Electrical connection system for motors

• US 4,523,116 A
• Filed: 03/31/1983
• Issued: 06/11/1985
• Est. Priority Date: 03/31/1983
• Status: Expired due to Term

• Current Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Original Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Inventors: Dibbern, John E. Jr., Moores, Gregory E.
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): Rebsch, D. L.
• Application Number:
  US06/480,781
• Time in Patent Office: 803 Days
• Field of Search: 310/50, 310/71, 310/89, 310/90, 310/47, 310/216, 310/43, 310/230, 310/42, 200/8 R, 200/11 D, 200/11 DA, 200/80 R
• US Class Current: 310/71
• CPC Class Codes: H01H 9/063 enclosing a reversing switch
• CPC Class Codes: H02K 23/66 Structural association with auxiliary electric devices influencing the characteristic of, or controlling, the machine, e.g. with impedances or switches
• CPC Class Codes: H02K 5/225 Terminal boxes or connection arrangements specially adapted for submersible motors H02K5/132

Abstract

Two pairs of contact strips are mounted on the respective bridge members of an integral web portion of the molded field case of a power tool or other motor-driven device. The forward ends of the contact strips are cantilever-mounted and automatically engage the respective terminals on the field, as the field is inserted into the field case and is secured in it. An annular wire harness is mounted on the rear bearing boss of the field case. Spaced contacts are carried by the wire harness and engage the respective ends of the first pair of contact strips. The respective ends of the second pair of contact strips are connected to terminals on the ends of the brush shunts. In a reversing embodiment, a third pair of contact strips is mounted on the bridge, and a rotatable reversing subassembly is mounted on the rear bearing boss in lieu of the wire harness.

Claims

1. In an electric motor having a housing, the housing including a rear portion, an armature rotatably mounted in the housing, a commutator operatively associated with the armature, a pair of brushes engaging the commutator, a field mounted in the housing, the field having a plurality of terminals thereon, the improvement comprising:

the housing further including a main portion receiving the field, the rear portion of the housing including a bearing boss and at least two discrete bridge members joining the bearing boss to the main portion of the housing, the bridge members having respective openings formed therein adjacent to the main portion of the housing, at least one of the bridge members further having an exterior surface and an open channel formed in said exterior surface, first and second contact elements mounted on the rear portion of the housing, each of the contact elements having respective forward and rearward end portions, the respective forward end portions of the contact elements being received through the respective openings in the bridge members, the forward end portions of the contact elements further being connected to respective terminals on the field, first means for connecting the rearward end portion of one of said contact elements to one of the brushes, second means for connecting the rearward end portion of the other of said contact elements to a source of electrical energy, and one of said contact elements being supported in said channel.

4. The improvement of claim 1, wherein:

each of the contact elements having a bent ledge and a tab, and each of the bridge members having a forward end face engaging a respective tab and a rearward end face engaging a respective bent ledge, thereby retaining the contact strips against axial movement relative to the housing.

2. In an electric motor having a housing, the housing including a rear portion, an armature rotatably mounted in the housing, a commutator operatively associated with the armature, a pair of brushes engaging the commutator, a field mounted in the housing, the field having a plurality of terminals thereon, the improvement comprising:

the housing further including a main portion receiving the field, the rear portion of the housing including a bearing boss and at least two bridge members joining the bearing boss to the main portion of the housing the bridge members having respective openings formed therein adjacent to the main portion of the housing, first and second contact elements mounted on the rear portion of the housing, each of the contact elements having respective forward and rearward end portions, the respective forward end portions of the contact elements being received through the respective openings in the bridge members and being connected to respective terminals on the field, each of the contact elements having a bent ledge and a tab, each of the bridge members having a forward end face engaging a respective tab and a rearward end face engaging a respective bent ledge, thereby retaining the contact elements against axial movement relative to the housing, the rearward end portion of the first contact element being spaced radially from the respective bridge member, first means, including a brush shunt, for connecting the rearward end portion of one of said contact elements to one of the brushes, the shunt having an end connected to the rearward end portion of the first contact element, and second means for connecting the rearward end portion of the other of said contact elements to a source of electrical energy.

3. The improvement of claim 2, wherein at least one of the bridge members having a channel formed therein for supporting one of the contact elements.

5. In an electric motor having a housing made from an insulating material, the housing including a rear portion, an armature rotatably mounted in the housing, a commutator operatively associated with the armature, a pair of brushes engaging the commutator, a field mounted in the housing, the field having a plurality of terminals mounted thereon, the improvement comprising:

first and second pairs of contact elements mounted on the rear portion of the housing, each of the contact elements having respective forward and rearward end portions, the forward end portions of the contact elements being connected to respective terminals on the field, first means for connecting the rearward end portions of one of said pairs of contact elements to the respective brushes, second means for connecting the rearward end portions of the other of said pairs of contact elements to a source of electrical energy, the second means including a wire harness having an annular member made from an insulating material, two circumferentially-spaced contacts carried by the wire harness and engaging the respective reaward end portions of said other of said first and second pairs of contact elements, respective conductors connecting the contacts on the wire harness to the source of electrical energy, and mounting means for retaining the annular member on the housing.

8. The improvement of claim 5, wherein the respective rearward end portions of the second pair of contact elements are wedged between the bearing boss and the respective contacts on the annular member.

6. In an electric motor having a housing made from an insulating material, the housing including a rear portion, an armature rotatably mounted in the housing, a commutator operatively associated with the armature, a pair of brushes engaging the commutator, a field mounted in the housing, the field having a plurality of terminals mounted thereon, the improvement comprising:

first and second pairs of contact elements mounted on the rear portion of the housing, each of the contact elements having respective forward and rearward end portions, the forward end portions of the contact elements being connected to respective terminals on the field, first means for connecting the rearward end portions of one of said pairs of contact elements to the respective brushes, second means for connecting the rearward end portions of the other of said pairs of contact elements to a source of electrical energy, the first means including a reversing subassembly, means for rotatably retaining the reversing subassembly on the rear portion of the housing, two arcuately-formed reversing contacts carried by the reversing subassembly, a third pair of contact elements mounted on the rear portion of the housing, the third pair of contact elements having respective forward and rearward end portions, means for connecting the respective forward end portions of the third pair of contact elements to the brushes, and the respective reversing contacts selectively electrically interconnecting respective rearward end portions of one of the third pair of contact elements to the respective rearward end portions of said one of said first and second pairs of contact elements responsive to rotation of said reversing subassembly.

9. The improvement of claim 6, wherein the means for rotatably retaining the reversing subassembly on the rear portion of the housing further precluding substantial axial movement of the reversing subassembly but accomodating a limited rotary movement of the reversing subassembly relative to the housing.

10. The improvement of claim 9, wherein the means for rotatably retaining the reversing subassembly including a resilient member mounted on the reversing subassembly, and a portion of the housing engaging the resilient member.

7. In an electric motor assembly, the combination of a motor housing, a stator subassembly received within the motor housing and secured therein, the stator subassembly having terminal means thereon, contact elements mounted on the motor housing for engaging the terminal means when the stator subassembly is received within the motor housing, said contact elements include first and second portions, an intermediate portion joining the first and second portions and bent transversely thereto, a lanced-out tab formed in the first portion, the tab being disposed in a direction towards the intermediate portion, the second portion being bent tranversely of the first portion and forming an acute angle therewith, and wherein the second portion further terminates in an end section which is bent transversely to the second portion, the end section being substantially parallel to the first portion.

13. The combination of claim 7, wherein the first and second portions terminate in respective ends which are narrower in lateral width than the first and second portions.

11. In an electric motor, the combination of a housing having a rearward portion, the rearward portion including a bearing boss, a stator, means for securing the stator to the rearward portion of the housing, terminal means carried by the stator, a wire harness including an annular member and having means for retaining the annular member on the bearing boss, the wire harness further including spaced contacts and respective conductors connecting the spaced contacts to a source of power, and contact means carried by the rearward portion of the housing for electrically connecting the terminal means on the stator to the contacts on the annular member when the stator is inserted into the housing.

12. In an electric motor, the combination of a field case made from an insulating material, the field case including a web portion having a rear bearing boss and further having a plurality of circumferentially-spaced bridge members, a bearing in the bearing boss, an armature having a shaft journaled in the bearing, a commutator on the shaft, brushes engaging the commutator, a field mounted in the field case, the field having four terminal means connected thereto, a switch for controlling the energization of the motor, an annular member made from an insulating material and retained on the bearing boss, a pair of spaced contacts carried by the annular member, conductor means connecting the contacts with the switch, first means mounted on the web portion of the field case for connecting the contacts with two of the terminal means on the field, and second means mounted on the web portion of the field case for connecting the brushes with the remaining two terminal means on the field.

14. In a reversible electric miotor having a field case, the field case including a web portion having a rear bearing boss, a bearing in the bearing boss, an armature having a shaft journaled in the bearing, a commutator on the shaft, brushes engaging the commutator, a field mounted in the field case, the field having four terminal means connected thereto, and a switch for controlling the energization of the motor, the improvement comprising:

first, second and third pairs of contact elements mounted on the web portion of the field case, each of the pairs of contact elements having respective forward and rearward end portions, the forward end portions of the first and second pairs of contact elements being connected to the respective terminal means on the field, means for connecting the forward end portions of the third pair of contact elements with the respective brushes, means for connecting the rearward end portions of the first pair of contact elements to the switch, and reversing means for selectively electrically interconnecting the respective rearward end portions of the second and third pairs of contact elements to change the direction of rotation of the armature.

15. The improvement of claim 14, wherein the reversing means comprising:

an outer annular member, a reversing actuator formed on the outer annular member and projecting radially therefrom, an inner annular member received within the outer annular member, and the inner annular member carrying the reversing contacts.

16. The improvement of claim 14, wherein the reversing contacts each include an arcuate band having longitudinally-split forward contact portions.

17. A drive system, comprising:

a housing, a reversible electric motor having an armature shaft rotatably connected to the housing, an output shaft connected for rotation in a predetermined direction to the armature shaft through a transmission normally having a predetermined "N" number of drive elements, a reversing switch operatively associated with the armature shaft and moveable from a first position to a second position to cause said output shaft to rotate in said predetermined direction, and compensating means operatively associated with said reversing switch, depending on whether "N" is even or odd, for enabling the output shaft to rotate in said predetermined direction responsive to movement of said reversing switch from said first position to said second position, when said transmission has either more than or less than said "N" number of drive elements.

18. The drive system of claim 17, wherein:

the armature shaft mounting a commutator, the motor further including a field, and the compensating means including contact means for electrically connecting said field to said commutator, the contact means being selectively locatable on said switch relative to said first and second switch positions.

19. In a power tool, the combination of an insulating field case having a web portion provided with a rear bearing boss, a bearing in the boss, an armature having a shaft journaled in the bearing, a commutator carried by the shaft, a pair of brushes engaging the commutator, respective shunts on the brushes, respective terminals on the ends of the shunts, a field subassembly retained in the field case and having a pair of field coils, each of the field coils having a pair of leads, four terminals carried by the field subassembly and insulated therefrom, the leads of the field coils being connected to the terminals, first, second and third pairs of bent contact strips mounted on the web portion of the field case, each contact strip having respective forward and rearward ends, the terminals on the field subassembly receiving the forward ends of the first and second pair of contact strips and being connected thereto, respectively, the respective terminals on the brush shunts being connected to the forward ends of the third pair of contact strips, a reversing member, means for retaining the reversing member on the bearing boss and accommodating a limited rotary movement thereon, whereby the reversing member has at least two alternate positions, a pair of spaced arcuate contacts carried by the reversing member, means for reversibly connecting the rearward ends of the second and third pair of contact strips to the spaced contacts on the reversing member, respectively, in the two alternate positions of the reversing member, a switch in the tool, and means for connecting the switch to the rearward ends of the first pair of contact strips.

20. The combination of claim 19, wherein the reversing member has an upwardly-projecting portion provided with an opening to receive the boss, the upwardly-projecting portion terminating in a reversing button, and further comprising a rear handle cover connected to the boss and having an aperture with a surrounding dwell to receive the reversing button.

21. In a power tool having a housing made from an insulating material, the combination of a stator means inserted within the housing and secured therein, terminal means on the stator means, contact elements radially spaced from an axis and mounted within the housing and further engaging the terminal means, an arcuate reversing member made from an insulating material, means mounting the reversing member for limited rotary movement about the axis on the housing adjacent the contact elements, whereby the reversing member has two alternate positions, the reversing member having a manually-manipulatable portion projecting through the housing, a switch in the tool, interlocking means between the switch and the reversing member, means for connecting two of the contact elements to the switch, and means including respective contact means on the reversing member for reversibly connecting the remaining contact elements to each other in the respective alternate positions of the reversing member.

22. In an electric motor, the subcombination of a field case from an insulating material, the field case including a main portion and further including a web portion, the web portion including a plurality of discrete circumferentially-spaced bridge members, each of the bridge members having an opening formed therein substantially adjacent to the main portion of the field case, contact elements received in the respective openings in the bridge members and retained therein, each of the contact elements having respective cantilevered forward portions, some of the contact elements having respective cantilevered rearward portions, the remaining contact elements having downwardly-bent rearward portions, and the respective bridge members for the remaining contact elements having respective exterior surfaces and open channels formed therein for receiving the respective downwardly-bent rearward portions of the remaining contact elements.

23. In an electric motor, the subcombination of a field case made from an insulating material, the field case including a main portion and further including an integral web portion, the web portion including a plurality of discrete, circumferentially-spaced bridge members having respective exterior surfaces and open channels formed therein, each of the bridge members having an opening formed therein substantially adjacent to the main portion of the field case, each of the bridge members having a forward face and a rearward face adjacent to the respective opening therein, and a plurality of contact strips received within the respective channels and openings in the bridge members, each of the contact strips having a bent ledge portion engaging the rearward face of its respective bridge member, and each of the contact strips further having a tab engaging the forward face of its respective bridge member, whereby each contact strip may be inserted into its respective opening in the bridge member and retained therein.

24. A housing for a dynamoelectric machine, comprising:

a plurality of cantilever-mounted contact elements extending axially from said housing, and radially spaced from an axis, an arcuate switch member rotatably mounted on the housing about said axis and adjacent said contact elements, and having contact means for selectively engaging said contact elements, said contact means including at least one contact member formed with a bifurcated end, and means operatively associated with said contact means and said switch member for compensating for tolerance build-up associated with differences in radial distances of respective contact elements from said axis.