US3608337A - Locking device - Google Patents

Locking device Download PDF

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Publication number
US3608337A
US3608337A US871892A US3608337DA US3608337A US 3608337 A US3608337 A US 3608337A US 871892 A US871892 A US 871892A US 3608337D A US3608337D A US 3608337DA US 3608337 A US3608337 A US 3608337A
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United States
Prior art keywords
circuit
inclusive
wash
braking
door
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 - Lifetime
Application number
US871892A
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English (en)
Inventor
Robert Neville Redfearn
Harry Dawson Watkin
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.)
Fisher Bendix Ltd
Original Assignee
Fisher Bendix Ltd
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Filing date
Publication date
Priority claimed from GB00363/69A external-priority patent/GB1243376A/en
Application filed by Fisher Bendix Ltd filed Critical Fisher Bendix Ltd
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Publication of US3608337A publication Critical patent/US3608337A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16P—SAFETY DEVICES IN GENERAL; SAFETY DEVICES FOR PRESSES
    • F16P3/00—Safety devices acting in conjunction with the control or operation of a machine; Control arrangements requiring the simultaneous use of two or more parts of the body
    • F16P3/08—Safety devices acting in conjunction with the control or operation of a machine; Control arrangements requiring the simultaneous use of two or more parts of the body in connection with the locking of doors, covers, guards, or like members giving access to moving machine parts
    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
    • D06F37/00—Details specific to washing machines covered by groups D06F21/00 - D06F25/00
    • D06F37/42—Safety arrangements, e.g. for stopping rotation of the receptacle upon opening of the casing door

Definitions

  • This invention is for improvements in or relating to cabinets or casings housing electrically driven machinery and especially locking means for the doors thereof.
  • the invention is particularly although not exclusively concerned with a locking means for the door of a washing machine.
  • a washing machine is a typical example, the rotating machinery being in this case a cylinder or drum which is rotated at high speed particularly during the final or dying stage of the clothes washing programme. Following this final stage the washed articles have to be removed and it is important that it should not be possible to open the door of the machine to do this until the speed of rotation of the cylinder or drum has fallen to a safe limit.
  • a cabinet or casing for electrically driven machinery having a door, a lock for said door, an electrically energised device for retaining said lock in its door locking state and means for causing an electric driving motor for said machinery to operate temporarily as a generator when it is switched off and to supply electric current to said device for retaining the lock in its door locking state whereby the door cannot be opened until the speed of said machinery has fallen to a safe limit.
  • the electrically energised device of the door lock will, in the usual way, be maintained in its door locking state by an electricity supply from the mains during normal operation of the machine.
  • the electric driving motor can operate temporarily as a generator for maintaining a supply of current to the door locking device until eventually the speed of rotation of the motor and therefore of the washing cylinder drum has fallen to a safe limit at which time the device will become de-energised and permit the door to be opened.
  • a load resistor can be included in the motor circuitry when it is temporarily switched to operate as a generator for regenerative braking and for the supply of maintaining current temporarily to the door locking device.
  • This load resistance may be an electric heating element or elements of the washing machine.
  • the machine is of the kind comprising a cabinet within which there is a tub housing a cylinder or drum which is rotated by an electric motor at a higher speed particularly during the rinsing and/or drying period of the washing cycle.
  • a wide variation of drum speeds can now be achieved by using a thyristor controlled direct current series motor.
  • the cabinet is provided with a glass-fronted door for the introduction of the clothes, to be washed into the cylinder or drum and their subsequent removal therefrom.
  • the door has an interlock device which is held in its locking position by a solenoid connected to the supply so as to be energised so long as current is supplied to the driving motor for the drum.
  • Regenerative braking of the drum or cylinder at the end of the washing programme is achieved by shunting the field and the armature of the motor, disconnecting the supply from the control thyristor and running the motor as a generator using, initially, the residual magnetism of the field.
  • the solenoid coil of the door interlock can be connected in parallel with a brake load resistor. Sufficient voltage is available across this resistor to keep the solenoid coil energised, after switching off the machine, until the drum speed has fallen to something of the oder of 50 revolutions per minute. At this speed the solenoid coil is de-energised (i.e. there is not sufiicient voltage across the resistor to keep it energised), and the door of the cabinet can then be opened by which time it will be safe to remove the clothes from the drum or cylinder.
  • FIG. 1 shows a tapped field, reversing armature, load resistor braking arrangement
  • FIG. 2 shows a tapped field, reversing armature, load resistor braking arrangement in which a water heating element of the washing machine is also utilised as the load resistor during regenerative braking,
  • FIG. 3 shows an untapped field, reversing field, load resistor braking arrangement
  • FIG. 4 shows an untapped field, reversing armature, load resistance braking arrangement in which a Water heating element of the washing machine is utilised as the load resistor,
  • FIG. 5 shows a tapped field, reversing field, load resistor braking arrangement
  • FIG. 6 shows a tapped field, reversing field, load resistor braking arrangement in which a water heating element of the washing machine is utilised as the load resistor, and
  • FIG. 7 illustrates a modification wherein the control signal is applied over two lines neither of which are elfectively earthed.
  • An armature A and a field winding S4 of a drum drive direct current series-connected motor are connected in series through interconnections across two terminals T2 and T3 of a control C1 which also has a neutral connection T1.
  • the interconnections include a forward-reverse switch S1, a wash spin speed selector S2 (in FIGS. 1 to 6 only) and a normal-braking switch S3.
  • the switch S3 is actuated by a no-volt relay C2 connected between line potential wire L and neutral terminal T1.
  • a door latch solenoid C3 for operating a door lock is normally connected in parallel with the relay C2 and there is a braking resistor S (which can be a water heating element)-
  • the door latch solenoid can be designed to have a W pull-off force (the pull on force can be high but this is unimportant).
  • terminal T2 is at earth potential but in FIG. 7 terminals T2 and T3 are fed by a rectifier bridge inside the control C1 and neither are effectively earthed in normal running.
  • the use of a bridge gives greater flexibility of control and enables the speed selectors S2 to be dispensed with.
  • the load resistor S5 is a Water heater element provided basically for heatin the washing water in the machine. In normal running this is connected to the neutral terminal T3 and to the line potential wire L through co-operating contacts 38, 39 connected together by a float or other water level sensor so that the element is not energised in the absence of water and through co-operating controls 36, 37 operated by a programme device. During braking these contacts 36, 37 and 38, 39 are by-passed.
  • circuits and switches are best described by the circuit diagrams and relating the various functional configurations provided by the switches.
  • the reference numerals on the drawings are to identify the various routes to the armature A on operation of the switches.
  • the forward-reverse switch S1 is in a position F
  • the wash/spin selector S2 is in position W
  • the brake relay switch S3 in a position N.
  • the circuit is from T3 to 1, 2, 4 to 21 inclusive and to T2.
  • the circuit is from T3 to 1, 2, 4, 5, 22, 23, 18, to 7 inclusive 24, 20, 21 and to T2.
  • the wash/spin selector changes to position S. This allows the reversing switch to be by-passed.
  • the braking relay contacts remain at N.
  • the circuit is from T3 to 1, 2, 3, 25, 9 to 16 inclusive 26, 21 and to T2.
  • the relay For braking the relay is de-energised and the contacts changed to B.
  • the wash/spin selector remains at S.
  • the armature-field shunt circuit is then from T3 to 1, 2, 4, 5, 22, 28, 14 to 11 inclusive 27, 34, 33, 32, 1 and to T3.
  • the placing of the door-interlock solenoid coil in parallel with the braking resistor is by 34, 31, 29, 39, 40, 41, 38 and T1 to T3 inside the control C1.
  • the reversing switch is in position F, the wash/spin selector is in position W and the relay contacts are in position N.
  • the circuit is then from T3 to 1, 3, 4, to 20 inclusive and to T2.
  • the reversing switch is in position R.
  • the circuit is then from T3, to 1, 3, 4, 21, 22, 17, to 6 inclusive, 23, 19, 20, and to T2.
  • the Wash/spin selector is in position S.
  • the circuit is then from T3 to 1, 2, 24, 8 to 15 inclusive, 25, and to T2.
  • the wash/spin selector is at S and the brake relay contacts are in position B.
  • the armature-field shunt circuit is then from T3 to 1, 3, 4, 21, 27, 13, 12, 11, 10, 26, 31, 32, 33, 34, 35 to T1 and inside control C1 to T3.
  • the interlock solenoid parallel circuit with heating element is from 31 to 28, 45, 46, 47 to N and inside control C1 to T3.
  • the reversing switch is in position R.
  • the circuit is then from T3 to 1 to 4 inclusive, 21, 22, 23, 17 and 6 inclusive, 24, 19, 20 and to T2.
  • the wash/spin selector is in position S and the relay contacts are in position N.
  • the circuit is then from T3 to 1 to 4 inclusive 21, 25, 8 to 15 inclusive, 26, 20 and to T2.
  • the wash/spin selector is at S and the relay contacts are in position B.
  • the armature-fiield shunt circuit is then from T3 to 1-4 inclusive, 21, 22, 28, 12 to 10 inclusive, 27, 32, 33, 34, 1 and to T3.
  • the interlock solenoid parallel circuit with braking resistor is from 32 to 31, 29, 38 to 41, T1 to T3.
  • the circuit shown in FIG. 3 may be modified for a reversing armature arrangement by connecting the field across 2 and 3 and the armature across 11 and 12.
  • the reversing switch is in position R.
  • the circuit is then from T3 to 1, 2, 3, 20, 21, 22, 16, to 5 inclusive, 23, 18, 19 and to T2.
  • the wash/spin selector is in position S.
  • the circuit is then from T3 to 1, 2, 3, 20, 24, 7 to 14 inclusive, 25,, 19 and T2.
  • the wash/spin selector is at S and the relay contacts are in position B.
  • the armature-field shunt circuit is then from T3 to 1, 2, 3, 20, 21, 27, 12 to 9 inclusive 26, 31 to 35 inclusive T1, to T3.
  • the interlock solenoid parallel circuit with heater element is from 31, to 30, 28, 45, 46, 47, T1 to T3.
  • the circuit shown in FIG. 4 may be modified for a reversing field arrangement by connecting the armature across 1 and 2 and the field across 10 and 11.
  • the reversing switch is in position R.
  • the circuit is then from T3 to 1 to 4 inclusive, 22, 23, 24, 18 to 6 inclusive, 25, 20, 21 and T2.
  • the wash/spin selector is in position S.
  • the circuit is then from T3 to 1 to 4 inclusive, 22, 26, 8 to 12 inclusive 42, 27, 21 and T2.
  • the wash/spin selector is in position S and the relay contacts are in position B.
  • the armature field shunt circuit is then from T3 to 1, 35, 34, 33, 28, 10 to 14 inclusive, 29, 23, 22, 4 to 1 inclusive and to T3.
  • the interlock solenoid parallel circuit with the brake load resistor is from 33 to 32, 30, 36 to 38 inclusive, T1 to T3.
  • the reversing switch is in position R.
  • the circuit is then from T3 to 1, 2, 3, 21, 22, 23, 17 to 5 inclusive, 24, 19, 20 and to T2.
  • the wash/ spin selector is in position S.
  • the circuit is then from T3 to 1, 2, 3, 21, 25, 7 to 11 inclusive 27, 26, 20 and to T2.
  • the wash/ spin selector is in position S and the relay contacts are in position B.
  • the armature-field shunt circuit is then from T3, to 1, 2, 3, 21, 22, 29, 13 to 9 inclusive 28, 33 to 35 inclusive 40, 41, T1 to T3.
  • the interlock solenoid parallel circuit with the heater element is from 33 to 32, 30, 47, 48, 49, 46, 41 to T1 and via the control to T3.
  • This control is the electronic speed control for the electric motor and has its terminal T3 joined to the neutral terminal T1 via in effect two resistors of low ohmic value (e.g. of the order of 0.05 ohm each) during the braking mode.
  • T1, T2 and T3 terminals can, therefore, be regarded as being at the same potential, for the purpose of illustration; it is to be understood however that a current is delivered between T2 and T3 in normal running.
  • a current is delivered between T2 and T3 in normal running.
  • aramture or field connections are reversed to prevent damage to semiconductors in the control.
  • FIG. 7 differs from those of FIGS. 1 to 6 in that a rectifier bridge is used in the control.
  • a rectifier bridge is used in the control.
  • the use of a rectifier bridge enables a smoother wider-range progression of control so that a wash spin selector S2 is not required.
  • the output terminals of the bridge operate in push-pull so neither is effectively at earth potential and the bridge cannot accept regenerated currents without possible damage to semi-conductors therein.
  • FIG. 7 shows a series connected direct current motor consisting of an armature A and a field winding S4.
  • An externally actuated relay S1 operates contacts to reverse the connections to the armature A (or if desired the field winding S4) under the control of a suitable timing circuit.
  • a variable direct current supply for the motor is obtained from a controlled full wave rectifier module M1 in the control C1 to regulate the speed of the motor.
  • the rectifier module M1 is powered by an alternating current mains supply having line and neutral connections (L and T1 respectively).
  • This mains supply is connected across a heater S through contacts 36, 37 and contacts 38, 39 which are operated respectively, in response to an external programme signal and in response to a Water level signal.
  • a door latch solenoid C3 In parallel with the heater across the mains supply there are a door latch solenoid C3 and a braking relay C2 (not shown).
  • This braking relay is normally energised but on a programmed machine switch off or a fault in the mains supply disconnects the motor from the rectifier module and reconnects the motor across the heater.
  • another set of contacts disconnects the door latch solenoid C3 from the now dead mains supply and reconnects it to the alternative power source provided by the regenerative braking of the motor, that is the door latch solenoid is connected in parallel with the heater.
  • the braking relay contacts are at N and the reversing switch contacts are at F.
  • the circuit is from T2, through 2 to 13 inclusive to T3.
  • the circuits is from T2 through 2 to 4, 15, 9 to 6, 16, 11, to 13 and T3.
  • the reversing switch is returned to F and the braking relay is put to B.
  • the circuit is 3 to 12, 18, 23, 24, 17 back to 3 with an ancillary door interlock solenoid circuit across 23 and 24 through 19, 21 and 22.
  • a heater may not be employed in the machinery or it may be desired to use a separate braking resistor; the circuit is the same but the connection containing contacts 36, 37 and 38, 39 is omitted.
  • the rectifier module will be completely isolated from the motor during regenerative braking and thus the rectifiers therein 6 are protected from damage.
  • the circuit as shown With the braking contacts immediately adjacent the module, no more contacts are needed on either relay than were used in the corresponding relays of FIGS. 1 to 6.
  • a similar arrangement can be devised to completely isolate the rectifier module if a tapped field motor is used but because of the flexibility of a controlled full wave rectifier a tapped field motor will not normally be required.
  • a cabinet for electrically driven machinery having a door, a lock for said door, an electrically energised device for retaining said lock in its door locking state, and means for causing an electric driving motor for said machinery to operate temporarily as a generator when it is switched off and to supply electric current to said device for retaining said lock in its door locking state whereby the door cannot be opened until the speed of said machinery has fallen to safe limit.
  • a cabinet according to claim 3 wherein the resistor is a heating element normally connected to a power supply.
  • a cabinet according to claim 4 having a semi-conductor variable speed control normally connected in series with said motor for the energization thereof.
  • a cabinet according to claim 5 having a control with two terminals supplying a variable current to the motor which is a direct current series connected motor.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Stopping Of Electric Motors (AREA)
  • Detail Structures Of Washing Machines And Dryers (AREA)
US871892A 1968-10-31 1969-10-28 Locking device Expired - Lifetime US3608337A (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GB5169668 1968-10-31
GB00363/69A GB1243376A (en) 1968-10-31 1968-10-31 Improvements in or relating to locking means for the doors of cabinets or casings housing electrically driven machinery
GB5169768 1968-10-31

Publications (1)

Publication Number Publication Date
US3608337A true US3608337A (en) 1971-09-28

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Application Number Title Priority Date Filing Date
US871892A Expired - Lifetime US3608337A (en) 1968-10-31 1969-10-28 Locking device

Country Status (5)

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US (1) US3608337A (de)
CH (1) CH499661A (de)
DE (1) DE1954608A1 (de)
FR (1) FR2022040A1 (de)
NL (1) NL6916358A (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4245488A (en) * 1980-01-04 1981-01-20 General Electric Company Use of motor power control circuit losses in a clothes washing machine
US5050271A (en) * 1989-04-19 1991-09-24 Trutzschler Gmbh & Co. Kg Rotation and standstill responsive locking device for an access door of a textile machine
WO2011045762A1 (en) * 2009-10-15 2011-04-21 Indesit Company S.P.A. Household appliance, particularly for treating textile items

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2296723A1 (fr) * 1974-12-31 1976-07-30 Thomson Brandt Machine a laver munie d'un dispositif de securite de porte
FR2459321A1 (fr) * 1979-06-20 1981-01-09 Amiens Const Elect Mec Dispositif de chauffage accelere du bain lessiviel d'une machine a laver le linge a tambour rotatif
AT390699B (de) * 1986-05-27 1990-06-11 Austria Antriebstech Einrichtung zur feststellung des stillstands eines drehstrom-asynchronmotors
GB9802983D0 (en) * 1998-02-13 1998-04-08 Rover Group Motor vehicle access hatch
DE102010027158B4 (de) * 2010-07-14 2012-06-06 Diehl Ako Stiftung & Co. Kg Wäschebehandlungsgerät

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4245488A (en) * 1980-01-04 1981-01-20 General Electric Company Use of motor power control circuit losses in a clothes washing machine
US5050271A (en) * 1989-04-19 1991-09-24 Trutzschler Gmbh & Co. Kg Rotation and standstill responsive locking device for an access door of a textile machine
WO2011045762A1 (en) * 2009-10-15 2011-04-21 Indesit Company S.P.A. Household appliance, particularly for treating textile items

Also Published As

Publication number Publication date
DE1954608A1 (de) 1970-06-18
NL6916358A (de) 1970-05-04
FR2022040A1 (de) 1970-07-24
CH499661A (de) 1970-11-30

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