A working kit suitable for hobby work as well as constructional and the like heavy duty work, comprising
- (I) an electric rotary power tool apparatus holdable by hand during operation and consisting essentially of
- (A) a first building block comprising
- (1) an apparatus casing consisting essentially of an elongated assembly having a longitudinal axis and comprising
- (1.1) an enveloping shell extending generally in the direction of said longitudinal assembly axis, and having an open front end and an open rear end;
- (1.2) a first transverse wall being integral with said enveloping shell and extending across the interior of said shell in a region thereof intermediate said front end and said rear end and being axially spaced from both said shell ends so as to divide the shell interior into a forward chamber and a rearward chamber;
- said first transverse wall having a throughhole therein;
- (1.3) a second transverse wall across said open rear end of said shell and being detachably mounted therein;
- said second transverse wall having an opening therein;
- and
- (1.4) a speed-reducing unit mounted on said second transverse wall on the side thereof facing toward said first transverse wall, and being adapted for fitting into said rearward shell chamber;
- said speed-reducing unit comprising a driven power-transmitting shaft having a front shaft end adapted for fitting through said first transverse wall throughhole and protruding therefrom into said forward shell chamber;
- said speed-reducing unit comprising a gear train consisting essentially of a plurality of gears and a number of transmission shafts each bearing at least one of said gears, one of said gears being a pinion, and one of said transmission shafts being a driven power-transmitting shaft, said transmission shafts being rotatingly supported in said first and second transverse walls, respectively;
- said gear train being adapted to reducing the speed of said pinion to that of said driven shaft in a ratio of from about 2:1 to about 12:1;
- and
- (B) a second, rearward building block comprising
- (2) a direct current electric motor comprising
- (2.1) a motor housing comprising a surrounding hull, a forward hull end and a rearward hull end wall, said motor housing being adapted for having said forward hull end firmly connected with said second transverse wall on the outside thereof;
- (2.2) driving rotor shaft means having a longitudinal axis being substantially parallel with said longitudinal assembly axis and extending through the interior of said motor housing, said driving rotor shaft means comprising a rotor shaft being rotatably supported in said opening of said second transverse wall, and having a forward shaft end extending into said rearward shell chamber and bearing said pinion therein, for drivingly engaging said gear train;
- (2.3) a rotor mounted inside said motor housing on said rotor shaft for rotating the latter;
- (2.4) permanent magnet stator means adapted for generating an electromagnetic field in cooperation with said rotor adapted for excitation by a direct electric current having a potential of about 8 to 30 volts and an amperage sufficient for affording a power output of said motor, when idling, of at least 180 watt, and of at least about 620 watt under load;
- (2.5) commutator means comprising
- (2.5.a) a commutator consisting essentially of collector segments and being mounted on said rotor shaft between said rotor and said rearward hull end wall;
- (2.5.b) first and second brush means mounted in said motor housing and being biassed toward said collector segments for electrically conductive contact therewith and for delivery direct electric current to said rotor;
- (2.5.c) first and second fixed contactors being electrically conductively connected with said brush means and being mounted stationary in said rearward hull end wall and having terminal contactor portions bearing contactable terminal regions thereon located in an interspace, beyond said rearward motor hull end wall, in said rearward building block, said contactable regions being located generally in a common planar interspace contact zone;
- (2.5.d) electrically conductive lead means adapted for connecting said first brush means with said first fixed contactor, and said second brush means with said second fixed contactor, and being adapted for carrying direct electrical current of the voltage and amperage defined, supra, substantially free from electrical power losses;
- (4) first electrical switch means being adapted for switching a direct electrical current having the voltage and amperage defined, supra, and comprising
- (4.1) a first supporting member having at least one electrically insulating face spaced from and substantially parallel with said planar interspace contact zone,
- said contactable terminal regions being arranged about a first central switch axis being normal to said electrically insulating face of said first supporting member;
- said supporting member being adapted for pivoting displacement about said central switch axis, between a neutral position thereof and at least one activating position;
- (4.2) socket throughholes through said supporting member and being adapted for receiving therein the prongs of an electrical plug being electrically connectable to a source of direct electrical current;
- (4.3) at least two shiftable contactor elements being mounted on said electrically insulating face of said first supporting member so as to be insulated from each other, each of said contactor elements being associated with a different one of said socket throughholes to make substantially loss-free contact with a prong of a plug inserted in the respective throughhole;
- and each of said shiftable contact members having a contact face of curved configuration about and on opposite sides of said first central switch axis;
- (4.4) first biassing means associated with said rearward hull end wall and comprising first and second engagement means,
- (4.6) first fixed mounting means adapted for holding said first and second fixed contactors firmly in position therein relative to said first central switch axis, and being mounted fixedly on the outside of said rearward motor hull end wall;
- said first engagement means being mounted on said first fixed mounting means, and said second engagement means being mounted on said first supporting member, said first and second engagement means being engaged with one another in a manner such that said supporting member is biassed toward said first planar contact face and said first mounting means;
- (4.7) restoring means for restoring said first supporting member automatically form an activating position to said neutral position;
- said rearward building block further comprising
- (5) a cap member adapted for covering at least a substantial portion of said surrounding hull of said motor housing and having a cap end wall extending substantially parallel with and spaced from the outside of said rearward housing end wall, an internal chamber being left free between said rearward hull end wall and the inner face of said cap end wall, through which internal chamber said first planar contact plane extends;
- said first supporting means being located inside said cap member vis-a-vis said cap end wall;
- those socket throughholes being associated with said two shiftable contactor elements extending from outside said cap member and through the latter and also through said first supporting member, and two other, additional throughholes extending from outside said cap end wall and through said first supporting member thereon, and opening out of said electrically insulating face thereof to register with said contactable terminal regions of said first and second fixed contactors, respectively, when said supporting member is in neutral position;
- said first and second engagement means of said first biassing means being pivotably engaged with each other, whereby said first supporting member in said cap member can be pivoted about said first central switch axis relative to said first mounting means by at least a small angle;
- and, when said first supporting member is in activated position, said biassing means urge said shiftable contactor elements against said contactable terminal regions of said first and second fixed contactors;
- (II) at least one of the following kit items:
- (a) an electrical cable having two ends and comprising at one end thereof connecting means for attachment to a source of direct electrical current, and at the other end an electrical plug comprising prong-receiving holes therein being electrically conductively connected, through said cable, with said connecting means, and prongs adapted for being mounted fixedly in at least one of (i) said socket throughholes of said first supporting member, and (ii) said prong-receiving holes of said plug;
- (b) a handle part having at least two opposite handle sidewalls and being firmly and detachably connectable with said first building block, said handle part having a central longitudinal axis extending between said handle sidewalls and transversely to said central longitudinal motor housing axis;
- said opposite handle sidewalls adapted for freely supporting said cap member and said first supporting member therein to be pivotable about said first central switch axis between said neutral position and an activating position;
- said handle part comprising
- (7) second electrical switch means adapted for switching a direct electrical current having the voltage and amperage defined, supra, and comprising, about a second central switch axis,
- (7.1) a pair of third and fourth fixed contactors;
- (7.2) second fixed mounting means adapted for being mounted on an inside face of one of said opposite handle sidewalls in said handle part and for holding said third and fourth fixed contactors firmly in position relative to said second central switch axis;
- said third and fourths contactors protruding into an interspace between said opposite handle sidewalls and bearing third and fourth contactable regions, respectively, being located in a second planar contact zone;
- (7.3) electrically conductive cord means extending through said handle part and having two ends, said third and fourth fixed contactor means being conductively connected with one end of said cord means;
- said ends of said cord means comprising
- (6.1) a handle cord plug conductively connected with said other end of said cord means, and
- (6.2) lead prongs on said cord plug adapted to be inserted, respectively, into said additional socket throughholes in said cap end wall and to make contact, through said first supporting member, with said contactable terminal regions of said first and second fixed contactors, respectively, while arresting said first supporting member in neutral position;
- said second electrical switch means further comprising
- (7.5) a second supporting member having at least one electrically insulating face extending thereon spaced from, and substantially parallel with, said second planar contact zone;
- (7.6) handle socket throughholes opening out of said handle part and being adapted for receiving therein prongs of an electrical plug of said electrical cable;
- (7.7) at least two shiftable handle contactor elements mounted on said insulating face of said second supporting member, to be electrically insulated from each other,
- each of said handle contactor elements being associated with a different one of said handle socket throughholes to make substantially loss-free contact with connecting plug means of said electrical cable when said plug is inserted into said handle socket throughholes;
- (7.8) second biassing means mounted in said handle part and comprising first and second engagement means adapted for cooperating with each other in biassing said second supporting member toward said second fixed mounting means, and being connected, for pivotal movement relative to each other, with said second supporting member and said second fixed mounting means, respectively;
- said second supporting member comprising actuating means extending to the outside and having a depressable portion protruding to outside said handle when said second supporting member is in neutral position;
- depression of said depressable portion of said actuating means causing said supporting member to pivot about said second central switch axis from its neutral position to an activating position;
- and
- (7.9) second restoring means being in engagement with said second supporting member and said second fixed mounting means, respectively, and being adapted to cause restoring bias applied to said second supporting member when the same is pivoted from its neutral position to an activated position;
- (c) a portable battery adapted for being carried on an operator's person, in combination with battery cable means adapted for being connected to said portable battery, on the one hand, and being adapted to be connected, on the other hand, with one of
- (iii) said two shiftable contactor elements of said first supporting member;
- and
- (iv) said shiftable handle contactor elements of said second supporting member;
- (III) at least one of the following inset units comprising each of the following parts:
- (3) insertable bearing-wall means adapted for being mounted transversely, detachably and in firm position in said open front end of said enveloping shell of said first building block, said insert bearing-wall means having a central axial throughhole and comprising
- (3.1) shaft-bearing means in said axial throughhole;
- (3.2) an insertable power-transmitting intermediary unit comprising
- (3.2.a) insertable shaft means having a forward shaft end and a rearward insertable shaft end, said insertable shaft means being supportable for rotation in said shaft-bearing means engaging a region of said insertable shaft means near said forward shaft end, said rearward shaft end of said insertable shaft means being adapted, upon insertion into said forward chamber of said enveloping shell, for drivingly engaging said driven shaft front end protruding from said first transverse wall into said forward shell chamber;
- (3.2.b) a square-head type connecting piece on said forward end of said insertable shaft means, and being located forward of said shaft-bearing means;
- (3.3) centering socket means adapted for protruding forwardly out of said enveloping shell and being located spaced outwardly from said throughhole;
- and
- (3.4) tool-fastening means adapted for being located outside said enveloping shell and being spaced outwardly from said axial throughhole;
- said insert units being constituted by:
- (8A) an insert unit consisting of the parts defined under (3) through (3.4), supra, per se;
- (8B) an insert unit comprising, besides the parts defined under (3) through (3.4), supra,
- (8.1) fan means mounted on said insertable shaft means in a region thereof, being located in the interior of said forward shell chamber, upon insertion of said unit therein;
- and
- (8.2) vent means provided in said transverse walls of said forward and rearward chambers of said enveloping shell, as well as in said insertable bearing-wall means;
- (8C) an insert unit comprising, besides the parts defined under (3) through (3.4), supra,
- (8.3) an impact-generating unit mounted on said insertable bearing-wall means and on said insertable shaft means;
- (8D) an insert unit comprising, besides the parts defined under (3) through (3.4), supra, a hammer drill mounted on said insertable shaft means;
- all of said insert units fitting with the parts thereof rearward of said bearing-wall means, into said forward chamber of said enveloping shell;
- and said working kit further comprising:
- (IV) at least one of the following tools each of which comprises
- (9) coupling means adapted for firm, detachable and centered coupling of the respective tool with said centering socket means;
- and
- (10) tool operating shaft means comprising a coupling shaft end adapted for being drivingly connected with said square head-type connecting piece at the forward end of said insertable shaft means;
- and is constituted by
- (IV.1) nut-loosening and tightening socket means;
- (IV.2) screw driver means;
- (IV.3) a drilling tool;
- (IV.4) a blade saw tool;
- (IV.5) an angle tool comprising at least one of sander and cutter means.