Cordless power tool system

ES 2 247 461 T3

DESCRIPTION

Cordless motorized power tool system.

The present invention relates generally to powered mechanical tools. More particularly, the present invention relates to a cordless power tool system. More particularly, but not limited to the specific embodiment and / or use shown and described by way of example, the present invention relates to a system for cordless power tools with an improved interface for the battery pack. or stack. The present invention also relates to the method associated therewith.

Cordless power tools that include interchangeable battery units are well known in the prior art. For example, such a system is shown and disclosed in commonly assigned US Patent No. 3,952,239. The US Patent No. 3,952,239 discloses a tool system that uses individual tool heads, each of which incorporates its own essential elements such as a motor and a blade or collet. This type of system reduces the space requirements for the storage of said tool and increases the useful life of each motor. Another significant aspect of the type of systems disclosed in US Pat. No. 3,952,239 is the fact that they allow improved utilization of built-in nickel-cadmium batteries and an associated battery charger that specifically consists of high-cost elements of the system.

While prior art systems, including the type disclosed in, but not limited to, US Patent No. 3,952,239, have proven to be appropriate for numerous applications, they are all associated with certain disadvantages and / or limitations. . A further example of a prior art battery pack and charging device unit is disclosed in US Patent 5,391,972.

In accordance with one aspect of the present invention, a cordless power tool system is disclosed, comprising:

a rechargeable battery pack including a first housing and a battery pack terminal block, including a blade-shaped positive electrical connection element and a blade-shaped negative connection element; and a battery charger device including a second housing and positive and negative female connecting elements for receiving the positive and negative blade-shaped connecting elements, respectively, said second housing including a coupling part for coupling. mechanical part of the battery assembly, characterized in that said first casing defines a pair of laterally spaced guide elements, in that said battery pack connection block is arranged between said guide elements, because the second housing includes an open platform portion for vertically receiving the battery pack, and because the coupling portion defines a pair of separate grooves of lateral shape for receiving the pair of laterally spaced guide elements, so that the longitudinal movement of the battery pack towards the coupling part prevents the vertical movement of said battery pack with respect to the second casing.

According to another aspect of the present invention, a method is disclosed for carrying out the process of charging the battery pack for a power mechanical tool, without cables, said battery pack including a first casing and presenting a block connection of the battery set positive and negative blade-shaped connection elements and laterally separated guide elements, said method comprising the steps of:

arrangement of a battery charger having a second housing and positive and negative female connection elements embedded within said second housing, said second housing further having a coupling portion;

mechanical coupling of the battery pack and the charging device; and electrical coupling of the positive and negative female connection elements with the positive and negative blade-shaped connection elements, respectively, characterized by the arrangement of the battery pack so that the positive and negative blade-shaped connection elements negatives are arranged between the guide elements, by the arrangement of the battery charger device with an open platform with which the battery pack is vertically coupled, by the arrangement of the battery charger such that the coupling part comprises a pair of laterally spaced slots and because the guide elements and the grooves are slidably engaged to substantially prevent vertical displacement of the battery pack relative to the charging device.

Additional benefits and advantages of the present invention will be apparent to those skilled in the art to which the present invention pertains from a reading of the following description of the preferred embodiment and the appended claims, taken in conjunction with the accompanying drawings. .

Figures 1A-1C are illustrations of a first cordless power tool of a cordless power tool system constructed in accordance with the description of a first embodiment of the present invention.

Figure 2 is an enlarged and disassembled perspective view of a first set of batteries of the cordless power tool system shown in Figure 1A.

Figure 3 is a plan view of the battery pack of Figure 2.

Figure 4 is a front view of the battery pack of Figure 2.

Figure 5 is a right side view of the battery pack of Figure 2.

Figure 6A is an enlarged, disassembled, perspective view of a tool connection block supported by the cordless power tool of Figures 1A-1C.

ES 2 247 461 T3

Figure 6B is an end view of the main body part of the tool connection block.

Figure 7 is a perspective view of the connection block of the battery pack of Figure 2.

Figure 8 is a cross-sectional view showing the interface between the battery pack and the tool.

Figure 9 is a right side view of a second battery pack for the cordless power tool system of the present invention.

Figure 10 is a right side view of a third battery pack of the cordless power tool system of the present invention.

Figure 11 is a partially disassembled and partially cutaway view showing a charging device for the battery pack of the system of the present invention, shown in operative association with the first battery pack.

Figure 12 is a perspective view of a charging device of the battery pack of Figure 11.

Figure 13 is a perspective view of a second cordless power tool of the system of the present invention, operatively associated with a transformer.

Figure 14 is a cross-sectional view showing the interface between the cordless power tool and the transformer.

Figure 15 is a side view of a third cordless power tool of the system of the present invention.

Figure 16 is a schematic representation showing the compatibility of the numerous batteries and tools of the present invention.

Referring generally to the drawings, a cordless power tool system constructed in accordance with the description of a preferred embodiment of the present invention is shown. The cordless power tools of the system include, by way of example, a circular power saw (10) (Figure 1), a reciprocating saw (12) (Figure 13), and a chuck (14) (Figure 15). Each of the tools 10-14 includes a conventional direct current motor (not shown) adapted to be driven with a common voltage. In the exemplary embodiment, tools 10-14 are powered by 24 volt electricity. It will be apparent to those skilled in the art that the present invention is not limited to the specific types of tools shown in the drawings nor is it limited to specific voltages. In this regard, the present invention can be applied to virtually any type of power power tool and any voltage supply.

Referring also to the drawings, the system of the present invention further includes a first set of rechargeable batteries (16). The system of the present invention generally includes an alternating current / direct current transformer (18) and a battery charger device (20) for charging the battery pack (16). The battery charger device (20) is shown in Figure 11 partially cut away and operatively associated with the battery pack (16). The AC / DC transformer is shown in Figure 13 removably coupled to the reciprocating saw (12).

The focus of the present invention pertains more particularly to the interfaces between the tools (10-14) and the battery pack (16), the interfaces between the tools (10-14) and the alternating current / direct current transformer. (18), and the interfaces between the battery pack (16) and the battery charger device (20). During the remainder of this detailed description, it will be understood that the tool interface of each of the tools 10-14 is substantially identical.

With particular reference to Figures 2 to 6, the rechargeable battery assembly (16) of the present invention is shown generally including a housing (22), a battery (24) which in the exemplary embodiment it is a 24 volt nickel) cadmium battery, and a battery pack connection block (26). The housing (22) is shown to include first and second semi-wrap-shaped halves (28) and (30) that are attached to a longitudinally extending parting line (32). Alternatively, it will be understood that said housing 22 may include a pair of halves joined by a parting line extending laterally, or numerous other constructions that include two or more parts of the housing.

The first and second half-wrap-shaped halves (28) and (30) of the wrap-around body (22) cooperate to form an upper part (34) defining a first chamber (36) and a lower part (38) defining a second chamber (40). The mentioned first chamber (36) receives the battery pack connection block (26), while the second chamber (40) receives the battery (24). The battery pack connection block (26) is fixed preventing lateral and longitudinal displacement with respect to the housing (22) except for minimum part tolerance stacking. In one application, the battery pack housing 22 has an overall length of approximately 11.5 cm, and an overall width of approximately 9.5 cm, and a height of 9.5 cm. approximate.

In the exemplary embodiment, the first and second semi-wrap-shaped halves (28) and (30) of the housing (22) are each constructed unitary from a rigid plastic or other appropriate material. The first and second half-wrap-shaped halves (28) and (30) are joined by threaded fasteners (42). The threaded fasteners (42) pass through cooperating openings (44) and threaded projections (46) integrally formed with the semi-wrap-shaped halves (28) and (30). During assembly, the fasteners (42) form threads on the threaded projections (46) of the housing (30). In the exemplary embodiment shown, the first semi-wrap-shaped half (28) of the wrap-around body (22) is formed to include a peripheral groove (50) adapted to receive a mating projection (not shown). specific) that extends peripherally around the second half in a semi-enveloping manner (30).

ES 2 247 461 T3

To facilitate detachable coupling of the battery pack (16) from the tool (10), the top (34) of the housing (22) is formed to include a pair of guide elements (52). Said guide elements (52), which will be further described later, are slidably received in cooperating grooves (54) defined by guides (55) formed in a housing (56) of the tool (10). To further facilitate removable engagement of the battery pack (16) with the tool (10), the top (34) of the housing (22) defines a recess (58). Said recess (58) is adapted to receive at least one retaining element (59) arranged in the housing (56) of the tool (10). Said retention element (59) has a conventional construction and mode of operation, and is biased by a spring to a downwardly directed position to engage the recess (58) during insertion with the rechargeable battery pack (16). Thus, removal of the battery pack 16 is prevented until the spring bias of the retainer 59 is overcome in a conventional manner as far as the present invention is concerned.

Referring again to Figures 2 to 5 and additionally to Figures 7 and 8, the battery assembly connection block (26) is shown generally including a main body part (60) constructed of rigid plastic or other material. appropriate and a series of connecting elements (62). Said connecting elements (62) are generally flat blade-shaped connecting elements, each oriented in a plane substantially perpendicular to the lower surface or floor (64) (shown in Figure 2), partially defining the upper chamber. (36) of the housing (22). Each of the blade-shaped connecting elements (62) includes a first end (66) that extends downwardly from the main body portion (60). Each of the blade-shaped connecting elements (62) further includes a second end (68) extending forward. In the preferred embodiment, the second ends (68) of the blade-shaped connecting elements (62) are spaced from the bottom surface in an upward direction (64). As will be more fully appreciated below, said spacing of the blade-shaped connecting element (62) from the bottom surface (64) provides improved clearance around said blade-shaped connecting element (62) and reduces the risk. of contamination of said connection elements (62) with dirt and other residues. Furthermore, said spacing of the connection elements (62) with respect to the lower surface (64) allows the contact elements of the charging device (20) to be more completely enclosed by insulating material. This aspect of the present invention will be described in more detail later. Furthermore, in the preferred embodiment, the leading tips of the blade-shaped connecting elements (62) and the guide elements (52) are cross-aligned.

The main body (60) of the connecting block (26) is shown to be housed between the semi-wrap-shaped halves (28) and (30) of the wrap-around body (22). Such an arrangement improves assembly by allowing the connecting block (26) to be first electrically coupled to the battery (24) and subsequently encased between the semi-wrap-shaped halves (28) and (30). The main body (60) is shown to include a pair of arc-shaped slots (70) disposed in a lower surface thereof to accommodate the threaded protrusions (46) of the housing (20) during assembly. Similarly, an upper main body portion (60) includes a recess (72) to accommodate the recess (58) in the housing (22). The main body part (60) is shown further including a series of insulating parts (74) disposed between adjacent blade-shaped connecting elements (62) and also positioned outside the blade-shaped terminals (62) of the most extreme end. far away. The insulating parts (74) protect the blade-shaped connecting elements (62) from accidental contact or damage.

In the exemplary embodiment shown, the battery pack connection block (26) includes four blade-shaped connection elements (62). Two of said blade-shaped connecting elements (62) are the positive and negative connecting elements for the battery (24). A third connection element (62) can be used to control the temperature of the battery (24) and a fourth connection element can be used to identify the battery. The specific functions of the third and fourth blade-shaped connecting elements 62 are outside the scope of the present invention and there is no need for them to be described in further detail herein. Those skilled in the art will appreciate that additional connecting elements 62 could be used without departing from the scope of the present invention.

With particular reference now to Figures 6A, 6B and 8, a connecting block (76) supported by the tool (10) will be described. The tool connection block (76) is coupled to the housing (56) to prevent lateral displacement relative to the housing, except for tolerance stacking of the parts. In the exemplary embodiment, the tool connection block (76) is coupled to the housing (56) in order to prevent longitudinal displacements. However, as explained below, certain applications may require limited longitudinal movement of the tool connection block (76).

The tool connection block (76) is shown to generally include a main body part (80), a first connection element or negative first connection element (82), and a second connection element or negative connection element. positive connection (84). The first connecting element (82) includes a negative male connecting element (86) and a negative female connecting element (88). Similarly, the second connecting element includes a positive male connecting element (90) and a positive female connecting element (92). As will be further explained later in greater detail, the female connection elements (88) and (92) are adapted to receive the positive and negative blade-shaped terminal elements (62) of the battery pack connection block ( 26). The male connection elements (86) and (90) are adapted for electrical coupling.

ES 2 247 461 T3 the tool (10) with the transformer (18). As shown in Figure 8, when the battery pack (16) is operatively connected to the tool (10), the male connection elements (86) and (90) of the tool connection block (76 ) are received within free spaces, shown in the exemplary embodiment as openings (96), arranged in each of the guide elements (52). Alternatively, the spaces (96) for housing the male connection elements (86) and (90) may be in the form of grooves provided in said guide elements (52) or the latter may be recessed. It will be understood that said male connection elements (86) and (90) do not perform any electrical function when the battery pack (16) is coupled to the tool (10).

As particularly shown in the end view of Figure 6B and the cross-sectional view of Figure 8, the main body (80) of the tool connection block (76) includes a series of frame structures ( 98), each defining a window or opening (100) to receive and guide one of the blade-shaped connecting elements (62). The female connection elements (88) and (92) of the tool connection block (76) are disposed within adjacent frame structures (98). Said frame structures (98) are generally "U" shaped and each includes a pair of longitudinally extending limbs (102) connected by an intermediate segment (103). The openings (104) are disposed between adjacent frame structures (98) to receive the insulating portions (74). In the exemplary embodiment, the ends of each of the extremities (102) of the frames (98) are generally triangular in shape, in order to define entry guide surfaces for the insulating portions (74) toward the openings. (104) and also for the connecting blades (62) towards their corresponding opening (100).

As shown more clearly in Figure 6B, the main body portion (80) of the tool connection block (76) includes a pair of laterally spaced guide elements (97). The main body portion (80) further includes a pair of openings (101) that receive the male connection elements (86) and (90). Said guide elements (97) are adapted to be received within slots (99) arranged in the housing (30) of the battery pack (16) immediately below the guide elements (52). As will be further described later, the laterally spaced guide elements (97) establish an intimate fit with the slots (99) to precisely align the tool connection block (76) with the tool assembly connection block. batteries (26).

With specific reference to Figure 11, a partially cutaway view of the battery charger device (20) of the system of the present invention is shown, operatively associated with a set of batteries (16) that has been partially removed. for illustrative purposes. Figure 12 is an elevated perspective view of the charging device (20) shown without the battery pack (16). In the preferred embodiment, the charger device (20) is a non-isolated charger. As used herein, the term "non-isolated" will be understood as meaning that the output voltage is not isolated from the input voltage of the electrical network. The battery charger device (20) includes a housing (110) that includes an open recessed platform (111). The battery charger housing (110) further includes a rear coupling portion (112) for mechanically engaging the top portion (34) of the battery pack housing (22).

The rear coupling portion (112) includes a pair of opposing slots (54) similar to those provided in the tool housing (56) that receives the guide elements (52) of the battery pack (22). The battery charger device (20) further includes a set of female connecting elements having at least one pair of female connecting elements (114) for receiving the positive and negative blade-shaped connecting elements (62) of the set. battery connection cable (26). A cable (116) supplies alternating current electricity (eg, 120 volt electricity) to the battery charger device (20). The adjacent arrangement of the positive and negative connecting blades (62) allows a charger circuit design that reduces electromagnetic interference.

The housing of the battery charger (110) is shown more clearly in Figure 12, defining a series of blade-shaped connection openings (140) corresponding in quantity with the blade-shaped connection elements (62) battery pack (16). The blade-shaped connection openings (140) are defined by insulating portions (142) adapted to cooperatively receive the insulating portions (74) of the battery pack (16). In this regard, the adjacent insulating parts (142) are separated defining openings (144) to receive the insulating parts (74). Each of said insulating portions (142) of the magazine body (110) includes a pair of vertically oriented side walls (146) and a horizontally oriented top segment (148). The upper segments (148) serve to protect the connection elements (114) from any type of accidental contact or damage. Since the blade-shaped connecting elements (62) of the battery pack (16) are vertically spaced from the lower surface (64), the upper segments (148) can be arranged between said parts. Those skilled in the art will understand that the remainder of the loader device 20 is of conventional construction with respect to the present invention.

The set of batteries (16) is loaded into the charger (20) by first placing said set (16) vertically on the platform (111) and then sliding the set (16) in a posterior direction to couple it to the guide elements (52) of the assembly (16) with the slots (54) of the magazine (20). While on the platform (111), the assembly (16) is supported by ribs (113). The open platform (111) facilitates the positioning of the assembly (16) in the magazine (20), since said assembly (16) is roughly aligned, first of all, with the magazine (20) by placing it on said platform (111) and is then mechanically and electrically connected by a sliding action in the rear direction. Thus, a mechanical interface with improved stability is disclosed. In the event that a user lifts the assembly (16) and the magazine (20) holding the assembly (16) only, the

ES 2 247 461 T3 guide elements (52) and the coupled grooves (54) prevent potential charge damage to the electrical connection elements. Thus, the combination of the loading platform (111) and the rear coupling portion (112) provides for improved ergonomic loading characteristics and mechanical stability for connection.

Referring again to Figure 13, the transformer (18) of the system of the present invention is shown operatively coupled with the reciprocating saw (12). Again, it will be appreciated that the specific tool 12 shown in Figure 12 is merely an example. In this regard, the transformer (18) is operative to be used with the circular saw (10) shown in figure 1, the chuck (14) shown in figure 15, or any other similar tool constructed in accordance with the teachings of the present invention. The transformer (18) of Figure 13 is specifically adapted to transform the alternating current electrical supply from the network to 24 volt direct current.

In the preferred embodiment, the transformer (18) is a non-isolated transformer and includes a housing (120) and an electrical supply cable (122). Said housing (120) is substantially similar to housing (22) of battery pack (16). In this sense, said casing (120) includes first and second semi-casing shaped halves joined by a longitudinally extending parting line. Alternatively, the housing (120) may include three (3) or more parts. An upper portion (122) of the housing (120) includes a pair of guide elements (124) similar to those of the battery pack (16).

With continued reference to Figure 13 and further referring to Figure 14, the transformer (18) is shown including a pair of female connection elements (128) adapted to receive the male connection elements (86) and (90). ) from the tool connection block (76). The female connection elements (128) are recessed inwards from the upper part (122) of the housing (120) of the transformer (18). In the preferred embodiment, the female connection elements (128) are recessed into the housing (120) of the transformer (18) by approximately 8mm or more. The electrical supply in alternating current is transformed into a supply in direct current by means of the transformer (18) and is supplied to the tool (12) by means of the connection elements (128). When the transformer (18) is operatively installed in the tool (12), the female connection elements (88) and (92) of the tool connection assembly (76) are not electrically operative.

As described above, the exemplary tools 10-14, fully shown in the figures, are specifically designed to operate on 24 volt direct current electricity. Referring to the schematic drawing of Figure 16, the system of the present invention is shown to further include a second (B) and a third (C) lines of cordless motorized power tools specifically designed to operate on alternating current. With the exception of their motors, said second and third lines (B) and (C) of the mechanical tools are substantially identical to the tools (10-14) of the first line (A). For identification purposes, the tools of the second (B) and third (C) lines are denoted in the drawings by common reference numerals that are designated prime and double prime, respectively. It will be understood that tools 10'-14 'and 10 "-14" are driven by second and third voltages, respectively. In the exemplary embodiment, the second and third voltages are one less and one greater than the first voltage, respectively. The multiple lines (AC) of the tools operatively actuated by different values ​​of voltages provide the consumer with a wide selection range to suit specific power supply needs.

As shown in Figures 9 and 10, the system of the present invention is shown including a second (16 ') and a third (16 ”) battery assemblies for supplying electricity to the second and third lines, respectively. The second (16 ') and the third (16 ") battery packs are substantially identical in construction to the first battery pack (16). For this reason, the reference numerals used above to refer to the first set of batteries (16) will be used to identify common elements of the second (16 ') and third (16 ") sets of batteries.

The third set of batteries (16 ") differs from the first set of batteries (16) in that its housing 22 is substantially larger in the longitudinal direction in order to accommodate additional battery cells. In the exemplary embodiment, the width and height dimensions of the third set of batteries (16 ") are identical to the dimensions corresponding to the first set of batteries (16). The guide elements (52) of the third battery set (16 ") are correspondingly longer as are the grooves (54) formed in the housing bodies (56) of the tools (10" -14 ") of the third line.

The system of the present invention is intended to prevent the operational coupling of any set of batteries (for example, -16- or -16 "-) with a tool of lower voltage value in order to protect the electric motors against any damage. . For example, the third set of batteries (16 ") with higher voltage is designed to be blocked for both the tools (10-14) of the first line (A) and the tools (10'-14 ') of the second. line (B). In this sense, the housing (22) of the third set of batteries (16 ") is shown to include a locking rib (130). In the embodiment shown, said rib (130) extends approximately 86 millimeters from a reference wall (132) and is approximately 2 millimeters high and 2 millimeters wide. Said reference wall (132) normally limits the movement of the guide elements (52) with respect to the grooves (54). An appropriate abutment surface (133) will engage the rib (130) and prevent engagement of the third set of batteries (16 "), which has a higher voltage, with the connection blocks (76) of the tools of the first line (A) and second line (B).

With particular reference to Figure 5, the first set of batteries (16) is designed to be locked against the lower voltage tools (10'-14 ') of the second line (B) and

ES 2 247 461 T3 will not be long enough to mate with the third line connection block (C). The first set of batteries (16) has a locking rib (134) that extends approximately 14 millimeters from the reference wall (132). Again, said locking rib (134) has a height of approximately two millimeters and a width of approximately two millimeters. Although not specifically shown, it will be understood that the grooves (54) of the tools (10-14) of the first line (A) are formed to receive the locking rib (134) while the grooves of lower voltage line tools (B) will not.

With specific reference to Figure 9, which shows the second set of batteries (16 '), it will be understood that said second set of batteries (16') is not specifically designed to be mechanically locked against the engagement of either tool. from any of the lines (AC). However, the length of the battery set (16 '), which in the preferred embodiment is identical to that of the first battery set (16), is insufficient to mate with the connection block of the third line (C) of tools. . The battery pack (16 ') is adapted to operate on the first and second tool lines (A) and (B). In an alternative arrangement discussed above, in which the third set of higher voltage batteries (16 ") has an identical length to that of the first and second sets of batteries (16) and (16 '), the second set of batteries of lower voltage (16 ') would not need to be blocked against connection with higher voltage tool line tools (C). However, there may not be enough power for the intended uses. The broken line between the battery packs (16) and (16 ') and the tools of the third line (C) shown in figure 16 indicates said alternative in which the electrical coupling is not impeded.

The coupling of the battery pack (16) with the housing (56) automatically produces the alignment or centering of the blade-shaped connection elements (62) of the battery pack (16) with the female connection elements (88) and 92) of the tool connection block (76). When the battery pack (16) is inserted into the tool housing (56), the alignment of the connection blades of the assembly (62) and the female connection elements of the tool (88) and (92) occurs in two stages. In a first stage, the guide elements (52) are loosely engaged in the tool engagement grooves (54). The total displacement of the battery pack (16) with respect to the housing (56) is approximately 60mm. In a second stage, which occurs during the last 22 mm of movement of the assembly (16) with respect to the casing (56), the grooves (99) in the casing (30) of the battery pack (16) engage with the guide elements (97) of the tool connection block (76) with a close fit. In the preferred embodiment, the housing (30) and the alignment guide elements (97) exhibit tight engagement. This coupling produces precise alignment of the battery pack (16) with the tool connection block (76) and, in turn, aligns the assembly connection block (26) with the tool connection block (76 ). Typically, the blade shaped connecting elements (62) of the battery pack (16) will mate with the female connecting elements of the tool (88) and (92) without further alignment. If the blade-shaped connecting elements (62) are curved, then said blade-shaped connecting elements (62) can be engaged with an associated frame structure (98) of the tool connecting block (76). The conical ends (102) of the frame (98) can facilitate the straightening of a blade-shaped connecting element (62) that is slightly curved. If the blade-shaped connecting member (62) is noticeably curved, the frame (98) prevents the connecting blade (62) from entering the opening (100).

As described above, it may alternatively be desirable to allow the tool connection block (76) to slide longitudinally in the tool housing (56). When the set connecting blades (62) are inserted into the female connecting elements of the tool (88) and (92) in such an arrangement, the set connecting blades (62) engage with the connecting elements. female tool connection (88) and (92) and move the tool connection block (76) back slightly. For example, such a displacement may be on the order of approximately 2mm. When the tool connection block (76) reaches said displacement limit with respect to the tool housing (56), the connection blades of the assembly (62) are inserted between the female connection elements of the tool (88 ) and (92). Then, the blade-shaped connecting elements of the assembly (62) are firmly clamped between the female connecting elements of the tool (88) and (92). If the battery set (16) moves with respect to the tool housing (56), due to vibrations of said tool (10) along the axis parallel to the guide elements (52), the set (16 ) and the tool connection block (76) move together. Said joint displacement of the tool connection block (76) and the battery pack (16) can reduce wear on the assembly connection blades (62) and the female connection elements of the tool (88) and (92).

With particular reference to Figure 2, the battery pack (16) of the present invention is shown to include projecting elements (160) to facilitate removal of the battery pack (16) from the tool housing (56) or the magazine (20). In the exemplary embodiment, each of the housing halves (28) and (30) include a pair of vertically spaced protruding elements (160), disposed on one side of the housing (22) adjacent to the rear side of said housing (22). Each of said projecting elements (160) is shown to be curved in a convex way and has a front part that the user can directly engage with the index finger or thumb. For example, the width of the battery pack (16) allows the user to engage an upper projecting element (160) of the second half of the housing (30) with the right thumb and an upper projecting element (160) of the first half of the housing. body wrap7

ES 2 247 461 T3 vente (28) with the right index finger. The projecting elements (160) can be used in a similar way when the battery pack (16) is inverted in the charger (20).

The present invention provides a number of advantages. An advantage of the present invention results from the provision of a battery pack for a cordless power tool with first and second housing halves, and defining upper and lower chambers. A battery may be located in the lower chamber and a battery pack connection block may be located in the upper chamber. Such a construction simplifies assembly, increases the durability of the set, and is particularly suitable for heavy sets that have a large number of battery cells.

A second advantage of the present invention results from the provision of a battery pack for a cordless power tool having longitudinally extending guide elements for tool engagement and longitudinally extending connecting blades, located between said guide elements. The front tips of said connecting blades and the guide elements have cross-aligned front tips. Such a construction simplifies and contributes to the precise alignment of the connecting blades with the guide elements, thereby contributing to the alignment of the connecting blades of the assembly with the connecting elements of the tool.

A third advantage of the present invention results from the provision of a battery pack for a cordless power tool having a housing that defines an upper chamber that receives a connection block. Said connection block includes a series of connection elements of the assembly that are perpendicular and are spaced from the lower surface of the upper chamber, thus providing an improved clearance around the connection elements and further reducing the possibility of contamination of the connection elements with waste.

A fourth advantage of the present invention results from the method of electrical and removable interconnection of a battery pack with a tool connection block of a cordless power tool. The battery pack is first roughly centered along a longitudinal axis of the tool handle by engaging guide elements with cooperating guide elements supported by the tool. The battery pack is then precisely centered by engaging the battery pack connecting elements, by engaging the tool connecting block with the battery pack.

A fifth advantage of the present invention is the provision of a battery pack for a cordless power tool that includes appropriate protrusions to facilitate manual removal.

A sixth advantage of the present invention results from the fact that it discloses a cordless power tool system, which includes a set of rechargeable batteries with male or protruding connection elements (for connection with female or recessed connection elements of a tool and to the female or lowered connection elements of a charger), a non-insulated AC / DC transformer having female or recessed connection elements for coupling with said tool, and a non-insulated charger with recessed connection elements for coupling with said battery pack. The use of non-insulated components (compared to insulated components) simplifies construction and reduces costs. The present invention provides a transformer with female connection elements and a set with male connection elements that are mechanically and electrically compatible with a tool having both male and female connection elements. This fact allows the system to be powered by a cordless direct current set or a corded ac / direct current transformer, and allows the user flexibility in the choice of electrical supply sources.

A seventh advantage of the present invention results from the fact that it discloses a cordless power tool system, which includes a charger having a housing with an open recessed platform for vertically receiving a set of rechargeable batteries and a part of coupling (preferably grooves) to carry out mechanical alignment of the battery pack and charger connection elements, and further to mechanically connect the battery pack to the charger so that longitudinal movement of the battery pack towards the coupling part prevents vertical movement of the battery pack relative to the housing. The process of vertically loading the assembly into an open magazine deck, initially prior to engagement with the guide elements of the assembly in the magazine engagement slots, simplifies alignment of the assembly with the magazine slots. This method is particularly suitable for large and heavy battery packs.

Although the present invention has been described and illustrated in the drawings herein with reference to a preferred embodiment, it will be apparent to those skilled in the art that numerous changes and substitutions can be made to elements thereof, without departing from the scope of the present invention, as defined in the claims. Furthermore, numerous modifications may be made to adapt a particular situation or material to the description without departing from the basic scope of the description. Therefore, it should be understood that the present invention is not limited to the specific embodiment shown by the drawings and described herein, given as the best mode of construction to carry out the present invention, but that the present invention will include all embodiments within the scope of the appended claims.