portable electric tool with compact electronics

Abstract

The present invention relates to a portable power tool comprising a housing containing: an electric motor; an electronic circuit board housed in a portion of said housing, said portion extending along a principal axis. According to the invention, said electronic circuit board comprises at least two interconnected printed circuit boards, said at least two printed circuit boards being arranged essentially circumferentially around said principal axis. Fig. 8

Description

Title of the invention: Portable electric tool with compact electronics 1. Scope of the invention

[0001] The field of the invention is that of corded or battery-powered portable electric tools. 2. Prior art

[0002] Portable power tools, such as screwdrivers, drills or the like, require an external power source for their operation and / or for data transmission.

[0003] This energy supply can be achieved via a battery or via a cable temporarily connected to the tool by a connector (male or female) generally located at one end of the tool.

[0004] These tools also require one or more electronic boards to function. These various electronic boards are used to manage: the tool's power supply, managing screwing, drilling, and other cycles... communication with an external control unit, displaying reports to the operator

[0005] These electronic cards can optionally be superimposed.

[0006] Classically, a portable electric tool includes a housing at one end of which is a rotating terminal element capable of driving in rotation and / or translation an accessory such as a drill bit or a screw socket.

[0007] The terminal member is connected to the output of a transmission whose input is connected to the rotor of a motor.

[0008] Extending from the motor are one or more electronic boards, to which the motor is connected, and then a connector linked to the electronic boards.

[0009] Generally, the connector part is separate from the electronic board and is connected to it by a cable harness. It is positioned longitudinally following the electronic board part.

[0010] There are also tools in which the connector pins are soldered onto a connector printed circuit board that is transverse to the tool. This connector printed circuit board is itself soldered to the main electronic board of the tool.

[0011] Furthermore, there are several solutions for positioning and holding electronic boards inside the housing of a tool.

[0012] The card can be held by screws directly on the housing, possibly with elastomer elements to limit vibrations on the card.

[0013] Another solution is to hold the electronic board by wedging it between two portions of the housing assembled together to form the housing.

[0014] Another solution is to place the electronic board in a sleeve (holding it for example with screws), then to insert the sleeve into the tool housing.

[0015] Whatever solution is implemented, the integration of electronic boards into existing tools poses some problems.

[0016] In particular, the integration of electronic boards into power tools impairs the compactness of the tools.

[0017] This results from several constraints, among which are the following.

[0018] First, the low-voltage powered electronic boards must maintain minimum isolation distances from the three (high-voltage) power cables supplying the three phases of the motor. This distance between the connector and the electronic boards results in an elongation of the tool housing.

[0019] Secondly, to be comfortably gripped by an operator performing tasks daily, the tool body must have a small-diameter gripping portion. This small diameter of the tool body, in a region where the connector and electronic boards are located, makes it difficult to install them while respecting the required isolation distances unless the electronic boards are moved further away from the connector.

[0020] In order to comply with these constraints, a sufficient distance in the longitudinal direction is prescribed between the electronic boards and the connector, which implies that the body of the tools is relatively long.

[0021] Furthermore, the systems for holding the electronic boards in the body of the tools are quite bulky: - the screws traditionally used to hold the cards take up a lot of space inside the tool; - card retention systems using sliding / clamping require a significant thickness of electronic cards to ensure that they are not damaged during assembly; - Sheath systems require additional parts which also take up space in the tool body; - Stacking cards requires inter-card connectors and elements to hold them together.

[0022] All of this has the effect of harming the compactness of the different elements and therefore in particular of lengthening the tools.

[0023] There is therefore a need to improve the integration of electronic boards within electrical tools. 3. Objectives of the invention

[0024] The invention aims in particular to provide an effective solution to at least some of these different problems.

[0025] In particular, according to at least one embodiment, an objective of the invention is to provide a technique for integrating electronic boards into an electrical tool which makes it possible to satisfy the constraints regarding the respect of isolation distances between the electronic boards and the connector while offering good ease of use.

[0026] In particular, the invention aims, according to at least one embodiment, to provide such a technique which makes it possible to compact, i.e. reduce the size, the integration of electronic boards.

[0027] Another objective of the invention is, according to at least one embodiment, to provide such a technique which contributes to ensuring good reliability in particular by providing a technique avoiding damage to the cards.

[0028] Another objective of the invention is, according to at least one embodiment, to provide such a technique which is simple to implement and / or robust and / or reliable and / or economical. 4. Presentation of the invention

[0029] To this end, the invention proposes a portable electric tool comprising a housing containing: - an electric motor; - an electronic card housed in a portion of said casing, said portion extending along a main axis.

[0030] According to the invention, said electronic card comprises at least two interconnected printed circuits, said at least two printed circuits being arranged in an essentially circumferential manner around said main axis.

[0031] Thus, according to this aspect of the invention, the printed circuits composing the electronic board of an electric tool are “wrapped” around the main axis of a portion of the casing.

[0032] It is thus possible to reduce the length of the electronic board, and therefore that of the tool, while: respecting a minimum isolation distance between the card and the connector, and providing a small crankcase diameter.

[0033] The invention thus makes it possible to provide a tool respecting the required isolation distance between the electronic board and the connector while being compact, which makes it comfortable to use for an operator who works with it to carry out operations.

[0034] According to one possible feature, said printed circuits are connected two-by-two by means of deformable conductive tabs.

[0035] According to one possible feature, said portion of said housing accommodates a support for said electronic card, said support having at least as many support faces as said electronic card comprises printed circuits, said faces extending in planes substantially parallel to said main axis.

[0036] According to a possible feature, a tool according to the invention includes means for securing said electronic card to said support.

[0037] According to one possible feature, said fastening means include retaining elements protruding from the surface of said support, said tabs including fixing openings each allowing the passage of one of said retaining elements.

[0038] According to one possible feature, said fixing openings are provided at free ends of said tabs.

[0039] According to one possible feature, said retaining elements are provided at the junction between two consecutive support faces of said support.

[0040] According to one possible feature, a tool according to the invention includes means for locking said retaining elements in said fixing openings.

[0041] According to one possible feature, said locking means include lugs extending laterally to said retaining elements along axes parallel to said support surfaces.

[0042] According to one possible feature, said locking means comprise slots formed in each of said retaining elements along a plane parallel to a support surface from which said retaining element protrudes.

[0043] According to one possible feature, at least some of said fixing openings have at their periphery at least one easing slot.

[0044] According to one possible feature, a tool according to the invention includes means for positioning said printed circuits on said support face.

[0045] According to one possible feature, said positioning means include pins protruding from the surface of at least some of said support faces, said pins being able to cooperate with complementary shaped housings provided in said printed circuits or in said tabs.

[0046] According to one possible feature, said support comprises a connector having at least one electronic contact capable of being connected to a power source, said support being traversed at least in part substantially along said main axis by at least one cable connected to said motor and / or to said electronic board.

[0047] According to one possible feature, said housing comprises a portion housing said motor extending along a main axis, the main axes of the housing portions housing said motor and said electronic board being coincident or forming an angle. 5. Description of the figures

[0048] Other features and advantages of the invention will become apparent from the following description of particular embodiments, given by way of simple illustrative and non-limiting example, and the accompanying drawings, among which:

[0049] [Fig-1] [Fig.1] illustrates a perspective view of an example of a tool according to the invention;

[0050] [Fig.2] [Fig.2] illustrates an example of an electronic board of a tool according to the invention, laid flat;

[0051] [Fig.3] [Fig.3] illustrates a detail of [Fig.2];

[0052] [Fig.4] [Fig.4] illustrates another detail of [Fig.2];

[0053] [Fig. 5] [Fig. 5] illustrates the electronic board shown in [Fig. 2] but rolled up around an axis;

[0054] [Fig.6] [Fig.6] illustrates an electronic card support of a tool according to the invention;

[0055] [Fig.7] [Fig.7] illustrates a detail of [Fig.6];

[0056] [Fig.8] [Fig.8] illustrates an electronic circuit board wrapped around the support shown in the [Fig.6];

[0057] [Fig.9] [Fig.9] illustrates a longitudinal section of a tool according to the prior art;

[0058] [Fig. 10] [Fig. 10] illustrates a partial perspective view of a tool according to the invention in which the support for the electronic card is in cross-section so as to make visible the holes that pass through it;

[0059] [Fig. 11] [Fig. 11] illustrates an electronic card wrapped around the support illustrated in [Fig. 6];

[0060] [Fig. 12] [Fig. 12] illustrates a cross-section of a tool according to the prior art.

[0061] 6. Description of particular embodiments 6.1. Structure 6.1.1. Power supply via cable

[0062] An example of a portable power tool according to the invention is shown in relation to Figures 1 to 8 and 10 to 12. This may include, in particular, a screwdriver, a drill, or other.

[0063] Such a tool includes a housing 10.

[0064] This housing 10 accommodates, at one of its ends, a connector 11 which allows the tool to be connected to a power supply and / or data exchange cable 12.

[0065] This cable 12 is connected to a controller (not shown) which incorporates the intelligence enabling, among other things, the power supply and control of the motor.

[0066] At the other end of the housing 10 is located a terminal member 13 capable of driving in rotation and / or translation an accessory such as for example a cutting tool (such as a drill bit...) or a screw socket...

[0067] Between connector 11 and terminal member 13, the housing 10 comprises: - a handful portion 14, - a portion of motorization 15, and - a portion of transmission 16.

[0068] The transmission portion 16 houses a transmission T, generally a gear transmission. This transmission T is connected on one side to the terminal member 13 and on the other side to the rotor R of a motor M housed in the motorization portion 15.

[0069] The portion of the handle 14 is intended to be gripped by an operator in order to manipulate the tool.

[0070] This portion of the handle 14 can extend along a principal axis essentially coinciding with the axis of the motor rotor, as shown in [Fig. 1]. Alternatively, it can extend along an axis forming an angle with respect to the rotor axis. This is then referred to as a pistol-grip type tool.

[0071] The handle portion 14 houses an electronic board 17. This electronic board 17 can be designed to perform various functions such as, for example, displaying information, controlling torque and / or angle measuring devices, exchanging information with an actuation trigger, bidirectional information exchange with the controller...

[0072] In this embodiment, the electronic board 17 comprises four printed circuit boards 170. However, in variations, the number of printed circuit boards 170 of the electronic board 17 may be different and will be at least two. It may thus be greater than four, and therefore, for example, be equal to 2, 3, 4, 5, 6...

[0073] The printed circuits 170 are arranged essentially circumferentially around the main axis of the handle portion 14. In other words, they are “wrapped” around this axis.

[0074] For this purpose, the printed circuits 170 are connected two-by-two by means of deformable conductive tabs 18.

[0075] More specifically, the electronic card 17 includes two tabs 18 which extend essentially parallel to each other and to which the printed circuits 170 are attached, preferably at regular intervals, by gluing or otherwise.

[0076] The portions 180 of tabs 18 located at the junction between two consecutive printed circuits 17 can be folded to wrap the printed circuits 17 around an axis, and thus form hinges in a way.

[0077] The portion of the housing 10 which houses the electronic card 17, in this case the portion of the handle 14, also houses a support 19 for the electronic card 17.

[0078] This support 19 has at least as many support faces 190 as the electronic card 17 has printed circuits 170. In the present embodiment, the support 19 therefore comprises four support faces 190. These support faces 190 extend in planes substantially parallel to the main axis of the portion of the housing 10 housing the electronic card 17, in this case the handle portion 14.

[0079] The tool includes means for securing the electronic card 17 to the support 19.

[0080] These means of securing, reversible or not, could for example be: - an elastic ring of the O-ring type surrounding the printed circuits and holding them pressed against the support faces; - glue to glue each printed circuit board 170 onto the corresponding support face 190; - screws; - rivets; - clips...

[0081] In the illustrated embodiment, these fastening means include retaining elements 191 protruding from the surface of the support 19.

[0082] In this embodiment, these retaining elements 191 are two in number and are positioned at the junction between two consecutive support faces 190. They are spaced at a center distance substantially identical to the center distance of the tabs 18.

[0083] The tabs 18 include, at each of their free ends, not connected to a printed circuit 170, a fixing opening 181 allowing the passage of one of these retaining elements 191.

[0084] Each retaining element 191 has a first end extending onto the surface of a first support face 190 and a second end extending onto the surface of the second support face 190 consecutive to the first.

[0085] The first of these ends includes a locking slot 192 formed along a plane essentially parallel to the plane of the first support face 190.

[0086] The second of these ends includes nipples 193 extending laterally to the retaining elements 191 along axes parallel to the support faces 190.

[0087] The slots 192 and the lugs 193 constitute means of locking the retaining elements 191 in the fixing openings 181, as will become clearer later in the description.

[0088] At least two of the openings 181 may have at their periphery at least one flexing slot 182. These flexing slots 182 are preferably provided on two end tabs 180 located on the same side of the electronic board.

[0089] In variants: - the slots 192 can be replaced by nipples 193, in which case there will be no slots 192; - the nipples 193 can be replaced by slits 192, in which case there will be no nipples 193; - the position of the nipples 193 and the slits 192 may be reversed compared to that shown in the drawings.

[0090] The tool includes in this embodiment means for positioning the printed circuits 170 on the support faces 190.

[0091] In this embodiment, these positioning means include pins 194 protruding from the surface of at least some of the support faces 190. These pins 194 are able to cooperate with housings 171 of complementary shape provided in the printed circuits 17 or in the tabs 18.

[0092] Preferably, at least one housing 171 will be provided in each printed circuit board 17, and more preferably at least two. As many pins 194 will be provided as there are housings 171.

[0093] The support 19 includes the connector 11, or at least its terminal block portion 110, provided with at least one electronic (or electrical) contact.

[0094] In the present embodiment, the terminal block 110 comprises three electrical contacts 111 suitable for being connected to a power supply source to supply the phases of the motor M. These contacts 111 are connected to the phases of the motor M by wires protected in a sheath 20 which passes through a hole 21 longitudinally through the support 19.

[0095] The terminal block 110 also includes electrical contacts 112, of any number, some of which are suitable for connection to a power supply and others to the controller. These contacts 112 are connected to the electronic board 17 by wires 22 which pass through a hole 23 provided for this purpose in the support 19 and preferably exit at the periphery of the support through an opening 24. These contacts 112 allow the electronic board 17 to be powered and to exchange information with the controller. 6.1.2. Battery power supply

[0096] When the connector 11 is not used to connect the tool to a cable 12 but to at least one battery, all the wires connected to the contacts 111, 112 are connected to the electronic board 17 and the electronic board 17 is connected to the motor M to enable, in addition to its other functions, the supply and control of the motor. 6.2. Assembly

[0097] The assembly of the electronic board 17 to the housing 10 is obtained in the following manner.

[0098] Before being assembled to the tool, the electronic card 17 extends in a plane as shown in [Fig.2].

[0099] To assemble the electronic card 17 to the tool, the two retaining elements 191 are inserted into two of the openings 181 of its tabs 18, located on the same side of the electronic card 17, taking care to slide the edge of the openings 181 into the slots 192. Thus, these two ends of the tabs 18 are held together with the retaining elements 191.

[0100] The first printed circuit 170, linked to the ends of the tabs 18 attached to the retaining elements 191, is then applied against the corresponding support face 190, taking care to insert the pins 194 of this support face 190 into the housings 171 of this printed circuit 170.

[0101] The portions 180 of the tabs 18 located between the printed circuit 170 which has just been pressed against the support face 190, are folded so as to apply the next printed circuit 17 against the corresponding support surface 190, taking care to insert the pins 194 of this support face 190 into the slots 171 of this printed circuit 170.

[0102] This type of operation is repeated twice to press the two other printed circuits 170 against the two following support faces 190.

[0103] The two retaining elements 191 are then introduced into the openings 181 of the two free ends of the tabs 18. The softening slots 182 make it easier to pass the nipples 193 through the openings 181.

[0104] The electronic card 17 is then secured and locked onto the support 19 of the tool. 6.3. Advantages

[0105] The technique according to the invention provides numerous advantages, including but not limited to: - the provision of a compact and comfortable tool to use insofar as the implementation of an electronic card wrapped around the tool makes it possible to reduce the length of the card, and to reduce the length and diameter of the tool; to improve the insulation of the motor power cables from the electronic board by routing them inside the electronic board support, thus avoiding the need, as is the case in the prior art illustrated in [Fig.9], to move the electronic board away from the connector to satisfy the level of insulation; this also helps to reduce the length of the tool.

Claims

Demands

1. Portable power tool comprising a housing (10) containing: - an electric motor (M); - an electronic card (17) housed in a portion (14) of said housing (10), said portion (17) extending along a principal axis, characterized in that said electronic card (17) comprises at least two interconnected printed circuits (170), said at least two printed circuits (170) being arranged essentially circumferentially around said principal axis, said portion (14) of said housing (10) housing a support (19) for said electronic card (17), said support (19) having at least as many support faces (190) as said electronic card (17) comprises printed circuits (170), said faces (190) extending in planes substantially parallel to said principal axis, said support (19) comprising a connector (11) provided with at least one electronic contact (111) capable of being connected to a power source,said support (19) being traversed at least in part substantially along said main axis by at least one cable (12) connected to said motor (M) and / or to said electronic board (17).

2. Tool according to claim 1 in which said printed circuits (170) are connected two-by-two by means of deformable conductive tabs (18).

3. Tool according to claim 1 or 2 comprising means for securing said electronic card (17) to said support (19).

4. Tool according to claims 2 or 3 wherein said fastening means comprise retaining elements (191) projecting from the surface of said support (19), said tabs (18) comprising fixing openings (181) each allowing the passage of one of said retaining elements (191).

5. Tool according to claim 4 in which said fixing openings (181) are provided at free ends of said tabs (18).

6. Tool according to claim 4 or 5 in which said retaining elements (191) are provided at the junction between two consecutive support faces (190) of said support (19).

7. Tool according to claim 4 or 5 comprising means for locking said retaining elements (191) in said fixing openings (181).

8. Tool according to claim 7 in which said locking means comprise studs (193) extending laterally to said retaining elements (181) along axes parallel to said support surfaces (190).

9. Tool according to claim 7 or 8 wherein said locking means comprise slots (192) formed in each of said retaining elements (191) along a plane parallel to a support surface (190) from which said retaining element (191) protrudes.

10. Tool according to claim 8 or 9 in which at least some of said fixing openings (181) have at their periphery at least one easing slot (182).

11. Tool according to any one of claims 1 to 10 comprising means for positioning said printed circuits (170) on said support face (190).

12. Tool according to claim 11 in which said positioning means comprise pins (194) forming protrusions on the surface of at least some of said support faces (190), said pins (194) being able to cooperate with housings (171) of complementary shape provided in said printed circuits (170) or in said tabs (18).

13. Tool according to any one of claims 1 to 12 in which said housing (10) comprises a portion (15) housing said motor (M) extending along a principal axis, the principal axes of the portions (14, 15) of housing (10) housing said motor (M) and said electronic board (17) being coincident or forming an angle.

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