GB2425087A

GB2425087A - Motor-driven staple gun

Info

Publication number: GB2425087A
Application number: GB0607197A
Authority: GB
Inventors: Ernst Kraenzler; Joao Jorge Bergner; Sieghard Amann; Erol Ergin; Michael Haeussler
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2005-04-11
Filing date: 2006-04-10
Publication date: 2006-10-18
Anticipated expiration: 2026-04-10
Also published as: GB0607197D0; GB2425087B; DE102005016454A1

Abstract

The gun 10 for driving staples 56 or nails into a work piece includes a ram 46 guided in a staple gun lug 38. The staples or nails can be arranged in blocks in a magazine shaft 26 and are guided transversely to the driving-in direction into the movement path of the ram. The lug may be separate from the magazine shaft and is supported and guided to move parallel to its longitudinal axis between two defined end positions in a straight line relative to the magazine shaft. On its movement path between the two end positions it is associated with a limit switch 44 to interrupt or close an electrical circuit to activate a motor drive.

Description

Hand-held machine tool for driving in staples and/or nails This invention

starts from a hand-held machine tool according to the pre-characterizing clause of Claim 1.

Most commonly sold staple guns have a safety device which prevents an unwanted shot being triggered. Such triggering can result in staples and/or nails flying about out of control - with corresponding danger of injury for the operator and persons around the operator. The safety device can be activated and deactivated by the staple gun lug which guides the ram for driving in the staples and/or nails being linked to switching means, so that it releases a lockout when it is placed on the workpiece and moved by a few millimetres against the direction of placing. The movement of the staple gun lug takes place in the form of a swivelling movement together with a magazine, which is joined rigidly to the staple gun lug, for staples or nails.

The structural unit of staple gun lug and magazine is - similarly to the case of office staplers - supported so that it can be moved relative to the housing around a swivelling axis which is arranged near the rear end of the magazine. Only in the moved position of the staple gun lug, a switch which is arranged near the swivelling axis is opened, and thus the lockout on triggering the ram is cancelled.

A bearing arrangement of the staple gun lug with the magazine without any play is only achievable at relatively high cost. Also, when the staple gun lug is placed on a workpiece to activate the safety switch, it moves on a circuit with the radius of the distance of the staple gun lug from the swivelling axis. In this case the guidance of V. the staple gun lug, because of the changing swivelling deflection, is subject to high material stress.

Advantages of the invention The hand-held machine tool with the features of Claim 1 has the advantage that the shot safety device only is integrated into the staple gun lug, separate from the magazine shaft and thus specially simple.

Because there is no play in the cutter guidance in the staple gun lug, one wrong function, that is the production of double staples or nails, can be excluded.

Because the staple gun lug is narrowly guided in its longitudinal movement in the plastic housing on opposite sides, and is reset by means of two compression springs, play is greatly reduced.

Support of magazine is done very efficiently by stop lever and stop pin.

Because the staple gun lug is supported and guided so that it can be moved parallel to its longitudinal axis between two defined end positions and in a straight line relative to the magazine, and on its movement path between these end positions is associated with a contact switch so that it can be activated, the magazine shaft can be arranged rigidly and independently of the staple gun lug, so that the arrangement becomes simpler and more robust.

Because the magazine shaft is arranged rigidly in the housing, the staples are more precisely guided.

Because a lateral window is arranged in the magazine shaft and leads to the staple gun lug, the staples/nails can be supported laterally on the staple gun lug and reduce their play.

Because the staple gun lug has a lateral dog, with which it reaches and activates the activating part of the contact switch, a shot lockout is specially easy to implement.

Because the magazine is guided so that it can move longitudinally in the rigid shaft and because the staple gun lug is movably arranged transversely to it and to its longitudinal axis the system has only a minimum of play.

At the triggering lifting movement to activate the safety switch, the staple gun lug and ram move on a straight movement path.

Drawings Below, the invention is explained in more detail on the basis of an embodiment, with associated drawings.

Fig. 1 shows a side view of an electrical staple gun, partly cut away, with locked shot safety device; Fig. 2 shows a section of the staple gun according to Fig. 1, with opened shot safety device; Fig. 3 shows the section according to Fig. 2 rotated to the right; and Fig. 4 shows a view of the staple gun from below.

Description of the embodiment

Fig. 1 shows an electrical staple gun 10 with a housing 12, which forms a bow handle 14 on its top side. Under the bow handle 14 there is a switch button 16. By means of this switch button 16, an electrical circuit of the electrical drive 17, which can be connected via a mains cable 18 to a mains power supply, is opened or closed.

A lower housing part 22 below the bow handle 14 forms a long magazine shaft 26 which is meant to be opened to the rear, to receive a set of staples 26 (Fig. 3) or u-shaped staples 56 which are joined to each other in a block, and may be mounted in or on a magazine 24. The staples 56 are elastically prestressed and pushed forwards horizontally by means of a stop lever 28, so that each time, the furthest forward of the staples 56 is positioned into the movement path of a ram 46 to receive its impact pulse for further movement in the driving-in direction. The stop lever 28 catches and is supported on a stop pin 30, so that the staples 56 or magazine 24 can be pulled backwards out of the housing 12 only after the stop lever 28 is pushed down.

On the top side of the housing part 22, there is an adjustment wheel 20, to adjust the driving-in impact force, which becomes effective on the staple 56, of the ram 46.

A staple gun lug 38 on the front 34 of the housing 12 forms the straight guide for the staples 56 in the driving-in direction, and is in the form of a u-shaped groove 47 in thick-walled sheet metal. The staple 56 which is ready to be shot lies in the groove 47 in such a way that its U legs 57 are positioned parallel to the groove side walls 41 and supported on the groove base 61, so that it can leave the groove 47 with the U legs 57 in front, and can penetrate a The staple gun lug 38 is guided in the housing 12 by means of a straight guide 40, so that it can move in a straight line. The slot-like straight guide 40 is formed by the front face (which is perpendicular to the longitudinal axis of the magazine shaft 26) of the magazine shaft 26 and a sinusoidally wavy leaf spring 50. On the underside 32 of the housing 12, the front face of the magazine shaft 26 forms a stop lug 36, which runs parallel to the staple gun lug 38, and beyond which the staple gun lug 38, in the normal case when the staple gun 10 is activated, is not pushed further into the interior of the housing.

Inside the housing 12, the staple gun lug 38 carries a trip cam 42 at the front. This is associated with a probe 43 of a limit switch 44, which it reaches at the end of the movement path of the staple gun lug 38 and thus activates.

The movement path of the staple gun lug 38 is limited by at least one rib, which acts as an internal limit stop 54, in the housing 12. In this way, the limit switch 44 is also protected from mechanical damage caused by the staple gun lug 38 or trip cam 42 being pushed too far.

The ram 46 is activated by means of an electrical drive 17 when it is triggered. The electrical circuit of the staple gun 10 is interrupted by the limit switch 44 when the staple gun lug 38 is down in the springprestressed position, and thus triggering of a shot is excluded.

By placing the staple gun lug 38 on a fixed workpiece (not shown), it is pressed in by a travel distance 60 as shown in Fig. 2, or moved axially against at least one resetting spring 48 until the stop lug 36 on the underside of the housing 12 is on the workpiece and the staple gun lug 38 cannot be moved any further. The electrical circuit of the electrical drive is then closed by the limit switch 44 and the shot can be triggered.

Resetting springs ensure that the staple gun lug 38 is reset into the initial position and thus that the electrical circuit is opened.

Ram guidance without play is ensured by the leaf spring 50, which touches the front of the staple gun lug 38. By spring-prestressed support of the front of the magazine 24 on the back of the staple gun lug 38, its play is minimised, so that the ram 46 cannot deviate from its guide groove 47.

The rear view of the staple gun lug 38, shown in Fig. 3, shows its form as stamped sheet metal, with guide groove 47 with groove side walls 59 and groove base 61. It can also be seen that the staple gun lug 38 is supported and spring- prestressed upward against two internal limit stops 54 by means of two resetting springs 48, and thus allows it to be lifted to activate the limit switch 44.

It can also be seen that the staple gun lug 38 can be moved relative to the ram 46 when it carries out its travel.

Fig. 4 shows the view of the staple gun 10 from below, looking at the underside 32, which is used to support the staple gun 10 on a workpiece to be processed.

Switching through the electrical circuit when the trip cam 42 of the staple gun lug 38 is placed on the probe 44 of the limit switch 44.

The movement path of the ram 46 and a u-shaped staple 56 is determined by the guide groove 47 with its groove base 43 and groove side walls 41, and agrees with the driving-in direction of the staple 56.

Claims

Claims 1. Motor-driven staple gun (10) for driving staples (56), nails and

similar into a workpiece by means of a ram (46), wherein the ram (46) is guided in a staple gun lug (38), and the staples (56) or nails, which can be arranged, in particular, in blocks in a magazine shaft (26), can be guided transversely to the driving-in direction into the movement path of the ram (46), in particular in the case of a staple gun lug (38) which is separate from the magazine shaft (26), characterized in that the staple gun lug (38) is supported and guided so that it can be moved parallel to its longitudinal axis between two defined end positions and in a straight line relative to the magazine shaft (26), and on its movement path between these end positions is associated with a limit switch (44) to interrupt/close an electrical circuit to activate the motor drive so that it can be activated.
2. Staple gun according to Claim 1, characterized in that the magazine shaft (26) is independent of the staple gun lug (38), in particular separate from it, and arranged rigidly in the housing (12)
3. Staple gun according to Claim 1 or 2, characterized in that the magazine shaft (26) has a window to the staple gun lug (38) for staples (56) or nails, the longitudinal axis of the magazine shaft (26) passing transversely through the staple gun lug (38).
4. Staple gun according to Claim 3, characterized in that the staple gun lug (38) has a trip cam (42), with which it acts to activate the limit switch (44)
5. Staple gun according to Claim 1, characterized in that a magazine (24) is guided so that it can move longitudinally in the rigid magazine shaft (26), the staple gun lug (38) being arranged so that it can move in a straight line transversely to the magazine shaft (26)
6. A staple gun substantially as herein described with reference to the accompanying drawings.