Electric hand tool

The tool has, in a casing (2), electrically operated components and a housing (4) to accommodate a battery (3) that powers the components, with detachable elements (10, 24) of securing the battery in its housing in a position of mechanical locking and electrical connection to the components and in a position in which it is mechanically retained in its housing but electrically disconnected. The securing element (24) is designed to retrain the battery (3) in the electrically disconnected position only by friction (24, 31), thus avoiding any wrong move.

FIELD OF THE INVENTION

The invention relates to a manually operated apparatus or tool such as, for example, a drilling or holing apparatus, of the power hammer type, or a fastening apparatus of the sealing apparatus type having a piston propelled by gas.

BACKGROUND OF THE INVENTION

Such apparatuses may have operating and control electronics, an igniter plug, a fan, an electric motor or other components requiring an electrical power supply. Being manually operated and self-contained, they also comprise a power supply battery.

Once the battery has been mounted on the outside of the collection of the other elements of the apparatus, with the disadvantage, in particular, of exposing them to knocks which may damage them, a proposal was made to arrange them in an accommodating housing inside the apparatus, formed, for example, in a leg connected to the central body of the apparatus and running parallel to its operating handle.

As a safety measure, it was then proposed for the battery to be fixed in the apparatus by means of a double-action locking device, it being possible first of all for the battery to be locked mechanically and electrically and then disconnected electrically from the remainder of the apparatus while remaining mechanically connected thereto so as to prevent the operator from letting it fall out through not paying sufficient attention. Document EP 1 205 282 teaches such a device comprising, on the apparatus, a double trigger for actuating two retaining fingers designed to collaborate in succession with a single retaining catch formed on the battery. However, such an arrangement does not set aside the risk of the operator inadvertently actuating the double trigger twice and thus completely releasing the battery from the apparatus.

SUMMARY OF THE INVENTION

The present invention is aimed at reducing such a risk.

To this end, the invention relates first of all to an electric hand tool comprising, in a casing, electrically operated components and a housing to accommodate a battery that powers the said components, with detachable means of securing the battery in its housing in a position of mechanical locking and electrical connection to the said components and in a position in which it is mechanically retained in its housing but electrically disconnected, characterized in that the securing means are designed to retain the battery in the electrically disconnected position only by friction.

By virtue of the invention, in order to completely release the battery from the tool, an operator is obliged to take it in his hand and remove it from its housing, overcoming the friction forces which retain it, thus avoiding any risk of an unintentional wrong move.

In the preferred embodiment of the tool of the invention, the battery-accommodating housing is designed to accommodate therein a battery by sliding, and the battery securing means comprise an electrical locking finger and a mechanical retaining finger both mounted so that they can move, in a direction roughly orthogonal to the direction in which the battery slides, between a lock and a retaining position, respectively, and a retracted position.

As a preference, the locking and retaining fingers are mounted so that they can be moved into the retracted position against the action of elastic return means.

Advantageously, the locking finger is secured to a rod mounted to slide into the retracted position against the action of a return spring under the action of an actuating trigger and the retaining finger is secured to a pivoting elastic leaf.

Advantageously too, the locking finger and the retaining finger are mounted to be moved into the retracted position, one in each of two opposite directions.

The invention also relates to a battery for powering electrically operated components for the electric hand tool of the invention, characterized in that it comprises a mechanical and electrical locking catch and mechanical retaining ramp means.

In the preferred embodiment of the battery, the locking catch is formed by an undercut internal shoulder and the ramp means comprise a retaining boss with an entry ramp and an opposite retaining ramp advantageously formed near the entry end of the battery, via which end it is introduced into its accommodating housing in the tool, the locking catch and the retaining boss being formed respectively on two opposite sides of the battery.

DETAILED DESCRIPTION OF THE INVENTION

The tool depicted in the FIGURE in this instance is a hammer drill intended to strike a drill bit, also driven in terms of rotation in support material, via a piston propelled in a cylinder, along an axis1, under the action of an electric motor powered by a battery3arranged in an accommodating housing4formed in a leg5, running roughly orthogonal to the axis1and connected to the casing2.

Also connected to the casing is an elbowed operating handle6, with a leg portion7roughly parallel to the leg housing the battery5and a portion8, for connection to the accommodating leg5, running roughly parallel to the axis1.

Housed in a housing13in the connecting portion of the handle8is a mechanical and electrical locking rod9running roughly parallel to the axis1. In its continuation, on the side facing towards the battery housing4, the rod9bears a locking finger10.

The locking rod9also bears, laterally, an actuating trigger11projecting from the handle6through an aperture14, on the inside12, between the two portions7,8and a return finger15, running parallel to the rod9, onto which there is slipped a return spring16bearing against the end wall17of the housing13and against a shoulder18formed by the finger15. The locking finger10is shaped to exhibit a passage ramp19inclined towards the axis1from the rear20towards the front21of the tool, for the passage of the battery3as it slides into its housing4.

In the rest position, which is the locked position, the locking finger10is returned by the spring16projecting into the battery housing4. The rod9is moved into a position of retraction of the finger10against the action of the spring16. In the battery accommodating leg5, on the anterior side which is the opposite end to the operating handle6, and therefore to the rod and to the locking finger, and near the casing2, there is fixed, via one end23, an elastic leaf22, bearing a boss24at its free end forming a retaining finger facing towards the battery accommodating housing4. The leaf22runs roughly orthogonally to the axis1, but its free portion is, however, inclined backwards so as to be able to pivot about its fixed end23and so that the retaining finger24can move roughly parallel to the axis1, between a rest position, which is a locked position, in which it projects into the battery housing4, and a retracted position, in its tool housing38, against the elasticity of the leaf.

As far as the battery3is concerned, this battery being of roughly parallelepipedal overall shape, near its entry end face25, it has, on its two opposed lateral sides26,27, two passage ramps28,29for respectively negotiating the mechanical retaining finger24and the mechanical and electrical locking finger10. A slight recess or hollow30is formed slightly beyond the ramp28, exhibiting a ramp31inclined in the opposite direction to the ramp28to form, on the one hand, a boss32for the mechanical retention of the battery and, on the other hand, a housing30for accommodating the retaining finger24in the rest position. Here, the housing30is delimited not only by the ramp31but by another ramp33inclined in the opposite direction and situated at a distance away from the entry face25that is at least equal to the length of the leaf22considered in the direction in which the battery is introduced. Closer to its rear end face34, on the side27of the battery, there is a locking catch35comprising an undercut internal shoulder36, facing away from the entry face25, and in this instance a ramp37inclined like the passage ramp19of the locking finger10.

The fitting and removal of the battery3in the tool will now be explained.

Offering the battery3up via its entry face25, it is introduced into the housing4. It is pushed thereinto in the direction of the arrow39, roughly orthogonal to the axis1. The ramp29, collaborating with the ramp19of the locking finger10, retracts it into its housing13, against the action of the spring16. The battery continues to be pushed, the locking finger10sliding along the side27of the battery until the ramp28, collaborating with the retaining finger24, retracts it in its turn into its tool housing38against the elasticity of the leaf22, then until the retaining finger24, having passed the boss32, and through elastic relaxation of the leaf22, returns to the battery housing30.

In this position, the battery is not yet electrically connected, but is mechanically retained in the tool in that, in order to extract it, it would be necessary to pull on it to overcome the friction force needed for the boss32to move past the retaining finger24.

It will be noted that, because of the height or extent of the battery housing30, the battery can still move to some extent, without the electrical connection ever being made inadvertently.

By continuing to push the battery3into its housing4, it can be truly clipped in, that is to say mechanically and electrically locked, when the retaining catch35comes opposite the retaining finger10which, under the action of the spring16, is returned by sliding into the catch.

Conversely, to remove the battery3from its housing4, the trigger11is actuated against the action of the spring16to disengage the finger10from the catch35then the battery is pulled to electrically disconnect the electrical components of the tool. It still, however, remains mechanically secured to the tool, as long as the boss32has not been moved past the retaining finger24. It is only by forcing this boss past the finger24and overcoming the corresponding friction forces that the battery can be fully removed from the tool.