US3639789A - Insulated armature construction and method - Google Patents

Insulated armature construction and method Download PDF

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US3639789A
US3639789A US878825A US3639789DA US3639789A US 3639789 A US3639789 A US 3639789A US 878825 A US878825 A US 878825A US 3639789D A US3639789D A US 3639789DA US 3639789 A US3639789 A US 3639789A
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sleeve
armature
shaft
laminations
rotor
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US878825A
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Thaddeus E Bednarski
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Black and Decker Corp
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Black and Decker Manufacturing Co
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K15/00—Methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines
    • H02K15/02—Methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines of stator or rotor bodies
    • H02K15/024—Methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines of stator or rotor bodies with slots
    • H02K15/028—Methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines of stator or rotor bodies with slots for fastening to casing or support, respectively to shaft or hub
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K1/00—Details of the magnetic circuit
    • H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
    • H02K1/22—Rotating parts of the magnetic circuit
    • H02K1/28—Means for mounting or fastening rotating magnetic parts on to, or to, the rotor structures
    • H02K1/30—Means for mounting or fastening rotating magnetic parts on to, or to, the rotor structures using intermediate parts, e.g. spiders

Definitions

  • Murphy ABSTRACT An armature including a sleeve of insulating material bonded in place between the armature shaft and the armature laminations.
  • the insulating sleeve may extend under the commutator if desired.
  • a method of providing this annature is also described which comprises holding the laminations, the sleeve and the shaft in their relative positions and injecting a bonding material between the sleeve and the shaft and between the sleeve and the laminations.
  • This invention relates to double insulated armature shafts and is particularly directed to a double insulated construction which is both improved and less expensive to manufacture.
  • One present method of providing insulation between the shaft of an electric motor and the stack of laminations in which the armature windings are placed is based on the injection and molding in place of a material which performs both the functions of bonding the laminations to the shaft and of insulating the laminations from the shaft. It is ⁇ difficult to obtain materials which adequately meet all of the requirements of this process without excessive cost. An even more significant expense of this process is the fact that the material must be molded in place within a highly complex press which holds the various elements in the proper location and applies suitable heat and pressure so that an injected resin is molded in place. Suitable presses for perfonning this operation are extremely expensive; in addition, only a few units can be processed at a time so that, for mass production, large numbers of the presses are required with a consequent increase in the capital investment required.
  • Another object of this invention is the provision of a new and improved armature which is less susceptible to breakdown of the insulation between the armature shaft and the laminations.
  • Another object of this invention is the provision of a new and improved method of constructing armatures which is less complicated and less expensive than previous methods.
  • an armature for an electric motor which includes a rotor having a plurality of windings and a central bore, a shaft located within the bore for providing a power output, an insulating sleeve disposed between the rotor and the shaft and adhesive layers respectively affixing the rotor to the sleeve and the sleeve to the shaft.
  • the sleeve comprises a glass cylinder and the adhesive layers are of sufficient thickness to compensate for thermal and mechanical stresses between the rotor and the sleeve and between the sleeve and the shaft.
  • the sleeve may comprise a paper cylinder.
  • FIG. 1 is a plan view, partially in cross section, of an annature constructed in accord with the present invention.
  • FIG. 2 is a cross-sectional view of apparatus for performing the method in accord with this invention.
  • an armature I which comprises a stack of laminations 11 having a plurality of slots 12 in which coils 13 of insulated wire are wound in accord with conventional practice. Each coil is attached to a conductive bar 14 of a commutator 15, the particular armature illustrated being designed for use in a universal motor.
  • the laminations 11 are provided with a central bore 16 in which is disposed a shaft 17.
  • an electromagnetic torque applied to the windings causes the rotor to rotate and a power output is derived from one end of the shaft 17 which is located within the bore 16.
  • the shaft is insulated from the rotor stack by means of a sleeve 18 of insulating material which surrounds the shaft and extends under the entire length of the stack.
  • the sleeve is affixed to the shaft 17 and to the stack 11 by means of adhesive layers 19 and 20.
  • the sleeve 18 comprises a glass cylinder while the adhesive layers comprise a room temperature vulcanizing silicon rubber.
  • FIG. 2 illustrates schematically a suitable fixture for the performance of the method of this invention.
  • the supporting structure 21 includes respective openings 22, 23 and 24 for receiving the shaft, sleeve and laminations.
  • a cover member 25 is clamped in place to secure the laminations and to hold the shaft and sleeve in alignment.
  • Vacuum lines 26 are preferably used to prevent the entrapping of air at the base of the unit; appropriate means may of course be provided to seal off these openings when the adhesive is introduced.
  • the adhesive is supplied from a reservoir of liquid adhesive.
  • a valve 27 supplies the adhesive to nozzles 28 and 29 which respectively inject the liquid adhesive into the spaces between the laminations and the sleeve and between the sleeve and the shaft.
  • curing may be performed either by time alone or by the application of heat to increase the speed of curing.
  • the fixture and tooling for performing this method are much simpler than that required by previous methods.
  • the tolerance'requirements for the relative size and position of the three elements need only be maintained within several thousandths of an inch. Although this is still a relatively small space, the difference in the tooling required to maintain this tolerance as compared to that of less than 0.001 inch may reduce the cost by a factor of one-third to one-fifth.
  • a similar comparison also applies when considering this equipment as compared to'that required for performing molding of a material which must function both as an adhesive and as an insulator.
  • the subject invention not only enables the cost of manufacture to be substantially reduced, but it also provides a more effective insulative barrier than previous methods. Specifically, if the single layer of previous constructions is provided, a breakdown in that material which occurs due to a particular cause is frequently of a type which can readily propagate across the width of the material. This is due to the fact that the cause of the initial breakdown may continue to affect the-same material in the same way. In a construction according to the present invention, however, this possibility is avoided because there are two different material arranged in three layers between the shaft and the stack. Thus, a cause of failure in one of the layers is unlikely to have any effect at all on the adjacent layer of the other material.
  • the insulation provided by the illustrated construction is substantially more effective than that provided by previous constructions.
  • the adhesive material is a room temperature vulcanizing rubber.
  • This particular embodiment is of interest due t'othe fact that the dielectric strength of glass is so highthat the insulation requirements such as, for example, those of- Underwriters Laboratories, Inc., are more than fulfilled by the glass cylinder itselfand any insulating effect provided by the rubber is, in effect, a bonus.
  • a potential difficulty with this embodiment is the possibility that the glass may break.
  • this is overcome by providing a sufficiently thick and sufficiently resilient layer of adhesive on each side of the sleeve'so that any stresses introduced between the shaft and the stack which might tend to fracture the glass are taken up by the adhesive. For example, these stresses may be either thermal, due to a difference in the amount of expansion under heat of the glass cylinder as compared to the metal stack and shaft, or mechanical, due to the twisting moment between therotor stack and the shaft.
  • the'sleeve is made of paper of a sufficient thickness and dielectric strength so that the electrical insulative requirements are met.
  • the adhesive need only be sufficient to bond the elements together.
  • the sleeve can be positioned rather loosely around the shaft and the adhesive can be injected under sufficient pressure to insure that all of the spaces in both annular openings selected if desired. it is also noted that, to meet specific requirements, various modifications in the properties of these materials may be desired.
  • a certain amount of resilience in the adhesive material may be provided to relieve strain which would otherwise break the gears in the output of the tool or other device in which the motor is used.
  • the sleeve may be paper or cardboard of sufficient thickness to provide the required dielectric strength.
  • the adhesive layers need only be sufficientto insure bonding of the three elements of the structure together.
  • other insulative materials may be sleeve in the construction of this invention be a continuous cylindrical body. While it is possible toprovide multiple elements which, when placed together approximate a cylinder, this introduces difficulty in aligning the pieces and therefore increases the cost and complexity of manufacture.
  • the adhesive- may not adequately fill the interface between the pieces and, even if it does, "it permits the possibility of propogation of a fault through one material, thus defeating a particularly desirable feature of this. invention.
  • An armature for an electric motor comprising a rotor having a plurality of windings and a central bore;
  • a second adhesive layer disposed between said sleeve and said shaft to afiix said sleeve to said shaft.

Abstract

An armature including a sleeve of insulating material bonded in place between the armature shaft and the armature laminations. The insulating sleeve may extend under the commutator if desired. A method of providing this armature is also described which comprises holding the laminations, the sleeve and the shaft in their relative positions and injecting a bonding material between the sleeve and the shaft and between the sleeve and the laminations.

Description

United States Patent Bednarski [54] INSULATED ARMATURE CONSTRUCTION AND METHOD [72] inventor: Thaddeus E. Bednarski, Timonium, Md.
[73] Assignee: The Black and Decker Manufacturing Company, Towson, Md.
221 Filed: Nov.2l,1969
211 Appl.No.: 878,825
[52] U.S. Cl ..310/43, 310/261 [51] Int. Cl. ..H02k 1/04 [58] Field of Search ..310/42, 43, 47, 50, 265, 216,
[56] References Cited UNITED STATES PATENTS 2,541,047 2/1951 Frisbie et a1. ..310/235 2,818,517 12/1957 Loosjes ..310l26l X 3,447,011 5/1969 Amrein et a1. .....310/236 X 3,471,731 10/1969 Pratt et al. ..310/235 X 1 1 Feb. 1, 1972 FOREIGN PATENTS OR APPLICATIONS 979,009 1/1965 Great Britain ..3 10/43 Primary Examiner-D. F. Duggan Attorney-Leonard Bloom, Joseph R. Slotnik and Edward D. Murphy ABSTRACT An armature including a sleeve of insulating material bonded in place between the armature shaft and the armature laminations. The insulating sleeve may extend under the commutator if desired. A method of providing this annature is also described which comprises holding the laminations, the sleeve and the shaft in their relative positions and injecting a bonding material between the sleeve and the shaft and between the sleeve and the laminations.
8 Claims, 2 Drawing Figures PATENTEDFEB H972 3.639.789
PRESSURIZED ADHESIVE I mvmon THADDEUS E. BEDNARSKI TO VACUUM SYSTEM 26 24 BY My ATTORNEY INSULATED ARMATURE CONSTRUCTION AND METHOD This invention relates to double insulated armature shafts and is particularly directed to a double insulated construction which is both improved and less expensive to manufacture.
One present method of providing insulation between the shaft of an electric motor and the stack of laminations in which the armature windings are placed is based on the injection and molding in place of a material which performs both the functions of bonding the laminations to the shaft and of insulating the laminations from the shaft. It is \difficult to obtain materials which adequately meet all of the requirements of this process without excessive cost. An even more significant expense of this process is the fact that the material must be molded in place within a highly complex press which holds the various elements in the proper location and applies suitable heat and pressure so that an injected resin is molded in place. Suitable presses for perfonning this operation are extremely expensive; in addition, only a few units can be processed at a time so that, for mass production, large numbers of the presses are required with a consequent increase in the capital investment required.
An alternative to this method is that of molding a sleeve around the armature shaft, grinding it to an appropriate size and pressing it into the center bore in the stack of laminations. While this process decreases the expense of the press required for molding the sleeve, the tolerance requirements of the pressing operation are extremely high. These requirements apply to the size of the center bore, the size of the molded sleeve and the relative position of the sleeve and the stack as the pressing is performed. Tolerance limitations on these steps are usually on the order of 0.001 inch or even less. Massproduction tooling which can maintain these tolerances over extended periods of quality production is extremely expensive. It is a primary purpose of this invention toprovide a new armature construction which avoids these difficulties and the consequent expense while at the same time providing improved results.
It is accordingly an object of this invention to provide a new and improved insulated armature.
Another object of this invention is the provision of a new and improved armature which is less susceptible to breakdown of the insulation between the armature shaft and the laminations.
Another object of this invention is the provision of a new and improved method of constructing armatures which is less complicated and less expensive than previous methods.
Further objects and advantages of this invention will become apparent as the description and illustration thereof ensue.
Briefly, in accord with one embodiment of this invention, an armature for an electric motor is provided which includes a rotor having a plurality of windings and a central bore, a shaft located within the bore for providing a power output, an insulating sleeve disposed between the rotor and the shaft and adhesive layers respectively affixing the rotor to the sleeve and the sleeve to the shaft. In a particular embodiment, the sleeve comprises a glass cylinder and the adhesive layers are of sufficient thickness to compensate for thermal and mechanical stresses between the rotor and the sleeve and between the sleeve and the shaft. In accord with another specific embodiment, the sleeve may comprise a paper cylinder.
This invention will thus be understood from a consideration of the following description and accompanying drawings in which:
FIG. 1 is a plan view, partially in cross section, of an annature constructed in accord with the present invention; and
FIG. 2 is a cross-sectional view of apparatus for performing the method in accord with this invention.
In FIG. 1, an armature I is illustrated which comprises a stack of laminations 11 having a plurality of slots 12 in which coils 13 of insulated wire are wound in accord with conventional practice. Each coil is attached to a conductive bar 14 of a commutator 15, the particular armature illustrated being designed for use in a universal motor.
The laminations 11 are provided with a central bore 16 in which is disposed a shaft 17. In use, an electromagnetic torque applied to the windings causes the rotor to rotate and a power output is derived from one end of the shaft 17 which is located within the bore 16.
In accord with the present invention, the shaft is insulated from the rotor stack by means of a sleeve 18 of insulating material which surrounds the shaft and extends under the entire length of the stack. The sleeve is affixed to the shaft 17 and to the stack 11 by means of adhesive layers 19 and 20. For example, in a preferred embodiment of this invention, the sleeve 18 comprises a glass cylinder while the adhesive layers comprise a room temperature vulcanizing silicon rubber.
A particularly significant advantage of this invention is derived from the method of assembly. Specifically, as previously noted, other methods require very complex and expensive equipment, either for holding the parts in place during molding or for meeting the tolerance requirements of a pressing operation. The armature of the present invention can be constructed in simple, inexpensive apparatus which can readily be adapted to the manufacture of large quantities. For example, FIG. 2 illustrates schematically a suitable fixture for the performance of the method of this invention. The supporting structure 21 includes respective openings 22, 23 and 24 for receiving the shaft, sleeve and laminations. A cover member 25 is clamped in place to secure the laminations and to hold the shaft and sleeve in alignment. Vacuum lines 26 are preferably used to prevent the entrapping of air at the base of the unit; appropriate means may of course be provided to seal off these openings when the adhesive is introduced.
The adhesive is supplied from a reservoir of liquid adhesive. A valve 27 supplies the adhesive to nozzles 28 and 29 which respectively inject the liquid adhesive into the spaces between the laminations and the sleeve and between the sleeve and the shaft. After the adhesive is introduced, curing may be performed either by time alone or by the application of heat to increase the speed of curing.
Even if a source of heat is provided to assist in curing the adhesive, the fixture and tooling for performing this method are much simpler than that required by previous methods. For example, the tolerance'requirements for the relative size and position of the three elements need only be maintained within several thousandths of an inch. Although this is still a relatively small space, the difference in the tooling required to maintain this tolerance as compared to that of less than 0.001 inch may reduce the cost by a factor of one-third to one-fifth. A similar comparison also applies when considering this equipment as compared to'that required for performing molding of a material which must function both as an adhesive and as an insulator.
As previously noted, the subject invention not only enables the cost of manufacture to be substantially reduced, but it also provides a more effective insulative barrier than previous methods. Specifically, if the single layer of previous constructions is provided, a breakdown in that material which occurs due to a particular cause is frequently of a type which can readily propagate across the width of the material. This is due to the fact that the cause of the initial breakdown may continue to affect the-same material in the same way. In a construction according to the present invention, however, this possibility is avoided because there are two different material arranged in three layers between the shaft and the stack. Thus, a cause of failure in one of the layers is unlikely to have any effect at all on the adjacent layer of the other material. For example, if breakdown of the polymeric adhesive material occurs due to age in either of the adhesive layers, it may propagate rapidly across the width of that layer but it will not propagate through the sleeve since the sleeve is chemically different and is not affected by the same conditions. On the other hand, if a rupture occurs in the sleeve, it will not affect the adhesive layers on either side since the adhesive is a relatively resilient material and will withstand the rupturing stress. Thus, the insulation provided by the illustrated construction is substantially more effective than that provided by previous constructions.
' and the adhesive material is a room temperature vulcanizing rubber. This particular embodiment is of interest due t'othe fact that the dielectric strength of glass is so highthat the insulation requirements such as, for example, those of- Underwriters Laboratories, Inc., are more than fulfilled by the glass cylinder itselfand any insulating effect provided by the rubber is, in effect, a bonus. A potential difficulty with this embodiment is the possibility that the glass may break. In accord with this invention, this is overcome by providing a sufficiently thick and sufficiently resilient layer of adhesive on each side of the sleeve'so that any stresses introduced between the shaft and the stack which might tend to fracture the glass are taken up by the adhesive. For example, these stresses may be either thermal, due to a difference in the amount of expansion under heat of the glass cylinder as compared to the metal stack and shaft, or mechanical, due to the twisting moment between therotor stack and the shaft.
Another embodiment of this invention which also enjoys the advantages listed above is that in which the'sleeve is made of paper of a sufficient thickness and dielectric strength so that the electrical insulative requirements are met. In this embodiment, since the sleeveis not susceptible to breaking, even wider tolerance in manufacture can be permitted since the adhesive need only be sufficient to bond the elements together. Thus, the sleeve can be positioned rather loosely around the shaft and the adhesive can be injected under sufficient pressure to insure that all of the spaces in both annular openings selected if desired. it is also noted that, to meet specific requirements, various modifications in the properties of these materials may be desired. For example, by providing a certain amount of resilience in the adhesive material, a certain amount of relative rotation may be permitted between the stack and the shaft under locked-rotor condition. This may be used to relieve strain which would otherwise break the gears in the output of the tool or other device in which the motor is used. I
in another embodiment, the sleeve may be paper or cardboard of sufficient thickness to provide the required dielectric strength. In this case, the adhesive layers need only be sufficientto insure bonding of the three elements of the structure together.
Regardless of the material selected, it is preferred that the are filled. Of course, other insulative materials may be sleeve in the construction of this invention be a continuous cylindrical body. While it is possible toprovide multiple elements which, when placed together approximate a cylinder, this introduces difficulty in aligning the pieces and therefore increases the cost and complexity of manufacture. In addition, the adhesive-may not adequately fill the interface between the pieces and, even if it does, "it permits the possibility of propogation of a fault through one material, thus defeating a particularly desirable feature of this. invention.
While several embodiments of .this invention have been shown and described, it will be apparent to those skilled in the art that many changes and modifications may be made from the specific illustrations without departing from the spirit of this invention in its broader aspects as defined by the appended claims.
lclaimz- 1. An armature for an electric motor comprising a rotor having a plurality of windings and a central bore;
a shaft located within said bore;
an insulating sleeve disposed between said rotor and said shaft;
a first adhesive layer disposed between said rotor and said sleeve to affix rotor to said sleeve; and
a second adhesive layer disposed between said sleeve and said shaft to afiix said sleeve to said shaft.
2. An armature as claimed in claim 1 wherein said sleeve comprises a continuous cylinder of insulating material.
3.. An armature as claimed in claim 2 wherein said sleeve alone has sufficient dielectric strength to insulate said shaft from said windings. l
4. An armature as claimed in claim 1 and including a stack 5. An armature as claimed in claim 4 wherein said sleeve comprises a continuous cylinder of insulating material.
6. An armature as claimed in claim 1 wherein said adhesive layers are sufficiently flexible to protect said sleeve from stress fracture.
7. An armature as claimed in claim 6 wherein said sleeve is glass.
8. An armature as claimed in claim 1 wherein said sleeve is paper.
\ UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Pate t 3 ,789 February 1 1972 Dated Thaddeus E. Bednarski Inventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
AT COLUMN 4, LINE 23, BETWEEN "AI-"FIX" AND "Roma", SAID SHOULD BE INSERTED.
Signed and sealed this 17th day of October 1972.
(SEAL) Attest:
EDWARD M. PLETCHER,JR ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents Patent No. 3,639,789 Dated February 1, 1972 Thaddeus E. Bednarski Inventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby v corrected as shown below:
AT COLUMN 4, LINE 23, scrwzm "AFFlx" AND "ROTOR", SAID SHOULD BE I NSERTED.
Signed and sealed this 17th day of October 1972.?
(SEAL) Attest:
EDWARD M. PLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents

Claims (8)

1. An armature for an electric motor comprising a rotor having a plurality of windings and a central bore; a shaft located within said bore; an insulating sleeve disposed between said rotor and said shaft; a first adhesive layer disposed between said rotor and said sleeve to affix rotor to said sleeve; and a second adhesive layer disposed between said sleeve and said shaft to affix said sleeve to said shaft.
2. An armature as claimed in claim 1 wherein said sleeve comprises a continuous cylinder of insulating material.
3. An armature as claimed in claim 2 wherein said sleeve alone has sufficient dielectric strength to insulate said shaft from said windings.
4. An armature as claimed in claim 1 and including a stack of laminations between said sleeve and said windings, said windings being mounted on said laminations; and wherein said sleeve is at least as long as said stack.
5. An armature as claimed in claim 4 wherein said sleeve comprises a continuous cylinder of insulating material.
6. An armature as claimed in claim 1 wherein said adhesive layers are sufficiently flexible to protect said sleeve from stress fracture.
7. An armature as claimed in claim 6 wherein said sleeve is glass.
8. An armature as claimed in claim 1 wherein said sleeve is paper.
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Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3766416A (en) * 1971-05-15 1973-10-16 Papst Motoren Kg Internally insulated, metal enclosed electric motor
US4791328A (en) * 1985-12-06 1988-12-13 Fasco Industries, Inc. Multi-piece rotor for dynamoelectric machine
US6300704B1 (en) * 1998-05-28 2001-10-09 Robert Bosch Gmbh Rotor for an electric motor and process for manufacturing the rotor
US20040144652A1 (en) * 2002-12-12 2004-07-29 Syozo Kasai Capillary array apparatus, method of manufacturing the same, and electrophoresis analysis method
US11384719B2 (en) 2019-03-15 2022-07-12 Milwaukee Electric Tool Corporation Fluid tank for a power tool
US11518018B2 (en) 2019-01-21 2022-12-06 Milwaukee Electric Tool Corporation Power tool with non-conductive driveshaft
US11618149B2 (en) 2019-04-26 2023-04-04 Milwaukee Electric Tool Corporation Telescoping tool with collapsible bearing assembly

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1793986A (en) * 1928-06-14 1931-02-24 Vincent G Apple Dynamo-electric-machine armature
US2541047A (en) * 1945-08-21 1951-02-13 Gilbert Co A C Fractureproofed frangible body and production thereof
US2818517A (en) * 1953-10-29 1957-12-31 Philips Corp Method of securing a member to a shaft
GB979009A (en) * 1962-10-18 1965-01-01 Hevent Developments Ltd Improvements in or relating to glandless motor driven circulating pumps
US3413498A (en) * 1965-08-09 1968-11-26 Rockwell Mfg Co Electrically powered hand tool
US3447011A (en) * 1966-10-31 1969-05-27 Black & Decker Mfg Co Armature construction for double-insulated tool
US3471731A (en) * 1967-06-13 1969-10-07 Millers Falls Co Armature
US3476960A (en) * 1968-07-01 1969-11-04 Singer Co Double insulated power tools
US3477125A (en) * 1967-07-20 1969-11-11 Robbins & Myers Method of making a double insulated armature

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1793986A (en) * 1928-06-14 1931-02-24 Vincent G Apple Dynamo-electric-machine armature
US2541047A (en) * 1945-08-21 1951-02-13 Gilbert Co A C Fractureproofed frangible body and production thereof
US2818517A (en) * 1953-10-29 1957-12-31 Philips Corp Method of securing a member to a shaft
GB979009A (en) * 1962-10-18 1965-01-01 Hevent Developments Ltd Improvements in or relating to glandless motor driven circulating pumps
US3413498A (en) * 1965-08-09 1968-11-26 Rockwell Mfg Co Electrically powered hand tool
US3447011A (en) * 1966-10-31 1969-05-27 Black & Decker Mfg Co Armature construction for double-insulated tool
US3471731A (en) * 1967-06-13 1969-10-07 Millers Falls Co Armature
US3477125A (en) * 1967-07-20 1969-11-11 Robbins & Myers Method of making a double insulated armature
US3476960A (en) * 1968-07-01 1969-11-04 Singer Co Double insulated power tools

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3766416A (en) * 1971-05-15 1973-10-16 Papst Motoren Kg Internally insulated, metal enclosed electric motor
US4791328A (en) * 1985-12-06 1988-12-13 Fasco Industries, Inc. Multi-piece rotor for dynamoelectric machine
US6300704B1 (en) * 1998-05-28 2001-10-09 Robert Bosch Gmbh Rotor for an electric motor and process for manufacturing the rotor
US20040144652A1 (en) * 2002-12-12 2004-07-29 Syozo Kasai Capillary array apparatus, method of manufacturing the same, and electrophoresis analysis method
US7422672B2 (en) * 2002-12-12 2008-09-09 Hitachi High-Technologies Corporation Capillary array apparatus, method of manufacturing the same, and electrophoresis analysis method
US20080302665A1 (en) * 2002-12-12 2008-12-11 Syozo Kasai Capillary array apparatus, method of manufacturing the same, and electrophoresis analysis method
US11518018B2 (en) 2019-01-21 2022-12-06 Milwaukee Electric Tool Corporation Power tool with non-conductive driveshaft
US11904452B2 (en) 2019-01-21 2024-02-20 Milwaukee Electric Tool Corporation Power tool with non-conductive driveshaft
US11384719B2 (en) 2019-03-15 2022-07-12 Milwaukee Electric Tool Corporation Fluid tank for a power tool
US11618149B2 (en) 2019-04-26 2023-04-04 Milwaukee Electric Tool Corporation Telescoping tool with collapsible bearing assembly

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