US3655019A - Electrostatic device with controllable acceleration - Google Patents

Electrostatic device with controllable acceleration Download PDF

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Publication number
US3655019A
US3655019A US91956A US3655019DA US3655019A US 3655019 A US3655019 A US 3655019A US 91956 A US91956 A US 91956A US 3655019D A US3655019D A US 3655019DA US 3655019 A US3655019 A US 3655019A
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US
United States
Prior art keywords
drum
band
drums
energize
rotated
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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 - Lifetime
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US91956A
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English (en)
Inventor
Theodore T Trzaska
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NCR Voyix Corp
National Cash Register Co
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NCR Corp
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Publication date
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    • 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
    • B41J9/00—Hammer-impression mechanisms
    • B41J9/26—Means for operating hammers to effect impression
    • B41J9/40—Means for operating hammers to effect impression including an electro-adhesive clutch
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02N—ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR
    • H02N13/00—Clutches or holding devices using electrostatic attraction, e.g. using Johnson-Rahbek effect

Definitions

  • An electrically conductive band contacts a portion of the peripheries of the drums; the [52] U.S. Cl ..192/48.9, 192/80, 192/84E peripheries of the drums are coated with semi-conductor P- F164! F 164 27/12 material.
  • One end of the band is connected to a tensioning Field of Search t 34 E device, and the other end is connected to a utilization device (like a print hammer).
  • Electrostatic clutches or devices utilize electro-adhesion; i. e., a mutual attraction between a semi-conductor (which is usually placed on the periphery of a rotating drum) and a conductor (which is usually an electrically conducting band wrapped around a portion of the drum).
  • the electrostatic device of the present invention provides for a more controlled and accurate acceleration.
  • the drums and their associated electrically conducting band to operate within more ideal loads. For example, when the band is to be accelerated positively, the first drum is rotated at a lower constant velocity than the second drum. The first drum is energized to transfer its motion to the band, and then the second drum is energized" while the first drum is simultaneously deenergized. Because the first drum is rotating at a lower velocity, the first drum and the band coact within a more ideal friction range to get the band accelerated from a rest position.
  • the second drum is energized to further accelerate the band to the desired terminal velocity with a minimum of slippage, thereby providing a more accurately controlled acceleration. While this invention is generally described as employing positive acceleration, it should be apparent that this technique can be used in devices which utilize negative acceleration as in electrostatic braking devices.
  • the device has:
  • This invention relates to an electrostatic device which utilizes the Johnson-Rahbek effect.
  • the device includes at least first and second drums, which are rotated at constant but substantially different velocities.
  • the drums are coated with a semi-conductor material, and an electrically conducting band contacts a portion of the peripheries of the drums.
  • One end of the band is connected to a tensioning device, and the other end is connected to a utilization device.
  • a controlled acceleration of the band is obtained.
  • Several drums and several bands may be used. Both positive and negative accelerations of the band may be utilized, depending upon the particular application of the device of this invention. Selective energization of the bands to be driven is also obtainable.
  • FIG. 1 is a general perspective view of an electrostatic device embodying the principles of this invention. Several drums with semi-conductor material on their peripheries are shown with an electrically conducting band engaging portions of the peripheries of the drums. The output of the device, for example, may be used to actuate a print hammer.
  • FIG. 2 is an energization diagram showing the sequence of energizing the various drums used.
  • FIG. 3 is a diagram showing the displacement of the band with respect to time as each of the drums is energized.
  • FIG. 4 is a perspective view similar to FIG. 1, showing a portion of a second embodiment, which permits selective energization of the bands operating from a common set of drums.
  • FIG. I is a general perspective view of the electrostatic device of this invention, which is designated generally as 10.
  • the device 10 includes at least two drums, A, B, and C, which are supported on shafts for rotation by conventional drive means shown only diagrammatically as 12, 14, and 16, respectively.
  • Each of the drums A, B, and C has a conventional semiconductor coating 18 on its periphery, as is done with devices utilizing the Johnson-Rahbek effect.
  • Various examples of coatings are disclosed in the U.S. patents cited earlier in this application.
  • Each of the drums is rotated at a constant velocity but at substantially different speeds.
  • the drums A, B, and C may be respectively rotated at 100, 200, and 300 revolutions per minute. While the drums are shown as having equal diameters, they could naturally be of different diameters if the specific requirements of a particular situation dictated it.
  • an electrically conducting band is wrapped around a portion of the periphery of the drum; however, in the device 10 (FIG. 1) an electrically conducting band 20 engages the peripheries of the drums A, B, and C, as shown.
  • One end of the band 20 is connected to an electrically grounded tensioning device (like a spring 22), and the remaining end is connected to a utilization device, which, for illustrative purposes, is shown as a print hammer lever 24.
  • the band 20 is wrapped around a portion of the periphery of the drum A, and around portions of the peripheries of the drums B and C. While the drums A, B, and C are shown as rotating on axes in spaced parallel relationship, which axes lie in a common plane, they need not lie in the same plane. The amount of surface contact desired between the band 20 and the particular drum helps determine the location of the drums relative to one another.
  • the width of the band is all factors to be considered in the design for a specific application. Because these particular design considerations may be conventional, they are not reviewed herein in detail.
  • each of the drums A, B, and C (FIG. 1) has its own slip ring 26, 28, and 30, respectively, by which the coating 18 on the corresponding drum is energized.
  • An energizing means 32 is used to sequentially energize the drums A, B, and C.
  • the energizing means 32 utilizes conventional drum and then energizing the second drum while simultaneelectronic circuitry to energize the drums A, B, and C as follows.
  • the spring 22 provides the normal tension and electrical ground potential on the band 20, which is normally in slipping engagement with the drums.
  • the first drum A is energized by placing an electrical potential on its coating 18 via a conductor 34 from the energizing means 32 and the slip ring 26, causing the band to be attracted to the drum A. Because the drum A rotates clockwise (as viewed in FIG. 1), the motion of the drum A will be imparted to the band.
  • the timing chart showing the energization of the drums A, B, and C is shown in FIG. 2, and the band displacement is shown in FIG. 3.
  • the point 36 on FIG. 3 represents the start of the energization of the drum A.
  • the drum B will be energized via a conductor 38 from energizing means 32 and the slip ring 28, causing the band 20 to be attracted to the drum B. Because the drum B rotates counter-clockwise, the motion of the drum B will be imparted to the band 20 to add to the velocity of the band imparted by the drum A.
  • the drum A is simultaneously deenergized, as shown by the timing chart in FIG. 2.
  • FIG. 3 represents the start of the energization of the drum B and the deenergization of the drum A.
  • the drum C will be energized via a conductor 42 from the energizing means 32 and the slip ring 30, causing the band 20 to be attracted to the drum C. Because the drum C rotates clockwise, the motion of the drum C will be imparted to the band 20 to add to the velocity of the band imparted by the drums B and A.
  • the drum B is simultaneously deenergized, as shown by the timing chart in FIG. 2.
  • the point 44 on FIG. 3 represents the start of the energization of the drum C and the deenergization of the drum B.
  • the band 20 After a fixed time interval, the band 20 will be accelerated to the desired terminal velocity (i. e., the peripheral velocity of the drum C), represented by the point 46 on FIG. 3, and the drum C will be deenergized.
  • the desired terminal velocity i. e., the peripheral velocity of the drum C
  • the drum C will be deenergized.
  • the fixed time interval of energization of each of the drums A, B, and C was 1 millisecond; however, the actual time interval selected is, of course, dependent upon the particular application of the device 10 and the design factors relating to band width, speed and diameter of the drums, and
  • the band 20 may be accelerated more smoothly and be controlled more accurately than can be done through using one drum alone to obtain a desired terminal velocity of the band.
  • the process just described is somewhat analogous to the shifting of gears in an automobile to accelerate it to a desired terminal velocity. While the device 10 has been described as accelerating the band 20 to a positive terminal velocity, the device 10 may also be used to decelerate the band and thereby use the device as an electrostatic brake.
  • the first drum to be energized is the one whose speed is highest relative to the other two drums when three drums are used.
  • the drum which is closest to the end of the band which is to be decelerated would have a peripheral velocity which is in the same direction as the moving band, but the actual velocity of the periphery of the drum contacting the band would be less than the velocity of the moving band, thereby decelerating the moving band when the drum is energized.
  • the remaining drums would successively further brake the band toward zero velocity.
  • the device 50 shown in FIG. 4 may be used.
  • the device 50 is substantially the same as the device 10 shown in FIG. 1 except that means are shown for selectively energizing the bands to be accelerated.
  • Elements in FIG. 4 which are identical to those shown in FIG. I bear the same reference characters, and a portion of the device 50 is omitted to simplify the drawing, as this omitted portion is identical to FIG. 1.
  • the electrically conducting bands 20 and 48 have one of their ends connected to springs 22, which are supported by a support 52, made of electrically insulating material so as to isolate one band from the other.
  • a control circuit 54 would be used to select the particular band to be energized, thereby actuating a particular print hammer lever, like 24 in FIG. 1.
  • the control circuit may be conventional and, in effect, merely grounds the particular band selected to be energized over its output conductors 56 and 58 connected to the bands 20 and 48, respectively.
  • the control circuit 54 grounds the band 48 over the conductor 58 and simultaneously actuates the energizing means 32 over the conductor 60.
  • the energizing means 32 then sequentially energizes the drums A, B, and C, as previously described in relation to FIGS. 2 and 3.
  • the grounded conductor like 58, is opened by the control circuit 54, the next band selected for energization is grounded, and the energizing process described is repeated.
  • An electrostatic device utilizing the Johnson-Rahbek” effect comprising:
  • At least first and second drums having axes of rotation in spaced, parallel relationship, and having peripheries coated with semi-conductor material
  • first and second drive means for rotating said first and second drums respectively at a constant rotational velocity
  • said first and second drums being dimensioned so as to produce substantially different peripheral speeds in cooperation with said first and second drive means respectively; at least one electrically conducting band being wrapped around a portion of the periphery of the first drum and around a portion of the periphery of the second drum so as to contact the semi-conductor material thereon; said band having first and second ends with the first end being connected to a tensioning device and the second end being connected to a utilization device; and energizing means to energize the first drum to attract the band thereto to impart the motion of the first drum to the band, and to simultaneously deenergize the first drum and energize the second drum to attract the band thereto to impart the motion of the second drum to the band, the motion imparted to the band by the first and second drums being cumulative and in the same direction.
  • the electrostatic device as claimed in claim 1 in which the second drum is rotated in a direction opposite to the direction of the first drum, and in which the second drum is rotated at a higher speed than the first drum.
  • the electrostatic device as claimed in claim 1 further including a third drum having its periphery coated with semiconductor material and third drive means for rotating said third drum at a constant rotational velocity;
  • first, second, and third drums being identical in size and having their axes of rotation lying in a common plane;
  • said second drum being rotated in a direction which is opposite to the direction of said first and third drums; and said second drum being rotated at a substantially higher speed than said first drum, and said third drum being rotated at a substantially higher speed than said second drum;
  • said band also being wrapped around a portion of the periphery of the third drum
  • said energizing means being adapted to energize the third drum after the second drum is energized and to simultaneouslyrdeenergize the second drum upon the energization of the third drum.
  • the electrostatic device as claimed in claim 3 further comprising at least a second electrically conducting band being wrapped around portions of said first, second, and third drums to operate in a manner identical to that of said firstnamed band.
  • drums being so dimensioned as to produce substantially different peripheral speeds in cooperation with said drive means, with said drums being arranged in a sequence so that the first drum in the sequence has a first peripheral speed and each succeeding drum in the sequence has a substantially higher peripheral speed than the preceding drum;
  • each said band having a first end and a second end
  • control means for selecting the band to be energized; and energizing means to energize the first drum to attract the

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  • Paper Feeding For Electrophotography (AREA)
  • General Electrical Machinery Utilizing Piezoelectricity, Electrostriction Or Magnetostriction (AREA)
US91956A 1970-11-23 1970-11-23 Electrostatic device with controllable acceleration Expired - Lifetime US3655019A (en)

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US9195670A 1970-11-23 1970-11-23

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US (1) US3655019A (es)
JP (1) JPS5124655B1 (es)
AU (1) AU452585B2 (es)
BE (1) BE775699A (es)
CA (1) CA925917A (es)
CH (1) CH539975A (es)
DE (1) DE2157700A1 (es)
ES (1) ES397185A1 (es)
FR (1) FR2115313B1 (es)
GB (1) GB1313820A (es)
IT (1) IT941764B (es)
ZA (1) ZA717347B (es)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0028707A1 (en) * 1979-11-05 1981-05-20 International Business Machines Corporation Electrostatic clutch
US4393967A (en) * 1979-11-05 1983-07-19 International Business Machines Corporation Electrostatic clutch
US4393769A (en) * 1980-12-31 1983-07-19 International Business Machines Corporation Electrostatic clutch-operated printing mechanism

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6216662U (es) * 1985-07-16 1987-01-31

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2850907A (en) * 1956-08-03 1958-09-09 Powers Samas Account Mach Ltd Motion transmitters
US2850908A (en) * 1957-03-06 1958-09-09 Powers Samas Account Mach Ltd Motion transmitters
US2916920A (en) * 1957-03-11 1959-12-15 Powers Samas Account Mach Ltd Motion transmitters

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2850907A (en) * 1956-08-03 1958-09-09 Powers Samas Account Mach Ltd Motion transmitters
US2850908A (en) * 1957-03-06 1958-09-09 Powers Samas Account Mach Ltd Motion transmitters
US2916920A (en) * 1957-03-11 1959-12-15 Powers Samas Account Mach Ltd Motion transmitters

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0028707A1 (en) * 1979-11-05 1981-05-20 International Business Machines Corporation Electrostatic clutch
US4393967A (en) * 1979-11-05 1983-07-19 International Business Machines Corporation Electrostatic clutch
US4393769A (en) * 1980-12-31 1983-07-19 International Business Machines Corporation Electrostatic clutch-operated printing mechanism

Also Published As

Publication number Publication date
CH539975A (de) 1973-07-31
BE775699A (fr) 1972-03-16
AU3543871A (en) 1973-05-17
FR2115313A1 (es) 1972-07-07
AU452585B2 (en) 1974-09-05
JPS5124655B1 (es) 1976-07-26
CA925917A (en) 1973-05-08
IT941764B (it) 1973-03-10
ES397185A1 (es) 1975-03-16
ZA717347B (en) 1972-07-26
GB1313820A (en) 1973-04-18
DE2157700A1 (es) 1972-05-31
FR2115313B1 (es) 1973-06-29

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