U.S. patent number 3,857,076 [Application Number 05/323,780] was granted by the patent office on 1974-12-24 for upright vacuum cleaner--drive motor control.
This patent grant is currently assigned to Whirlpool Corporation. Invention is credited to Thomas Erwin Hetland.
United States Patent |
3,857,076 |
Hetland |
December 24, 1974 |
UPRIGHT VACUUM CLEANER--DRIVE MOTOR CONTROL
Abstract
A vacuum cleaner structure having self-propelling means. A
handle is associated with the vacuum cleaner and the
self-propelling means to drive the vacuum cleaner in accordance
with force applied forwardly or rearwardly to the handle. The
handle is biased to an Off position. The driving force developed by
the propelling means varies as a function of the displacement of
the handle from the Off position.
Inventors: |
Hetland; Thomas Erwin (White
Bear Lake, MN) |
Assignee: |
Whirlpool Corporation (Benton
Harbor, MI)
|
Family
ID: |
23260696 |
Appl.
No.: |
05/323,780 |
Filed: |
January 15, 1973 |
Current U.S.
Class: |
318/257; 318/295;
327/456; 327/446 |
Current CPC
Class: |
H02P
7/295 (20130101); A47L 9/325 (20130101); A47L
9/009 (20130101); A47L 5/28 (20130101); A47L
9/2852 (20130101) |
Current International
Class: |
A47L
5/28 (20060101); A47L 9/00 (20060101); A47L
9/28 (20060101); A47L 9/32 (20060101); A47L
5/22 (20060101); H02P 7/18 (20060101); H02P
7/295 (20060101); H02p 005/16 () |
Field of
Search: |
;318/256,257,291,293,295,313,345,260,271,276,305,416,436 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Schaefer; Robert K.
Assistant Examiner: Langer; Thomas
Attorney, Agent or Firm: Hofgren, Wegner, Allen, Stellman
& McCord
Claims
I claim:
1. In a vacuum cleaner having a selectively positionable operating
handle and a wheeled drive including an electric drive motor,
conductor means for connecting the vacuum cleaner to an alternating
current power supply, the wheels driven by said motor, control
means for controlling the propelling of the vacuum cleaner by said
wheeled drive comprising: a direct current motor; a bidirectional
triode thyristor in series with said motor and said conductor means
and having a control gate element; and means responsive to the
position of said operating handle relative to an "Off" position
thereof for controlling said control gate element and
correspondingly providing phase controlled conduction of direct
current through said motor during similar polarity half cycles of
the alternating current power, including a bidirectional trigger
diode having one terminal connected to said control gate element,
parallel connected inverse diodes connected to the other terminal
of said trigger diode, a capacitor connected between said other
terminal of the trigger diode and said conductor means, and
adjustable means including adjustable resistance means electrically
connected in series with said inverse diodes and said trigger
diode, and to said conductor means, said adjustable resistance
means including a first resistance portion having a terminal
connected to one of said diodes, a second resistance portion having
a terminal connected to the other of said diodes, and means
interconnecting said resistance portions opposite from said
terminals to said conduction means, the adjustable resistance means
being adjusted in response to positioning of said handle relative
to said Off position and providing preferential current flow
through a selected one of said diodes depending on the direction of
movement of said handle from said Off position.
2. In a vacuum cleaner having a selectively positionable operating
handle and a wheeled drive including an electric drive motor,
conductor means for connecting the vacuum cleaner to an alternating
current power supply, and wheels driven by said motor, control
means for controlling the propelling of the vacuum cleaner by said
wheeled drive comprising: a direct current motor; a first,
bidirectional electronic switch means in series with said motor and
said conductor means and having a control gate element; and means
responsive to the position of said operating handle relative to an
Off position thereof for controlling said control gate element and
correspondingly providing phase controlled conduction of direct
current through said motor during similar polarity half cycles of
the alternating current power to operate said drive motor
selectively in either a forward driving direction or a rearward
driving direction, including a bidirectional trigger diode
connected to said control gate element, parallel connected inverse
diodes connected in series with said trigger diode, and manually
operable adjustable means electrically connected in series with
said inverse diodes and said trigger diode, and to said conductor
means, said adjustable means being responsive to the direction and
magnitude of displacement of said handle from said Off position for
causing preferential conduction of current through a corresponding
selected one of said inverse diodes for causing said second
electronic switch means to control said first electronic switch
means to effect said selective controlled operation of said drive
motor.
3. The vacuum cleaner means of claim 2 wherein said control means
includes biasing means urging said handle to said Off position when
the handle is released.
4. The vacuum cleaner control means of claim 2 wherein said
adjustable means includes variable resistance means.
5. The vacuum cleaner control means of claim 4 wherein said
resistance means comprises a potentiometer having its resistor
connected between the inverse diodes, and its slider connected to a
fixed resistor.
6. The vacuum cleaner control means of claim 4 wherein said
resistance means comprises a potentiometer having its resistor
connected between the inverse diodes and its slider connected to
said motor through a fixed resistor.
7. The vacuum cleaner control means of claim 4 wherein said
resistance means comprises a potentiometer having its resistor
connected between the inverse diodes and its slider connected to
said motor, the resistor of said potentiometer having a gap at the
center thereof for defining an Off arrangement when the slider is
positioned at said gap.
8. The vacuum cleaner control means of claim 2 wherein said
adjustable means comprises photocell means and means for varying
the amount of light striking the photocell means as a function of
the position of said handle.
9. The vacuum cleaner control means of claim 2 wherein said
adjustable means comprises photocell means, light source means for
actuating the photocell means, and mask means interposed between
the photocell and light source means for varying the amount of
light falling on said photocell means from said source means as a
function of the position of said handle for causing said photocell
means to control operation of the motor.
10. The vacuum cleaner control means of claim 9 wherein said
adjustable means further comprises selector means for selectively
connecting the photocell means alternatively to either of said
inverse diodes comprising a double throw switch arranged to be
operated by said handle.
11. The vacuum cleaner control means of claim 2 wherein said
bidirectional trigger diode has one terminal connected to said
control gate element, said inverse diodes being connected to the
other terminal of the trigger diode, said means for controlling the
control gate element further including a capacitor connected
between said other terminal of the trigger diode and said power
supply, and said adjustable means comprises resistance means.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to vacuum cleaners and the like, and
in particular to an improved control means for use in propelling
vacuum cleaners and the like.
2. Description of the Prior Art
United States Letters Patent which would appear to be pertinent to
the present invention are as follows:
716,065 Ledwinka Automobile 1,076,652 Hoffmann Driving Mechanism
for Vehicles 1,098,849 Smart et al Switch 1,242,115 Russel Switch
for Dental Instruments 1,723,371 Pieper Combined Tool Handle and
Switch 1,813,856 Klein Direct Drive for Antifriction Roller Bearing
Free Wheels 1,953,340 Doemling Suction Cleaner 2,041,442 Stinsman
Floor Polishing Machine 2,138,239 Irgens Self-Propelled Implement
2,348,053 Bowker Electrically Operated Motor Vehicles 2,706,008
Voigt Powered Golf Bag Carrier 2,823,411 Kirby Vacuum Cleaner
2,879,858 Thomas Battery Energized, Motor- Driven Vehicle 2,937,706
Chandler Self-Propelled Carts 3,095,534 Cockrell Circuit for
Controlling Energization of a Direct Current Load 3,195,029
Gilbreath Series Motor Control 3,222,582 Heyman et al Variable
Speed Motor System Utilizing Controlled Rectifiers 3,225,853 Norton
et al Control Handle for Golf Cart 3,354,496 Jonsson Suction
Cleaner Nozzle of the Agitator Type 3,385,077 Marsteller Air
Conditioner 3,475,676 Hutson Photosensitive Power Control System
3,489,874 Baumann Control Switch for an Electric Dry Razor
Ledwinka U.S. Pat. No. 716,065 shows an automobile construction
utilizing an early propelling means.
Hoffman U.S. Pat. No. 1,076,652 shows another form of early drive
mechanism for propelling a vehicle.
Smart et al. U.S. Pat. No. 1,098,849 show a switch adapted to be
operated by the longitudinal movement of an actuating member.
Russell U.S. Pat. No. 1,242,115 shows a longitudinal movable switch
for use in a dental instrument. Pieper U.S. Pat. No. 1,723,371
shows a similar switch.
Klein U.S. Pat. No. 1,813,856 shows a drive having an electric
motor for each of a plurality of wheels.
Doemling U.S. Pat. No. 1,953,340 shows a vacuum cleaner wherein an
agitator is driven from an actuating motor separate from the fan
motor.
Stinsman U.S. Pat. No. 2,041,442 shows a floor polishing machine
having a fan for ventilating the motor elements.
Irgens U.S. Pat. No. 2,138,239 shows a self-propelled powered
lawnmower having a handle grip for controlling forward and rearward
movement of the lawnmower.
Bowker U.S. Pat. No. 2,348,053 shows a battery operated motor
vehicle having a dynamotor within each wheel.
Voigt U.S. Pat. No. 2,706,008 shows a powered golf bag carrier
having a worm gear arrangement providing increased power under
heavy loading conditions and braking means to secure the carrier in
a stationary position.
Kirby U.S. Pat. No. 2,823,411 shows a vacuum cleaner with the fan
motor also driving a brush in the nozzle.
Thomas U.S. Pat. No. 2,879,858 shows a battery driven vehicle
wherein the current supplied to the drive motor is varied in
accordance with the tension applied to the handle thereof.
Chandler U.S. Pat. No. 2,937,706 shows a self-propelled cart having
a handle controlling the electric drive motor thereof with the
amount of pull on the handle varying the force developed by the
motor.
Cockrell U.S. Pat. No. 3,095,534 shows a circuit for controlling
energization of a direct current load utilizing a controlled
rectifier in controlling the current to the motor armature.
Gilbreath U.S. Pat. No. 3,195,029 shows a series motor control
using a controlled rectifier in similarly controlling the current
to the motor armature. Heyman et al. U.S. Pat. No. 3,222,582 shows
a motor system utilizing controlled rectifiers.
Norton et al. U.S. Pat. No. 3,225,853 show a control handle for a
golf cart providing adjustable power as a function of the magnitude
of the applied force.
Jonsson U.S. Pat. No. 3,354,496 shows a vacuum cleaner nozzle
having an agitator driven by an electric motor.
Marsteller U.S. Pat. No. 3,385,077 shows an air conditioner wherein
modulation of the air flow is controlled by an optical system
utilizing a photocell. Hutson U.S. Pat. No. 3,475,676 shows a
photosensitive power control system utilizing similar optical
means.
Baumann U.S. Pat. No. 3,489,874 shows a control switch for an
electric razor having an operating knob which is selectively
slidable, pivotable, or rockable in the casing.
Thus, the prior art shows the concept of propelling means such as
automobiles, lawnmowers, golf bag carriers, and golf carts by
self-contained motor driven power means. The art further shows the
use of push-pull, longitudinally movable controls such as in
electric switches, dental instruments, lawnmowers, and golf
carts.
The prior art further shows the use of vacuum cleaners having motor
driven suction fans and motor driven agitators. Still further, it
is known to use direct current motors for reverse driving of
devices and to use controlled rectifier means for controlling the
current flow to such a motor for varying the speed and torque
thereof.
SUMMARY OF THE INVENTION
The present invention comprehends a vacuum cleaner construction
having new and improved control means for effecting controlled
self-propelling thereof. The movement of the vacuum cleaner is
effected by application of force to the handle thereof for
controlling the drive motor through the new and improved control
means.
More specifically, the control effects rectification of an
alternating current power supply to permit use of a direct current
motor as the propelling drive means.
The propelling means includes wheels carried on the oppositely
projecting shaft ends of the drive motor. The wheels may define
means for deflecting cooling air against the motor. The wheeled
drive may be mounted to the carriage of the vacuum cleaner or to
the nozzle in different embodiments of the invention. The cooling
air may be drawn through the motor by the vacuum cleaner suction
fan or may be delivered to the motor under pressure from the
suction fan in different embodiments of the invention. The cooling
air may comprise air from which dirt has been removed by the vacuum
cleaner. Alternatively, the cooling air may comprise atmospheric
air drawn by the suction fan concurrently with the drawing of the
dirt laden air to the dirt separating means. The cooling air may be
passed through the interior of the motor housing through suitable
openings therein and may also be directed against the exterior of
the housing by deflecting means such as the drive wheels as
discussed above.
The drive wheels may comprise cup-shaped elements partially
surrounding the motor housing while leaving a passage therebetween
intermediate the ends of the motor housing for passing cooling air
therethrough.
The means for controlling the operation of the propelling motor may
include an electronic switch phase controlled to vary the current
to the motor as a function of the position of the handle means. The
control may function to provide power during each half cycle of the
alternating current power supply. Alternatively, the control may
function to provide current only during similar polarity half
cycles of the alternating current power supply to selectively
reversely operate the motor as a function of the selected
polarity.
The phase controlled electronic switch may comprise a controlled
rectifier. In one form, the rectifier comprises a bidirectional
triode thyristor. In another embodiment, the rectifier comprises a
silicon controlled rectifier. In one embodiment, the means for
controlling the control gate of the controlled rectifier comprises
a bidirectional trigger diode. In another embodiment, the means for
controlling the control gate comprises a silicon unilateral
switch.
Phase control of the controlled rectifier may be provided by
varying a resistance in the control circuit thereof. In one
embodiment, the variable resistance comprises a potentiometer. The
potentiometer may have a gap in the mid-portion of the resistor
thereof to provide an Off condition. In another embodiment, the
variable resistor comprises a photocell and means for varying the
amount of light striking the photocell from a light source for
providing a low cost, long life adjustable resistance means. The
means for varying the transmitted light may comprise a suitable
mask positioned by the handle of the vacuum cleaner.
In another embodiment of control wherein the motor is operated only
on similar polarity half cycles of the alternating current power
supply, the variable resistance is connected to the means for
triggering the controlled rectifier through a parallel inverse
diode circuit. Selection of the polarity of the motor operating
current may be obtained by connecting a potentiometer resistor
across the parallel circuit with the slider of the potentiometer
connected to the motor. Alternatively, selection of the polarity
may be effected by a selector switch having the moving contact
selectively engageable with fixed contacts connected one each to
the different inversely connected diodes.
More specifically, the present invention comprehends the provision
in a vacuum cleaner having an operating handle and a wheeled drive
including an electric drive motor and wheels driven by said motor,
of control means for controlling the propelling of the vacuum
cleaner by the wheeled drive comprising a direct current motor, a
full wave rectifier for supplying direct current to said motor from
an alternating current power supply, an electronic switch in series
with the motor having a control gate element, and means responsive
to the position of the operating handle relative to an Off position
thereof for controlling the control gate element and
correspondingly providing phase controlled conduction of direct
current through the motor during each half cycle of the alternating
current power.
Further more specifically, the electronic switch thereof may
comprise a bidirectional triode thyristor and the means responsive
to the position of the operating handle for controlling the
thyristor may include a bidirectional trigger diode having one
terminal connected to the control gate element, parallel, inverse
diodes connected to the other terminal of the trigger diode, a
capacitor connected between the other terminal of the trigger diode
and the power supply, and resistance means adjustably connected to
the inverse diodes.
Further more specifically, alternatively, the invention comprehends
the provision in a vacuum cleaner having an operating handle and a
wheeled drive including an electric drive motor and wheels driven
by the motor, of control means for controlling the propelling of
the vacuum cleaner by the wheeled drive comprising a direct current
motor, adjustable phase controlled means for providing current to
the motor only during similar polarity half cycles of the
alternating current power, and means for selecting the half cycle
polarity during which the current is provided for selective
reversible operation of the motor.
BRIEF DESCRIPTION OF THE DRAWING
Other features and advantages of the invention will be apparent
from the following description taken in connection with the
accompanying drawing wherein:
FIG. 1 is a perspective view of a vacuum cleaner embodying the
invention;
FIG. 2 is a fragmentary rear elevation thereof with portions of the
rear cover of the bag enclosure removed to illustrate details;
FIG. 3 is a fragmentary bottom plan view thereof;
FIG. 4 is a fragmentary enlarged vertical section illustrating the
handle switch control means;
FIG. 5 is a fragmentary vertical section illustrating the
propelling means mounted to the carriage of the vacuum cleaner;
FIG. 6 is a diametric section taken substantially along the line
6--6 of FIG. 5;
FIG. 7 is a schematic wiring diagram of the electric drive
control;
FIG. 8 is a fragmentary plan view with portions broken away
illustrating one embodiment of the invention wherein cooling air is
delivered from the suction fan to the drive motor;
FIG. 9 is a fragmentary side elevation thereof;
FIG. 10 is a fragmentary side elevation thereof with the nozzle in
a raised position;
FIG. 11 is a plan view illustrating another embodiment of the
invention wherein cooling air is sucked through the drive motor to
pass with dirt laden air to the dirt separating means;
FIG. 12 is a fragmentary side elevation thereof;
FIG. 13 is a fragmentary side elevation thereof with the nozzle in
a raised position;
FIG. 14 is a plan view illustrating another embodiment of the
invention wherein cooling air is drawn through the drive motor to
the suction inlet of the fan;
FIG. 15 is a fragmentary side elevation thereof;
FIG. 16 is a fragmentary side elevation thereof with the nozzle in
a raised position;
FIG. 17 is a fragmentary side elevation of the vacuum cleaner
construction of FIG. 5;
FIG. 18 is a fragmentary side elevation thereof with the nozzle in
a raised position;
FIG. 19 is a schematic wiring diagram of a modified form of
electrical control of the drive means;
FIG. 20 is a schematic wiring diagram illustrating a still further
modified control;
FIG. 21 is an elevation of a mask for use in the control of FIGS.
20 and 24;
FIG. 22 is a schematic wiring diagram of yet another modified form
of control;
FIG. 23 is a fragmentary schematic wiring diagram illustrating a
modification of the control of FIG. 22; and
FIG. 24 is a schematic wiring diagram of yet another drive control
embodying the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the exemplary embodiments of the invention as disclosed in the
drawing, a vacuum cleaner generally designated 10 is shown to
comprise an upright vacuum cleaner having a nozzle 11 and an
upstanding bag enclosure 12 provided with a front closure 51. The
nozzle is mounted to a carriage 13 herein provided with rear wheels
14. A brush and beater bar 15 is mounted at the front of the nozzle
to be driven from the suction fan motor 16 by suitable means (not
shown). Herein the vacuum cleaner is driven by a propelling means
generally designated 17 comprising a drive motor 18 and a pair of
drive wheels 19 and 20 secured to the oppositely projecting shaft
ends 21 and 22 of the drive motor. As shown in FIGS. 5 and 6, the
housing 23 of the drive motor may be secured to the carriage 13 by
a suitable bracket 24 and screws 25.
Wheels 19 and 20 define cup-shaped elements facing toward each
other coaxially of the motor as illustrated in FIG. 6. Thus, wheel
19 defines an end wall 26 and a cylindrical side wall 27, and wheel
20 defines an end wall 28 and a cylindrical side wall 29. The
distal end 30 of wheel side wall 27 is spaced longitudinally from
the distal end 31 of side wall 29 to define a space 32 therebetween
for passing cooling air.
As illustrated in FIGS. 5, 6, 8, 17 and 18, cooling air may be
delivered from the suction fan 45 through a duct 33 to the interior
of motor housing 23 through an inlet opening 34 in the housing.
After passing through the housing, the cooling air may exhaust
through the opposite ends 35 and 36 of the housing. As shown in
FIGS. 6 and 8, the cup-shaped wheels are spaced axially and
circumferentially from the housing to define flow paths 37 whereby
the air deflected by the wheels is delivered to the space 32 to
exhaust to the atmosphere. As shown in FIG. 8, the dirt laden air
is conducted to bag 39 by means of a duct 40 extending from the
nozzle 11 into the enclosure 12 wherein the bag is received. A duct
41 connects the enclosure 12 to the suction inlet 42 of the fan 45.
The shroud 43 extending about the fan motor 16 is provided with a
discharge opening 44 for discharging air from the fan 45 to
atmosphere. As shown in FIG. 8, the duct 33 opens through the
shroud 43 for receiving a portion of the air delivered from fan 45
for delivery to the drive motor.
As shown in FIGS. 17 and 18, the nozzle 11 may be pivoted on the
carriage 13 by means of a projection 46 on housing 12 engaging a
lever 47 pivotally mounted on a bracket 48 carried by the carriage
13. Thus, the wheel drive 17 is maintained in engagement with the
subjacent floor F while the nozzle may be pivoted to space the
brush and beater bar above the floor level by suitable pivoting of
the enclosure 12 on the carriage. Duct 33 maintains the connection
between the suction fan and motor 18 in the different relationships
of the nozzle and carriage, as illustrated in FIGS. 17 and 18.
Vacuum cleaner 10 is propelled on the subjacent floor by suitable
energization of drive motor 18 as a result of pressure applied to a
handle 49 upstanding from the bag housing 12, as illustrated in
FIG. 1. As shown in FIG. 2, bag enclosure 12 includes a rear
portion 50. Removal of rear closure 52 of housing 12 provides
access to the space 52a within the rear portion 50. Handle 49
extends through the top wall 53 of the housing portion 50 and is
provided with a slide tube 54 internally carrying a housing 55
defining a cam 56 selectively engageable with the actuator 57 of a
first switch 58 and the actuator 59 of a second switch 60. The
switches are carried on the rear housing portion 50. A centering
device generally designated 61 is mounted in housing 55 for
centering the cam 56 between the actuators 57 and 59, as shown in
FIG. 4.
More specifically, the centering device includes a rod 62 fixedly
secured to the housing portion 50 by a pin 63. Rod 62 is provided
with a pin 64 intermediate the ends 65 and 66 of housing 55. A
first coil spring 67 extends coaxially about rod 62 to a washer 68
slidably mounted on the rod adjacent pin 64. A second coil spring
69 extends from housing end 65 to a washer 70 slidably mounted on
rod 62 oppositely adjacent pin 64. Slide tube 54 further is
provided with an actuator 71, as shown in FIG. 2, for controlling
the setting of a potentiometer 72 carried on the housing portion
50. As further shown in FIG. 2, a control 73 is mounted on the
housing portion 50 adjacent upper wall 53 and a cord reel 74 is
mounted to the housing portion 50 at the lower opposite end with a
power supply cord 75 extending from reel 74 outwardly through the
housing for connecting the vacuum cleaner to a power source such as
a conventional wall receptacle (not shown).
Operation of the vacuum cleaner may best be understood by reference
to the schematic electrical wiring diagram of FIG. 7. As shown,
drive motor 18 illustratively comprises a permanent magnet direct
current motor having an armature 76 connected between the moving
contacts 60a of switch 60 and contacts 58a of switch 58. Direct
current power is delivered to the motor 18 from alternating current
power supply leads L1 and L2 connected to a full wave bridge
rectifier 77 through a single pole, single throw interlock switch
78. The positive output terminal 77a of the full wave bridge
rectifier is connected to fixed contacts 60b and 58b of switches 60
and 58, respectively. A resistor 79 and a resistor 80 are connected
in series between terminal 77a and the negative terminal 77b of
rectifier 77. Diode 81 is connected between terminal 77a and second
fixed contact 60c of switch 60 and second fixed contact 58c of
switch 58 and through a silicon controlled rectifier 82 to negative
terminal 77b. Diode 81 is further connected through a second
inversely related diode 83 to the potentiometer 72, having its
slider 72a connected to a fixed resistor 84 and a drive motor speed
selector switch 85. Switch 85, in turn, is connected through a
fixed resistor 86 and a capacitor 87 to power terminal 77b. A
silicon unilateral switch 88 has its gate 88a connected to terminal
89 between resistors 79 and 80. Switch 88 is connected from a
terminal 90 between resistor 86 and capacitor 87 to the gate 82a of
the silicon controlled rectifier 82. A resistor 91 is connected
from rectifier gate 82a to power terminal 77b and a series
connection of a resistor 92 and capacitor 93 is connected across
the rectifier gate 82a. A jumper 72b is connected to the opposite
ends of the resistor 72c of potentiometer 72.
As discussed above, longitudinal movement of handle 49 by the
application of force thereto by the user's hand, as shown in FIG.
1, causes a corresponding movement of cam 56, as shown in FIG. 4,
to actuate either forward switch 60 or reverse switch 58 as a
function of the direction of force application to the handle.
Further, the amount of longitudinal handle movement effected
controls the positioning of the slider 72a of potentiometer 72 to
control the silicon unilateral switch 88 and thereby control the
amount of current passed by the controlled rectifier 82 thereby to
control the speed and torque of the motor 18. As shown in FIG. 7,
when forward switch 60 is closed, i.e., by a downward movement of
cam 56 (FIG. 4), moving contact 60a closes with fixed contact 60b
to provide power from positive power supply terminal 77a through
motor armature 76, switch 58 and through the silicon controlled
rectifier to negative terminal 77b. Phase control of silicon
controlled rectifier 82 is effected by the setting of slider 72a
relative to resistor 72c of potentiometer 72 so as to vary the
amount the current passed by rectifier 82 depending on the amount
of displacement of slider 72a from the center position 72d of
resistor 72c.
Reversely, similarly, where the handle is moved rearwardly so as to
move cam 56 upwardly to close switch 58, positive power supply
terminal 77a is connected through moving contact 58a of switch 58
to motor armature 76 and through switch 60 and silicon controlled
rectifier to the negative power terminal 77b causing a reverse
operation of the motor 18 under the speed control of potentiometer
72.
Electrical components of one control found to provide excellent
functioning as described above, are as follows:
18 Motor American Lincoln PM DC 72 Potentiometer 0 to 1 Megohm 79
Resistor 220 Kilohms 80 Resistor 2.2 Kilohms 81 Diode 1N1694 82
Silicon Controlled Rectifier GE C22B 83 Diode 1N1694 84 Resistor
330 Kilohms 86 Resistor 1 Kilohm 87 Capacitor 0.8 mfd. 88 Silicon
Unilateral Switch GE 2N4987 91 Resistor 100 Ohms 92 Resistor 33
Ohms 93 Capacitor 0.01 mfd.
Modified controls suitable for use in controlling the operation of
a motor corresponding to motor 18 are illustrated in FIGS. 19-24.
As shown in FIG. 19, a control generally designated 173 is shown to
include a full wave rectifier 177 connected to the alternating
current power supply leads L1 and L2. A selector switch 194 is
connected to the output terminals 177a and 177b of the power supply
for selectively connecting power supply terminal 177a to a motor
terminal 195 or a terminal 196 and power supply terminal 177b
concurrently to terminal 196 or terminal 195 as a function of the
position of the vacuum cleaner handle. The means for controlling
current through the motor 181 comprises a controlled rectifier
illustratively comprising a bidirectional triode thyristor, or
triac, 197 having its gate 197a controlled by a bidirectional
trigger diode, or diac, 198 connected in series with a fixed
resistor 199 and a potentiometer 172 to a terminal 200 connected
between motor 181 and triac 197. Triac 197 is connected between
motor 181 and terminal 196 and a capacitor 201 is connected from a
terminal 202 between diac 198 and resistor 199 and terminal 196 and
the resistor 172c has its opposite ends connected by a jumper
172b.
Thus, current flow to motor 181 is controlled by the triac 197
under the phase control of diac 198 which, in turn, is controlled
by the setting of potentiometer slider 172a and switch 194 by the
vacuum cleaner handle to provide selectively reversible operation
of the vacuum cleaner wheeled drive motor at different speeds and
torques as desired.
As shown in FIG. 20, the portion of the control 173 connected to
terminals 195 and 196 may be modified to utilize a photocell 203 in
lieu of potentiometer 172 as a variable resistance for controlling
the diac 198. A neon lamp 204 may be connected between terminals
195 and 196 for directing light to the photocell 203. A mask 205
carried for movement with the vacuum cleaner handle 49 is
interposed between lamp 204 and photocell 203 to control the
resistance of the photocell. As shown in FIG. 21, the mask 205
includes an opaque portion 205a defined by downwardly opening cusps
205b and upwardly opening cusps 205c for varying the amount of
light received by the photocell as a function of the movement of
the mask from a centered position under the control of the vacuum
cleaner handle. The control of FIG. 20 thus provides an improved
long life control as frictional wear of control elements is
avoided.
Referring to FIGS. 22-24, further modified control means for
controlling a wheeled drive motor 183 of the vacuum cleaner are
shown to provide such control under half wave voltage conditions.
More specifically, as shown in FIG. 22, motor 183 may be connected
through a triac 1973 across the alternating current power supply
leads L1 and L2. The triac is phase controlled by a diac 1983
connected to its gate 197a. A capacitor 2013 is connected from
power supply lead L2 to terminal 202. A fixed resistor 1993 is
connected from terminal 200 to the slider 172a of potentiometer
1723 having its resistor 172c connected between parallel inverse
diodes 206 and 207 which, in turn, are connected to terminal 202.
Resistor 172c preferably has a relatively high value, such as 4 or
5 megohms, and thus prevents triggering of the triac 1973 when in
the center position, as shown in FIG. 22. However, when the vacuum
cleaner handle is moved in either direction to correspondingly move
the slider 172a, the triac is triggered during similar half cycles
of the alternating current power supply. Thus, illustratively, when
the slider 172a is moved upwardly, as seen in FIG. 22, the triac is
triggered on positive half cycles and when the slider is moved
downwardly, the triac is triggered on negative half cycles.
Further, as the total resistance of the circuit through the diode
varies as the amount of movement of the slider 172a, motor 183 is
controlled not only as to direction of movement, but also as to
speed and torque by the phase control of triac 1973 by diac
1983.
As shown in FIG. 23, the potentiometer may be provided with a
modified resistor 172d having a gap 172e at the center portion so
that when the slider 172a is in the center position, the control
will be in an Off condition as no current can flow to the diac 1983
from terminal 200.
Referring now to FIG. 24, a further modified control is shown to
comprise a control similar to that illustrated in FIG. 22 but
wherein the variable resistance is provided by photocell 2035 in
lieu of the potentiometer 172 and the switching function is
provided by a selector switch 208 having its moving contact 208a
connected in series with the photocell 2035, one fixed contact 208b
connected to diode 2075, and a second fixed contact 208c connected
to diode 2065. The resistance of photocell 2035 is controlled by
lamp 2045 and mask 205 as described above relative to the control
of FIG. 20. Switch 208 is operated by handle 49 concurrently with
the moving of mask 205 to provide the desired reverse operation of
vacuum cleaner drive motor 185 concurrently with the speed and
torque control thereof by the control of the variable resistance of
photocell 2035. The control of FIG. 24 is similar to the control of
FIG. 22 in that the operation of the motor 185 is by similar
polarity half cycles of the alternating current power supply by
means of the inverse parallel diodes 2065 and 2075.
Illustrative circuit components for the elements of the controls of
FIGS. 19-24 are as follows:
172 potentiometer 0-1 Megohm 177 Full wave rectifier 200 Volt PRV,
4 amp. 181 Motor American-Lincoln PM DC 194 Selector switch DPDT
197 Triac GE, SC 40B 198 Diac GE, ST-2 199 Resistor 30 Kilohms 201
Capacitor 0.1 mfd 182 Motor American-Lincoln PM DC 1972 Triac GE,
SC 40B 1982 Diac GE, ST-2 1992 Resistor 30 Kilohms 2012 Capacitor
0.1 mfd 203 Photocell Vactec VT-101H 204 Lamp Signalite Neon 1723
Potentiometer 0-1 Megohm 183 Motor American-Lincoln PM DC 1973
Triac GE, SC 40B 1983 Diac GE, ST-2 1993 Resistor 30 Kilohms 2013
Capacitor 0-1 mfd 206 Diode 1N 1694 207 Diode 1N 1694 1724
Potentiometer 0-1 Megohm 2064 Diode 1N 1694 2074 Diode 1N 1694 185
Motor American-Lincoln PM DC 1975 Triac GE, SC 40B 2035 Photocell
Vactec VT-101 H 2065 Diode 1N 1694 2075 Diode 1N 1694 2045 Lamp
Signalite Neon
The modified controls of FIGS. 19-24 function in the vacuum cleaner
structure similarly to the control 73 except as otherwise noted
above.
Referring now to FIGS. 11-16, the vacuum cleaner construction may
include modified means for effecting the delivery of cooling air to
the drive motor 18 by means of the suction fan 45. Thus, as shown
in FIGS. 11-13, a duct 209 may be connected between the motor
housing opening 34 and the suction duct 40 leading from the nozzle
11 to the dirt collecting chamber 38. Thus, the suction pressure
effected by fan 45 serving to draw dirt laden air into the vacuum
cleaner concurrently serves to draw air through the motor housing
23 to cool the drive motor by sucking the air therethrough to the
dirt separating chamber.
Referring now to FIGS. 14-16, a further modified form of vacuum
cleaner construction embodying the invention is shown to include a
duct 210 connecting the motor housing opening 340 directly to the
suction inlet 420 of the fan 450 defined by the shroud 430. Thus,
the cooling air sucked through the drive motor 180 is delivered
directly to fan 450 rather than through the dirt separating chamber
as in the embodiment of FIGS. 11-13. In all other respects, the
vacuum cleaner constructions of FIGS. 11-16 are similar to the
vacuum cleaner construction illustrated in FIGS. 8-10 and similar
elements thereof are identified by related reference numerals.
Thus, the vacuum cleaner constructions of the present invention
provide an improved facilitated propelling of the vacuum cleaner
over the surface to be cleaned. The drive motor of the propelling
means and the suction fan of the vacuum cleaner are cooperatively
associated for improved efficiency and low cost of the unit.
Improved trouble-free, long life control means are provided for
effecting desired reversible driving of the propelling means. The
vacuum cleaner constructions of the present invention are extremely
simple and economical of manufacture while yet providing the highly
desirable features discussed above.
The foregoing disclosure of specific embodiments is illustrative of
the broad inventive concepts comprehended by the invention.
* * * * *