-powered setting tool with a housing in which a barrel and a locking piece are arranged axially displaceably, stops on the housing on the one hand and on the locking piece on the other hand providing stops which limit the displacement movement against the setting direction, the locking piece via a compression spring acting in the setting direction on Housing is supported and the barrel has a receptacle for a propellant charge.

DE-A-16 03 843 discloses a powder-operated setting tool in which a barrel and a locking piece are displaceably mounted in a housing with the aim of reducing the recoil forces which have a disadvantageous effect on the material stress and the operator. Thanks to this displaceable arrangement of barrel and locking piece in the housing, the objective with regard to recoil forces can only be achieved with other disadvantages. These other disadvantages lie particularly in the construction. For example, it is not possible to supply propellant charges in a proven manner normal to a barrel in the barrel. To feed a propellant charge into the receptacle, the barrel is pivoted here relative to the closure piece about an eccentric bearing bolt lying parallel to the barrel axis, as a result of which the end face of the barrel with the receptacle for the propellant charge for feeding the propellant charge is exposed. This solution, which is disadvantageous in terms of handling and design effort, also does not allow magazine loading of the device with propellant charges.

Because of the aforementioned other disadvantages, the known device has not found widespread use, although it is advantageous in terms of avoiding recoil forces and, moreover, opens up possibilities for utilizing the displacement of the closure piece which is initiated by the resulting gas pressure for other functions, for example the supply of propellant charges.

The invention is therefore based on the object of providing a powder-operated setting tool which has a design which reduces the recoil forces and, moreover, allows simple feeding of also stored propellant charges normal to the barrel axis in a conventionally simple manner.

According to the invention the object is achieved in that on the one hand and on the barrel on the other hand the displacement movement of the barrel against the setting direction shoulders are provided, the distance measured between the stop and shoulder on the housing being greater than the correspondingly measured distance between the stop on the shoulder Lock piece and shoulder on the barrel in mutually supported position of the lock piece and barrel.

Due to the gas pressure that arises after the propellant charge is ignited, the barrel and locking piece in the housing move against the setting direction. Thanks to the arrangement of the stops and shoulders according to the invention, the shoulders between the barrel and the housing run into one another earlier than the stops between the closure piece and the housing. The breech block therefore moves further against the setting direction while the barrel has already come to a standstill, as a result of which a space is created between the barrel and breech block and the receptacle for the propellant charge is exposed. The free space created in this way allows propellant charges to be supplied for inclusion normal to the barrel axis, both individually and in a magazine, for example in a carrier strip known per se. For this purpose, the difference between the distance according to the invention is selected to be greater than the length of the propellant charge and any part of a carrier strip that projects beyond the propellant charge in the longitudinal direction.

A carrier strip of the known type can be held in a guide channel on the closure piece, as a result of which, when the closure piece is displaced relative to the barrel, a used propellant charge is drawn out of the receptacle.

A transport rocker which is in engagement with a carrier strip containing propellant charges is preferably arranged on the housing. After a propellant charge has been ignited, the carrier strip with the closure piece moves against the setting direction. The carrier strip is displaced in relation to the rocker and moved further by one transport step, for example when it is moved back in the setting direction. When the transport strip is moved against the setting direction, the transport rocker dodges to follow up for the next transport step.

The transport rocker is expediently designed as a swivel lever which is rotatably mounted in the housing and has a control cam for the carrier strip. With the end facing away from the control curve, the swivel lever can be rotatably mounted on the housing about an axis running normally to the longitudinal extent of the swivel lever and can be held against the carrier strip with the control curve by spring force. The control curve can interact with recesses in the edge zone of the carrier strip, for example in such a way that when the carrier strip is displaced, the pivot lever with the control curve is deflected from a recess counter to the setting direction and engages in a respective next recess when displaced in the opposite direction. The control curve can be formed by a strip-shaped elevation which, depending on the cross section of the recesses on the carrier strip, is profiled in a manner known per se.

The supply of propellant charges normal to the barrel axis is advantageously facilitated in that an engaging locking device is provided between the housing and the closure piece when the stops of the housing and closure piece come up against the displacement of the closure piece in the setting direction. The locking device holds the locking piece in the position facing away from the setting direction until disengagement, as a result of which the space created after the barrel is stopped by further displacement of the locking piece against the setting direction is maintained until the locking device is disengaged again.

The locking device is preferably mounted on the housing and has a support shoulder for the closure piece. The arrangement of the locking device on the housing is advantageous in terms of movement and function, in that the locking device only has to perform an engagement and disengagement movement relative to the housing to be regarded as a stationary part. For example, the locking device can be designed as a one-armed pivot lever. The support shoulder can grip the closure piece in the position facing away from the setting direction.

A spring element serving to engage the locking device is advantageously provided. The spring element causes the locking device to engage automatically as soon as the closure piece reaches the effective area of the support shoulder on the locking device.

An actuating member serving to disengage the locking device is expediently provided. The actuating member is advantageously designed as a control contour which interacts with the barrel when the barrel is displaced in the setting direction. The barrel carries, for example, a control cam which engages towards the end of the displacement of the barrel into the setting direction end position for disengaging the locking device on the control contour. This creates a further increase in the free space between the breech piece and barrel. This is particularly advantageous if the displacement of the closure piece in the setting direction after the locking device has been disengaged is used to transport a carrier strip which extends normally to the barrel axis.

The disengagement of the locking device by moving the barrel in the setting direction is preferably carried out automatically by a spring which displaces the barrel in the setting direction and is supported on the housing.

Fig. 1

ein pulverkraftbetriebenes Setzgerät im Längsschnitt, in Ruhestellung;

Fig. 2

das Setzgerät nach Fig. 1 in zündbereiter Anpressstellung;

Fig. 3

das Setzgerät nach Fig. 1 beim Setzvorgang, nach Zünden einer Treibladung;

Fig. 4

das Setzgerät nach Fig. 1 bei Rückführung des Laufes in Setzrichtung;

Fig. 5

einen Schnitt durch das Setzgerät, gemäss Schnittverlauf V-V in Fig. 1, in vergrösserter Darstellung;

Fig. 6

einen Schnitt durch das Setzgerät, gemäss Schnittverlauf VI-VI in Fig. 5;

Fig. 7

eine vergrösserte perspektivische Darstellung der Transportwippe;

Fig. 8

einen Schnitt durch das Setzgerät, gemäss Schnittverlauf VIII-VIII in Fig. 4, in vergrösserter Darstellung.

The invention is explained in more detail below with reference to drawings which show an exemplary embodiment. Show it:

Fig. 1

a powder-powered setting tool in longitudinal section, in the rest position;

Fig. 2

1 in the ready-to-ignite pressing position;

Fig. 3

the setting tool of Figure 1 during the setting process, after igniting a propellant charge.

Fig. 4

the setting tool of Figure 1 when returning the barrel in the setting direction.

Fig. 5

a section through the setting tool, according to section VV in Fig. 1, in an enlarged view;

Fig. 6

a section through the setting tool, according to section VI-VI in Fig. 5;

Fig. 7

an enlarged perspective view of the transport rocker;

Fig. 8

a section through the setting tool, according to section line VIII-VIII in Fig. 4, in an enlarged view.

The setting tool has a housing 1 with a plastic shell 2 and a tubular guide body 3 inserted therein. The plastic shell 2 carries a laterally protruding handle 2a, in which a hint trigger 4 of a trigger device, not shown, is known. On the setting direction side, a protective cap 5 sits on the plastic shell 2 and is fixed by a retaining ring 6.

In the setting direction, an opening part 7 protrudes from the protective cap 5. The opening part 7 is seated at the rear in a guide tube 8 and is releasably held on the guide tube 8 by a clamping nut 9. Mouth part 7, guide tube 8 and clamping nut 9 are displaceable with respect to the housing 1.

The guide tube 8 is surrounded by a barrel 11 which extends beyond the guide tube 8 against the setting direction. By means of a spring 12, which is shouldered against the setting direction on a support shoulder 2b of the plastic shell 2 and in the setting direction on a support plate 11a of the barrel 11, the barrel 11 according to FIG. 1 is pressed against a stop ring 13 supported on the housing with the support plate 11a . With the end face pointing in the setting direction, the barrel 11 also drives the mouth part 7 and the guide tube 8 in the setting direction via the clamping nut 9. In the bore 8a of the guide tube 8 and in the barrel bore 11b, a driving piston 14 is displaceably mounted with an enlarged ring section 14a or an enlarged head 14b. A shaft 14c pointing in the setting direction and having a smaller diameter than the ring section 14a and the head 14b passes through an orifice bore 7a in the orifice part 7. Contrary to the setting direction, a channel 11c adjoins the barrel bore 11b, into which a receptacle 11d for a propellant charge 15, which, for example, is contained in a carrier strip 16, opens out.

Behind the barrel 11, a closure piece 17 is slidably mounted in the guide body 3 of the housing 1. In the closure piece 17, on the setting direction side, the carrier strip 16 with propellant charges 15 is seated in a guide channel 17a. The carrier strip 16 can be displaced with the propellant charges 15 along the guide channel 17a normal to the barrel axis. The closure piece 17 is driven in the setting direction by a compression spring 18 and is in the rest position of the setting device shown in FIG. 1 with a back 17b of a window-like recess 17c on a bearing shell 19a of a pivotable locking device 19. The bearing shell 19a is supported on a bearing pin 21 which is fixed in the housing 1.

The locking device 19 is designed as a one-armed pivot lever and has a support lug 19b directed clockwise of the pivoting movement, with which the locking device 19 is supported on the peripheral surface of the closure piece 17 when the setting tool is in the rest position. The support lug 19b also forms a support shoulder 19c that is exposed against the setting direction. The free end of the locking device 19 is widened like a head and has an actuating member 19d in the form of a control contour. A spring element 22, which is held by the bearing pin 21, drives the locking device 19 in a clockwise direction and thereby holds the support lug 19b against the closure piece 17.

An ignition pin 23 is slidably mounted in the closure piece 17. This has a laterally projecting driving cam 23a. The driving cam 23a projects into the axial projection of a driving bolt 24 which projects into the locking piece 17 and projects from the barrel 11 in the opposite direction to the setting direction. An ignition tip 23b projects in the setting direction and engages in a passage opening 17d in the locking piece 17. A tension spring 25, which is located on a support disk 26 shouldered in the closure piece 17, drives the ignition pin 23 in the setting direction. On the rear, a retraction spring 27 is seated on the firing pin 23, which is supported on the firing pin 23 via a disk 28 to the rear and via a support ring 29 to the front.

In order to achieve the ignition-ready pressing position shown in FIG. 2, the setting tool with the mouth part 7 is pressed against the underground U. As a result, the mouth part 7 moves against the setting direction and on the one hand takes the guide tube 8 and on the other hand the barrel 11 against the setting direction. The driving pin 24 engages the driving cam 23a and thus displaces the firing pin 23 also against the force of the tension spring 25. The barrel 11 then hits the closure piece 17. By moving the barrel 11 against the setting direction, the spring 12 is also tensioned.

As can be seen from the comparison of FIGS. 1 and 2, when the barrel 11 is moved into the ignition-ready pressing position, a control cam 31 protruding laterally from the barrel 11 passes the end of the locking device 19 having the actuating member 19d.

Subsequent release of the firing pin 23, for example by turning the firing pin 23 so that the driving cam 23a comes out of the axial projection of the driving pin 24, ignites the propellant charge 15 which is overlapped by the receptacle 11d. The resulting gas pressure acts on the driving piston 14. This is accelerated to drive a fastening element 32 into the underground U in the setting direction, as shown in FIG. 3. However, the gas pressure also generates forces acting against the setting direction on the barrel 11 and on the closure piece 17, so that these parts move relative to the housing 1 against the setting direction. The barrel 11 moves in the process until a shoulder 11e strikes a shoulder 8b which is stationary with respect to the housing 1 (FIG. 3). The closure piece 17 continues counter to the setting direction and pulls the used propellant charge 15 out of the receptacle 11d. The closure piece 17, with the rear end face serving as a stop 17e, strikes the inner end face of the guide body 3, which acts as a stop 3a on the housing side. Shortly before this stop position of the closure piece 17 is reached, its front end face 17f passes behind the support shoulder 19c, as a result of which the locking device 19 with the support lug 19b can pivot in front of the closure piece 17.

The spring element 22 automatically swivels in, as shown in FIG. 3.

Immediately after the fastening element 32 has been driven in, the driving piston 14 is driven into the rest position against the setting direction by supplying part of the driving gases into the bore 8a of the guide tube 8. The space behind the head 14b is vented via a channel 11f (FIG. 3). At the same time, the tensioned compression spring 18 drives the closure piece 17 with the front end face 17f against the pivoted-in support shoulder 19c, as shown in FIG. 4. The closure piece 17 is prevented from moving in the setting direction until the locking device 19 is pivoted counterclockwise.

After the fastening element 32 has been driven in, the setting tool is lifted from the underground U, whereupon the barrel 11 is displaced in the setting direction by the spring 12 and the mouth part 7 and the guide tube 8 are also displaced. A corresponding free space is formed between the barrel 11 and the closure piece 17 for feeding a new propellant charge 15 normal to the barrel axis. After this clearance has been obtained, the control cam 31 runs on the actuating member 19d and pivots the locking device 19 counterclockwise while moving the barrel 11 further in the setting direction. The support shoulder 19c subsequently releases the front end face 17f, so that the closure piece 17 can be driven by the compression spring 18 into the rest position shown in FIG. 1. The barrel 11 also assumes the rest position shown in FIG. 1, the control cam 31 having passed over the front end of the locking device 19 in the setting direction.

5 to 8 in particular, the carrier strip 16 has rectangular recesses 16a in the edge zone. A control cam 33a, which is arranged in the form of a strip-shaped elevation on a transport rocker 33, engages in the recesses 16a. As shown in FIGS. 6 and 7, the control curve 33a has a substantially sawtooth shape in cross section, its steep flank 33b in the transport direction and its less steep flank 33c oppose it the direction of transport. The transport rocker 33 is designed as a pivot lever and is rotatably supported on the guide body 3 by a bolt 34. A compression spring 35 supported on the guide body 3 drives the transport rocker 33 with the control cam 33a against the edge zone of the carrier strip 16. For lateral guidance of the transport rocker 33, this has a guide groove 33d into which the guide body 3 protrudes (FIG. 6). A latching device with a ball 36 and a cylinder spring 37 holds the carrier strip 16 in position after the respective transport step, with the ball 36 engaging in one of the recesses 16a, as shown in FIG. 6.

In the rest position of the device, the control cam 33a engages with the section on the setting direction in one of the recesses 16a of the carrier strip 16, as can be seen in FIGS. 5 to 7. After igniting the propellant charge 15 located in the effective area of the firing pin 23, the closing piece 17 is, as explained above, displaced by the gas pressure against the setting direction and takes the carrier strip 16 with the propellant charges 15 with it. This displacement movement leads to a deflection of the control cam 33a out of the recess 16a in that the side wall of the recess 16a pushes the control cam 33a outward against the force of the compression spring 35 via the less steep flank 33c. The carrier strip 16 then passes with a next recess 16a over the section of the control cam 33a facing away from the setting direction, so that the control cam 33a is pushed into this next recess 16a by the compression spring 35 (FIG. 8).

When the setting tool is lifted from the underground U, the closure piece 17 moves in the setting direction, as a result of which the steep flank 33b, when engaged in the recess 16a, causes the carrier strip 16 to be moved by one transport step. The ball 36 of the latching device initially releases the carrier strip 16 in order to snap into the next recess 16a after the transport step has taken place. The ignited Propellant charge 15 is transported away in this way and a propellant charge 15 that is not ignited reaches the effective area of the firing pin 23.

Since the next propellant charge 15 is transported only after a propellant charge 15 has been ignited beforehand, it is ensured that no unignited propellant charge 15 is transported further and can thus get out of the setting tool. For the exit of the carrier strip 16 with ignited propellant charges 15, passage openings 2c or 3b are provided in the plastic shell 2 and in the guide body 3. The carrier strip 16 with the propellant charges 15 is fed to the guide channel 17a via a guide rail 38 connected to the closure piece 17. From the outside, the guide channel 17a and the carrier strip 16 are covered by a protective shield 39 fixed to the housing 1.

Claims (9)

1. Explosively actuated setting tool comprising a housing (1) with an axially displaceable barrel (11) and a sealing element (17 arranged therein, in which respect on the housing (1) on the one side and on the sealing element (17) on the other side are provided stops (3a, 17e) which limit the displacement movement of the sealing element (17) against the setting direction, the sealing element (17) is supported against the housing (1) via a pressure spring (10) acting in the setting direction, and the barrel (11) comprises a receptacle (11d) for an explosive charge (15), characterised in that on the housing (1) on the one side and on the barrel (11) on the other side are provided shoulders (8b, 11e) which limit the displacement movement of the barrel (11) against the setting direction, wherein the distance at the housing (1) between stop (3a) and shoulder (8b), as measured along the displacement movement, is greater than the respectively measured distance between stop (17e) at the sealing element (17) and shoulder (11e) at the barrel (11) in a mutually supporting position of sealing element (17) and barrel (11).
2. Setting tool according to claim 1, characterised in that on the housing (1) is arranged a transport rocker (33) which engages a carrier strip (16) holding explosive charges (15).
3. Setting tool according to claim 2, characterised in that the transport rocker (33) is arranged as a pivot lever, which is rotatably mounted in the housing (1) and which comprises a control curve (33a) for the carrier strip (16).
4. Setting tool according to one of claims 1 to 3, characterised in that between the housing (1) and the sealing element (17) is provided an engageable blocking device (19) which, on contact of the stops (3a, 17e) of the housing (1) and the sealing element (17), opposes displacement of the sealing element (17) in the setting direction.
5. Setting tool according to claim 4 characterised in that the blocking device (19) is mounted on the housing (1) and comprises a support shoulder (19c) for the sealing element (17).
6. Setting tool according to claim 4 or 5, characterised in that spring element (22) is provided to serve the engagement of the blocking device (19).
7. Setting tool according to one of claims 4 to 6, characterised in that an operating element (19d) is provided to serve the disengagement of the blocking device (19).
8. Setting tool according to claim 7, characterised in that the operating element (19d) is arranged as a control contour which coacts with the barrel (11) during a displacement of the barrel (11) in the setting direction.
9. Setting tool according to claim 0, characterised in that spring (12) is provided, which displaces the barrel (11) in the setting direction and which is supported against the housing (1).

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