WO2002034450A1

WO2002034450A1 - Pistol-handle for hand-held tool, such as welding-gun

Info

Publication number: WO2002034450A1
Application number: PCT/SE2001/002227
Authority: WO
Inventors: Hans Johansson
Original assignee: Johansson Hans Arne Valentin
Priority date: 2000-10-16
Filing date: 2001-10-15
Publication date: 2002-05-02
Also published as: SE0003717L; SE516101C2; AU2001296122A1; SE0003717D0

Abstract

A pistol grip for a hand tool consisting partly of a working part (1) with an electrical circuit, and partly of a handle (3), which is attached to the working part (1) by means of a ball joint (4). The ball joint is provided with a hollow ball (5), which is mounted movably in a socket (6) and can be locked in the desired position by means of a tightening device (8) which, for the purpose of locking the ball joint, is arranged so as to act one a tapered element (9) extending into the ball (5), the tapered element (9) pressing the periphery of the ball against the inner wall of the socket (6). The handle is provided with a trigger (10), which actuates a flexible rod (11) which is supported and is free to move, partly within a passage (12) exiting at the tip of the tapered element, and partly within a passage (13) exiting at an attachment (14) for the working part (1), the rod (11) being arranged at the attachment point (14) to bridge two poles in the electrical circuit in the working part (1) in order to activate same.

Description

PISTOL-HANDLE FOR HAND-HELD TOOL, SUCH AS WELDING-GUN

Technical application

The present invention relates to a pistol grip for a hand tool, such as a welding gun, which pistol grip consists of a working part incorporating an electrical circuit, and a handle, which is connected to the working part by means of a ball joint, which incorporates a hollow ball, which is arranged to move freely within a socket and which is provided with slots extending through the wall of the ball.

Background to the invention

A pistol grip for a welding gun is known from US-A-3 109 916 and, compared with a conventional pistol grip without a ball joint between the handle and the electrode holder, offers ergonomic advantages in that the ball joint enables the user to assume a comfortable working posture at all times, while also facilitating work in confined spaces by enabling the user to adjust the handle to the most favourable setting in every instance.

A disadvantage of the known solution is that the welding electrode cannot be activated from the handle and that the Gabling running through the handle to the said device makes it difficult to adapt the handle to electrode holders other than that described in the US document.

Purpose of invention

Against this background, the purpose of the invention is to achieve a universally usable pistol grip for a hand tool, such as a welding gun, which pistol grip, by virtue of the handle which comprises part of it, is designed to enable an electrical circuit in the working part to be activated, and which pistol grip shall be universally usable with a large number of different hand tools, including welding guns. Summary of invention

This purpose is achieved in accordance with the invention with the aid of a pistol grip as described in the introduction, which pistol grip is characterised by the fact that the ball joint can be locked in the desired position by means of a tightening device which, in for the purpose of locking the ball joint, is arranged to act on a tapered element extending into the ball, the tapered element pressing the periphery of the ball against the inner wall of the socket, the handle being provided with a trigger, which acts on a flexible pushrod, which is supported and is free to move, partly within a passage running through the tapered element and exiting at the upper end of the tapered element, and partly within a passage running through the socket and exiting at an attachment for the working part, which pushrod is, at the attachment end, by means of two electrically conducting contact devices, arranged to bridge two poles of the electrical circuit in the working part in order to activate same. The solution in accordance with the invention makes it particularly easy to attach the pistol grip to different hand tools, such a welding gun, incorporating an electrical circuit and to activate the said circuit from the handle, the ball joint enabling the working part to adjusted to many different and, from an ergonomic viewpoint, favourable settings relative to the handle. The tightening device should preferably be a locking screw extending a distance along the handle from its (the handle's) end. This enables the handle grip to be located very close to the ball joint, which is ergonomically advantageous. Furthermore, an attachment should preferably be provided between the ball joint and the working part, the attachment consisting of a key element and a keyway element in which the key element can be locked. This arrangement enables the handle and working part to be separated which, in some cases, may be necessary when working in confined spaces and which may be practical when transporting the pistol grip with the tool attached to it.

In the latter solution, the key element should preferably be attached to the socket and should incorporate the aforementioned poles, while the keyway element should preferably be attached to the working part and should incorporate the contacts designed to be connected electrically to the poles when the key element is pushed into the keyway element. This solution, which is comparable to that used in a photographic flash unit, guarantees in a uniquely simple manner that electrical contact is achieved and that incorrect polarity is avoided. Finally, the contacts may conveniently be connected to electric leads connected in turn to the electrical circuit in the working part. The advantage of this solution is that it enables the handle to be connected to different working parts, to which electrical contact can be made by means of the said leads.

Brief description of drawings

Fig. 1 shows a welding gun (working part) and pistol grip.

Fig. 2a shows a pistol grip in cross-section connected to a working part.

Fig. 2b shows a pistol grip in cross-section connected to a working part.

Fig. 3 shows a ball socket with a key element and electrical poles.

Fig. 4 shows a tapered element.

Fig. 5 shows the attachment device.

Description of an embodiment

The pistol grip described is designed for attachment to a wire welding gun by means of a few simple manual actions.

The pistol grip consists of a handle (3) which is attached to a quick-release attachment (14) by means of a ball joint (4). The ball joint (4), which consists of a hollow ball (5) provided with slots (7) and a socket (6), can be locked in an optional position within about 30 degrees of the vertical axis of the handle by tightening a locking screw (8) to apply a tapered element (9). The tapered element (9) presses the periphery of the ball (5) against the inner wall of the socket (6).

The tapered element (9) is provided with a diametral cavity (17) in which the control device bracket (18) is seated. A flexible rod (1 1), one end of which is retained in a recess in the lever arm (19) of the control device by a spring (20), passes through a hole (12) located on the centre line of the tapered element and further through the ball joint (4 ) to the attachment (14). The lever arm (19) can be lifted by the wedge (25), which can be actuated by the trigger (10) by means of a rod (26), which is fixed in the wedge (25) and which also serves as a guide since the rod (26) passes through a hole (27) in the bracket (18). The rod (26) is provided with a head at the end in contact with the trigger (10) and is retained in contact with the trigger (10) by the spring (28). The pistol grip (3) is attached to the welding gun (1) by a finite keyway (21) provided with two parallel metal sleeves (22) located at the furthermost end of the keyway extension. The sleeves (22) and the ordinary control device of the welding gun (1) are connected by electric leads (29). The attachment on the pistol grip consists of a key element (23) whose shape corresponds to that of the keyway (21), as well as two electrically conducting pins (16) attached to the key element (23) and arranged parallel to its longitudinal axis, which pins are designed to enter the sleeves (22) and to form a contact device in combination with them. The pins (16) also comprise two parts of the electrical switch whose third part consists of an electrically conducting contact device

(15), the diameter of which is bigger than the distance between the pins (16) at the upper end of the rod (11) connecting the control device of the pistol grip (3) to the switch. The attachment (14) comprises a single part with the ball joint socket (6) (Fig.

3).

Although the invention has been described only in the context of a welding gun pistol grip, it is clear that the same solution may also be applied to other pistol grips in which two poles of an electrical circuit must be bridged and/or the pistol grip must be adjustable.

Claims

PATENT CLAIMS

1. Pistol grip for a hand tool, such as a welding gun, which pistol grip consists of a working part incorporating an electrical circuit, and a handle (3), which is attached to the working part (1) by means of a ball joint (4), which is provided with a hollow ball (5), which is arranged to move freely within a socket (6) and which is provided with slots (7) extending through the wall of the ball, characterised in that the ball joint (4) can be locked in the desired position by means of a tightening device (8) which, for the purpose of locking the ball joint, is arranged so as to act on a tapered element (9) extending into the ball (5), the tapered element (9) pressing the periphery of the ball (5) against the inner wall of the socket (6), the handle (3) being provided with a trigger (10), which actuates a flexible rod (11) supported movably, partly within a passage (12) extending through and exiting at the tip of the tapered element, and partly within a passage (13) extending through the socket (6) and exiting at an attachment (14) for the working part (1), the rod (11) being arranged at the attachment point (14) to bridge two poles (16) in the electrical circuit in the working part (1) by means of an electrically conducting contact device (15), thereby activating the working part.

2. Pistol grip as per patent claim 1, characterised in that the tightening device is a locking screw (8), which extends a distance along the handle (3).

3. Pistol grip as per patent claim 1 or 2, characterised in that an attachment (14) is arranged between the ball joint and the working part, which attachment consists of a key element (23) and a matching slotted element (21), which key element (23) is lockable.

4. Pistol grip as per patent claim 3, characterised in that the key element (23) is attached to the socket (6) and that it incorporates the aforementioned poles (16), also that the slotted element (21) is connected to the working part (1) and is provided with contacts (22) arranged so as to come into electrical contact with the poles (16) when the key element (23) is pushed into the slotted element.

5. Pistol grip as per patent claim 4, characterised in that the contacts (22) are connected electrically to the electrical circuit of the working part by electric leads (29).