CA1067566A - Electromagnet - Google Patents
ElectromagnetInfo
- Publication number
- CA1067566A CA1067566A CA247,121A CA247121A CA1067566A CA 1067566 A CA1067566 A CA 1067566A CA 247121 A CA247121 A CA 247121A CA 1067566 A CA1067566 A CA 1067566A
- Authority
- CA
- Canada
- Prior art keywords
- pole
- shoes
- armature
- electromagnet
- coil
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F7/00—Magnets
- H01F7/06—Electromagnets; Actuators including electromagnets
- H01F7/08—Electromagnets; Actuators including electromagnets with armatures
- H01F7/16—Rectilinearly-movable armatures
- H01F7/1607—Armatures entering the winding
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
- B41J2/22—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of impact or pressure on a printing material or impression-transfer material
- B41J2/23—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of impact or pressure on a printing material or impression-transfer material using print wires
- B41J2/27—Actuators for print wires
- B41J2/285—Actuators for print wires of plunger type
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F7/00—Magnets
- H01F7/06—Electromagnets; Actuators including electromagnets
- H01F7/08—Electromagnets; Actuators including electromagnets with armatures
- H01F7/081—Magnetic constructions
- H01F2007/085—Yoke or polar piece between coil bobbin and armature having a gap, e.g. filled with nonmagnetic material
Abstract
ABSTRACT:
An electromagnet comprising two cylindrical pole-shoes which are coaxially arranged one in the pro-longation of the other and which are magnetically separat-ed from each other by a magnetically non-conductive inter-mediate ring. Around the pole-shoes an electrical excita-tion coil is arranged for moving an armature which is slidable in the pole-shoes. Pole-shoes, intermediate ring and coil are integrally interconnected by a connect-ing member of synthetic material. The armature can be connected, for example, to a recording pin of a printing device. As a result of the use of the connecting member of synthetic material, the number of operations required for assembling the electromagnet is reduced.
An electromagnet comprising two cylindrical pole-shoes which are coaxially arranged one in the pro-longation of the other and which are magnetically separat-ed from each other by a magnetically non-conductive inter-mediate ring. Around the pole-shoes an electrical excita-tion coil is arranged for moving an armature which is slidable in the pole-shoes. Pole-shoes, intermediate ring and coil are integrally interconnected by a connect-ing member of synthetic material. The armature can be connected, for example, to a recording pin of a printing device. As a result of the use of the connecting member of synthetic material, the number of operations required for assembling the electromagnet is reduced.
Description
~0~7S66 The invention relates to an electromagnet comprising two cylindri-cal pole-shoes which are coaxially arranged end to end and which are made of a magnetically conductive material, the pole-shoes being magnetically separated from each other by an intermediate ring, a cylindrical armature which is displaceable against the force of a spring being slidable in the said pole-shoes when a coil arranged about the pole-shoes is energi7ed.
In a known electromagnet of the kind set forth (German Offenlegungs- ;
schrift 2.119.415) which is used in a printing device, the pole-shoes, the intermediate ring and the electrical excitation coil are connected to the upper side and the lower side of a cylindrical housing by means of a clamping construction. The clamping action is obtained by means of a construction consisting of nuts, bolts and flanges.
The known electromagnet has a drawback in that its assembly requires a comparatively large number of operations.
The invention has for its object to provide an electromagnet which -.~ requires fewer assembly operations. -According to the present invention, then, there is provided an electromagnet comprising two magnetically conductive pole-shoes coaxially -arranged end to end; an intermediate ring magnetically separating one of said pole-shoes from the other; a cylindrical armature slidably mounted within said pole-shoes, said armature being actuatable in one direction by energization of a coil arranged axially about said pole-shoes inter-mediate ring; and a reset spring mounted within said pole-shoes adjacent to the armature, said spring being compressed upon actuation of the armature, wherein the pole-shoes, intermediate ring and coil are inter-connected by a connecting member, composed of a suitab]e plastic material, i the connecting member being situated between said pole-shoes and the coil.
Electromagnets in accordance with the invention are particularly suitable for use in printing devices of the type where a character to ~, 30 be printed is composed of a number of dots. Printing devices of this -kind are generally referred to as matrix printers. The printing member ... .
~ - 2 - ~
10675~;6 of these printing devices is formed by a wire-like recording pin which is driven by an electromagnet.
An electromagnet in accordance with the invention which is parti-cularly suitable for matrix printers is characterized in that a recording pin is connected to the armature.
The invention will be described in detail hereinafter with reference to the drawing.
Figure 1 is a longitudinal sectional view of a preferred embodiment of an electromagnet for a matrix printer in accordance with the invention, Figure 2 is partly a side elevation and partly a longitudinal sectional view at an increased scale of an armature of the electromagnet shown in Figure 1.
Figure 3 is a front view of the armature shown in Figure 2.
The electromagnet for a matrix printer shown in Figure 1 comprises two cylindrical pole-shoes 1 and 3 which are coaxially arranged one in the prolongation of the other and which are made of a suitably magnetically conductive material. The inner diameter of the pole-shoes 1 and 3 are equal in a preferred embodiment. The pole-shoes 1 and 3 are physically and magnetically separated from each other by an intermediate ring 5 of a magnetically non-conductive material such as, for example, brass. By way of a cylindrical member 7 composed of thermoplastic synthetic matorial, the pole-shoes 1 and 3 and the intermediate rlng 5 are connected to an electri-cal excitation coil 9 which is coaxial with the pole-shoes 1 and 3.
Consequently, the connecting member 7 not only serves as a connecting mem-ber but also as a coil-former. In the pole-shoes 1 and 3 a cylindrical armature 11 is slidably arranged. When the coil 9 is energized, the arma-ture 11 is displaced downwards against the force of a helical reset spring 13. The upper end of the reset spring 13 bears against the armature 11 and its lower end bears against a rigid cylindrical support 15 on the pole-shoe 3.
~ :
` - 3 -,,.
` ~0675~6 The armature 11 includes a support body made of a synthetic material and comprising a cylindrical central portion 17 and two cylindrical flanges 19 and 21. The diameter of the central portion 17 is smaller than that of the two cylindrical flanges 19 and 21, so that a space remains between the support body of synthetic material on the one hand and the pole-shoes 1 and intermediate ring 5 on the other hand. This space accommodates a hollow axial cylinder 23 composed of a suitably magnetically conductive material. The outer diameter of the cylinder 23 is slightly smaller than the inner diameter of the pole-shoes 1 and 3 and the intermediate ring 5.
Because the outer diameter of the flanges 19 and 21 substantially equals the inner diameter of the pole-shoes and the intermediate ring, only the outer circumference of the flanges 19 and 21 serves as a guide surface for ~ -~
the armature 11.
Because the armature 11 is partly made of a synthetic material, a ; saving is realized as regards weight as well as regards the comparatively expensive magnetic material. Moreover, the friction on the armature is re-duced.
In the non-energized condition of the coil 9, the armature 11 is lightly biased by the reset spring 13 against a cylindrical abutment 25 which is rigidly provided in the pole-shoe 1.
A wire shaped recording pin 27 is connected to armature 11 by means of a holder 29. The holdcr 29 ls rigidly connectod to thc recording pin ` 27. On the lower side of the flange 21 there is provided a flexible edge 31 which serves to locate the holder 29 by allowing th~ holder to be snapped into placo. Around the holder 29 there is provided a grommet l 33 for supporting the reset spring 13. The holder 29 is preferably made Z of brass, whilst the gromme~ 33 is preferably made of a synthetic material.
An elastic connection between armature and recording pin, having a damping .
~ ~:
t~
.
. 10675~6 PHD. 75-033.
19-2-1976.
effect, is thus realized.
The pole-shoes 1 and 3 are provided with cir-cumferential grooves 35 and 37, respectively, which have a rectangular section and ~hich serve to anchor the con-necting member 7. The connecting member 7 is cast or mould-ed after the pole-shoes 1 and 3 and the intermediate ring 5 have been arranged on a mandril in the correct position relative to each other. A casting die or mould is arrang-; ed around this assembly on the mandril. The pre-manufactured coil may form part of this mould. It is alternatively pos-sible~ however, to wlnd the coil on the connecting member ; 7 only after the moulding or casting has been completad.
The thermoplastic material for the connecting member 7 is pre~erably a fibreglass-reinforced polycarbonate or poly-amide. Even though thermoplastic synthetic materia~s are preferably used for the connecting member, thermosetting materials are also feasible.
The synthetio part o~ the armature 11 i9 pro-~erably made of polymer isate~ notably copolymerlsates or homopolymerisates. In order to reduce the ~rictlon between the armature and the pole-shoes and the inter~e-diate ring~ polytetrafluoroethylene is preferably added .. . . .
I to the said polymerisates.
As appears from the Figs. 2 and 3, the armature 11 can be provided with longitudinal grooves 41. The frict-ion caused by particles which have become detached from the armature and the pole-shoes is reduced by these groo~es, R
... ~ .
~67S~i6 PHD. 75-33.
19-2-1976.
.- ',' because these particles collect therein.
Even though the invention has been described with reference to an electromagnet for a printing device, the invention is by no means restricted thereto. The arma-ture can inter alia co-operate with hinge arms, levers etc., for example, for driving a step mechanism in a counting device, The armature of an electromagnet in accordance with the invention can be embodied in various ways. For example, the entire armature can be made of a magnetically conductive material.
'., ' :, .
.
,' ;' , ' ~
.
`'', .~ ' ' ~"'~
:~ .
:
:- - - . .
. .
In a known electromagnet of the kind set forth (German Offenlegungs- ;
schrift 2.119.415) which is used in a printing device, the pole-shoes, the intermediate ring and the electrical excitation coil are connected to the upper side and the lower side of a cylindrical housing by means of a clamping construction. The clamping action is obtained by means of a construction consisting of nuts, bolts and flanges.
The known electromagnet has a drawback in that its assembly requires a comparatively large number of operations.
The invention has for its object to provide an electromagnet which -.~ requires fewer assembly operations. -According to the present invention, then, there is provided an electromagnet comprising two magnetically conductive pole-shoes coaxially -arranged end to end; an intermediate ring magnetically separating one of said pole-shoes from the other; a cylindrical armature slidably mounted within said pole-shoes, said armature being actuatable in one direction by energization of a coil arranged axially about said pole-shoes inter-mediate ring; and a reset spring mounted within said pole-shoes adjacent to the armature, said spring being compressed upon actuation of the armature, wherein the pole-shoes, intermediate ring and coil are inter-connected by a connecting member, composed of a suitab]e plastic material, i the connecting member being situated between said pole-shoes and the coil.
Electromagnets in accordance with the invention are particularly suitable for use in printing devices of the type where a character to ~, 30 be printed is composed of a number of dots. Printing devices of this -kind are generally referred to as matrix printers. The printing member ... .
~ - 2 - ~
10675~;6 of these printing devices is formed by a wire-like recording pin which is driven by an electromagnet.
An electromagnet in accordance with the invention which is parti-cularly suitable for matrix printers is characterized in that a recording pin is connected to the armature.
The invention will be described in detail hereinafter with reference to the drawing.
Figure 1 is a longitudinal sectional view of a preferred embodiment of an electromagnet for a matrix printer in accordance with the invention, Figure 2 is partly a side elevation and partly a longitudinal sectional view at an increased scale of an armature of the electromagnet shown in Figure 1.
Figure 3 is a front view of the armature shown in Figure 2.
The electromagnet for a matrix printer shown in Figure 1 comprises two cylindrical pole-shoes 1 and 3 which are coaxially arranged one in the prolongation of the other and which are made of a suitably magnetically conductive material. The inner diameter of the pole-shoes 1 and 3 are equal in a preferred embodiment. The pole-shoes 1 and 3 are physically and magnetically separated from each other by an intermediate ring 5 of a magnetically non-conductive material such as, for example, brass. By way of a cylindrical member 7 composed of thermoplastic synthetic matorial, the pole-shoes 1 and 3 and the intermediate rlng 5 are connected to an electri-cal excitation coil 9 which is coaxial with the pole-shoes 1 and 3.
Consequently, the connecting member 7 not only serves as a connecting mem-ber but also as a coil-former. In the pole-shoes 1 and 3 a cylindrical armature 11 is slidably arranged. When the coil 9 is energized, the arma-ture 11 is displaced downwards against the force of a helical reset spring 13. The upper end of the reset spring 13 bears against the armature 11 and its lower end bears against a rigid cylindrical support 15 on the pole-shoe 3.
~ :
` - 3 -,,.
` ~0675~6 The armature 11 includes a support body made of a synthetic material and comprising a cylindrical central portion 17 and two cylindrical flanges 19 and 21. The diameter of the central portion 17 is smaller than that of the two cylindrical flanges 19 and 21, so that a space remains between the support body of synthetic material on the one hand and the pole-shoes 1 and intermediate ring 5 on the other hand. This space accommodates a hollow axial cylinder 23 composed of a suitably magnetically conductive material. The outer diameter of the cylinder 23 is slightly smaller than the inner diameter of the pole-shoes 1 and 3 and the intermediate ring 5.
Because the outer diameter of the flanges 19 and 21 substantially equals the inner diameter of the pole-shoes and the intermediate ring, only the outer circumference of the flanges 19 and 21 serves as a guide surface for ~ -~
the armature 11.
Because the armature 11 is partly made of a synthetic material, a ; saving is realized as regards weight as well as regards the comparatively expensive magnetic material. Moreover, the friction on the armature is re-duced.
In the non-energized condition of the coil 9, the armature 11 is lightly biased by the reset spring 13 against a cylindrical abutment 25 which is rigidly provided in the pole-shoe 1.
A wire shaped recording pin 27 is connected to armature 11 by means of a holder 29. The holdcr 29 ls rigidly connectod to thc recording pin ` 27. On the lower side of the flange 21 there is provided a flexible edge 31 which serves to locate the holder 29 by allowing th~ holder to be snapped into placo. Around the holder 29 there is provided a grommet l 33 for supporting the reset spring 13. The holder 29 is preferably made Z of brass, whilst the gromme~ 33 is preferably made of a synthetic material.
An elastic connection between armature and recording pin, having a damping .
~ ~:
t~
.
. 10675~6 PHD. 75-033.
19-2-1976.
effect, is thus realized.
The pole-shoes 1 and 3 are provided with cir-cumferential grooves 35 and 37, respectively, which have a rectangular section and ~hich serve to anchor the con-necting member 7. The connecting member 7 is cast or mould-ed after the pole-shoes 1 and 3 and the intermediate ring 5 have been arranged on a mandril in the correct position relative to each other. A casting die or mould is arrang-; ed around this assembly on the mandril. The pre-manufactured coil may form part of this mould. It is alternatively pos-sible~ however, to wlnd the coil on the connecting member ; 7 only after the moulding or casting has been completad.
The thermoplastic material for the connecting member 7 is pre~erably a fibreglass-reinforced polycarbonate or poly-amide. Even though thermoplastic synthetic materia~s are preferably used for the connecting member, thermosetting materials are also feasible.
The synthetio part o~ the armature 11 i9 pro-~erably made of polymer isate~ notably copolymerlsates or homopolymerisates. In order to reduce the ~rictlon between the armature and the pole-shoes and the inter~e-diate ring~ polytetrafluoroethylene is preferably added .. . . .
I to the said polymerisates.
As appears from the Figs. 2 and 3, the armature 11 can be provided with longitudinal grooves 41. The frict-ion caused by particles which have become detached from the armature and the pole-shoes is reduced by these groo~es, R
... ~ .
~67S~i6 PHD. 75-33.
19-2-1976.
.- ',' because these particles collect therein.
Even though the invention has been described with reference to an electromagnet for a printing device, the invention is by no means restricted thereto. The arma-ture can inter alia co-operate with hinge arms, levers etc., for example, for driving a step mechanism in a counting device, The armature of an electromagnet in accordance with the invention can be embodied in various ways. For example, the entire armature can be made of a magnetically conductive material.
'., ' :, .
.
,' ;' , ' ~
.
`'', .~ ' ' ~"'~
:~ .
:
:- - - . .
. .
Claims (5)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An electromagnet comprising two magnetically conductive pole-shoes coaxially arranged end to end; an intermediate ring magnetically separating one of said pole-shoes from the other; a cylindrical armature slidably mounted within said pole-shoes, said armature being actuatable in one direction by energization of a coil arranged axially about said pole-shoes and intermediate ring; and a reset spring mounted within said pole-shoes adjacent to the armature, said spring being compressed upon actuation of the armature, wherein the pole-shoes, intermediate ring and coil are interconnected by a connecting member, composed of a suitable plastics material, the connecting member being situated between said pole-shoes and the coil.
2. An electromagnet as claimed in Claim 1, in which the connecting member is made of a thermoplastic material.
3. An electromagnet as claimed in Claim 1 or 2, in which the pole-shoes are provided with circumferential grooves in which the material of the connecting member is anchored.
4. An electromagnet as claimed in Claim 1 in which a recording pin is connected to the armature.
5. An electromagnet as claimed in Claim 4, in which the armature comprises a cylindrical support made of a suitable plastics material, said support comprising an annular recessed portion accommodating a hollow annular cylinder of magnetically conductive material which has an outer diameter which is smaller than the outer diameter of the cylindrical support.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2509917A DE2509917C3 (en) | 1975-03-07 | 1975-03-07 | Electromagnet |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1067566A true CA1067566A (en) | 1979-12-04 |
Family
ID=5940696
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA247,121A Expired CA1067566A (en) | 1975-03-07 | 1976-03-04 | Electromagnet |
Country Status (8)
| Country | Link |
|---|---|
| JP (1) | JPS51113160A (en) |
| CA (1) | CA1067566A (en) |
| DE (1) | DE2509917C3 (en) |
| FR (1) | FR2303360A1 (en) |
| GB (1) | GB1481297A (en) |
| IT (1) | IT1074453B (en) |
| NL (1) | NL167539C (en) |
| SE (1) | SE404737B (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4137513A (en) * | 1977-10-27 | 1979-01-30 | Ncr Corporation | Matrix print wire solenoid |
| JPS5488549U (en) * | 1977-12-06 | 1979-06-22 | ||
| EP0217969A1 (en) * | 1985-09-28 | 1987-04-15 | Mannesmann Tally Ges. mbH | Plunger-type core for frequencies up to 3,000 Hz and more |
| DE3627648A1 (en) * | 1986-08-14 | 1988-02-18 | Philips Patentverwaltung | DC MAGNET |
| GB2218572B (en) * | 1988-05-09 | 1991-08-07 | Lay Soo Chang | Electronically operated baby cradle rocking apparatus |
| DE19727414A1 (en) * | 1997-06-27 | 1999-01-07 | Bosch Gmbh Robert | Method of manufacturing a solenoid for a valve and valve with a solenoid |
| GB2335796B (en) * | 1998-03-12 | 2002-04-10 | Poramaste Jinupun | Variable reluctance solenoid |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1972124U (en) * | 1967-08-11 | 1967-11-09 | Binder Magnete K G | ACTIVATION MAGNET. |
| JPS557930B2 (en) * | 1972-07-07 | 1980-02-29 |
-
1975
- 1975-03-07 DE DE2509917A patent/DE2509917C3/en not_active Expired
-
1976
- 1976-02-26 SE SE7602427A patent/SE404737B/en unknown
- 1976-03-03 NL NL7602174.A patent/NL167539C/en not_active IP Right Cessation
- 1976-03-04 IT IT48416/76A patent/IT1074453B/en active
- 1976-03-04 GB GB8691/76A patent/GB1481297A/en not_active Expired
- 1976-03-04 CA CA247,121A patent/CA1067566A/en not_active Expired
- 1976-03-05 JP JP51023381A patent/JPS51113160A/en active Pending
- 1976-03-05 FR FR7606333A patent/FR2303360A1/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| DE2509917A1 (en) | 1976-09-09 |
| IT1074453B (en) | 1985-04-20 |
| DE2509917B2 (en) | 1978-02-23 |
| SE404737B (en) | 1978-10-23 |
| JPS51113160A (en) | 1976-10-06 |
| FR2303360B1 (en) | 1981-09-04 |
| NL7602174A (en) | 1976-09-09 |
| GB1481297A (en) | 1977-07-27 |
| SE7602427L (en) | 1976-09-08 |
| FR2303360A1 (en) | 1976-10-01 |
| NL167539B (en) | 1981-07-16 |
| DE2509917C3 (en) | 1978-10-26 |
| NL167539C (en) | 1981-12-16 |
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