PROVIDING A PROGRAMMER/TIMER WITH DUAL RATE DRIVE:
BACKGROUND OF THE INVENTION:
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The
present invention relates to electromechanical programmer/timers
utilized for sequentially activating at least one and usually a
plurality of electrical switches for a selective program interval.
Programmer/timers of this sort are commonly employed for appliances such
as clothes washing machines, dishwashers, microwave ovens and other
appliances wherein it is desired for the machine user to select a
desired program interval for the appliance operation; and, upon such
selection a timing motor provides advancement of a cam track for
sequentially actuating the machine control function switches during
time-out of the selected interval.
Typically, electromechanical
appliance programmer/timers utilize a subfractional horsepower
synchronous timer motor driving either a continuous drive to the cam
through a speed reducer, or employ an indexing mechanism such as a
ratchet wheel engaged by a periodically advanced and retracted pawl.
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Heretofore,
differing rates of advance in appliance programmer/timers have been
provided by utilizing ratchet teeth of varying depth disposed about the
advance ratchet with blocking means, usually comprising a masking
ratchet wheel, to permit the pawl to engage the notches of greatest
depth only upon selected multiples of the advanced pawl strokes, thus
providing alternate rates of intermittent advancement of the cam
ratchet. However, the fastest rate of advancement in such arrangement S
is determined by the number of teeth having the greatest minor diameter
on the ratchet wheel with the teeth of lesser major diameter providing a
substantially slower rate of advancement. Where continuous drive for
the cam is employed via means of a motor speed reducer, it has
heretofore been the practice to shift or change gearing in order to
provide alternate rate of advance.
However, in certain appliance
applications, it is desired to provide a relatively slow rate of
advancement utilizing the well known ratchet and pawl cam indexing;
technique however, it is also desired to provide a substantially more
rapid rate of advancement of the cam for certain selected portions of
the program time out interval. Therefor, utilizing only a ratchet and
pawl advance technique for the cam track limits the resolution of the
cam track by virtue of the pitch of the teeth required to provide the
desired maxmimum rate of advance. If the pitch of the teeth for the
ratchet is chosen for the desired maximum rate of advance, within the
allowable diameter for the ratchet, problems have been encountered in
providing the desired resolution of the cam functions within a single
revolution of the rotary cam track.
Therefore, it has long been
desired to provide an electromechanical programmer/timer for appliance
having a ratchet and pawl advance mechanism providing a relatively fast
rate of advance and yet also provide for a substantially slower rate of
advance with a continuous drive means for a portion of the selected
program interval.
SUMMARY OF THE INVENTION
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The present invention
provides an electromechanical programmer/timer for appliances having a
relatively fast rate of advance of the switch cam track provided by an
oscillating advance pawl and ratchet wheel and a substantially slower
rate of advance provided by a continuous speed reducer drive. The
ratchet is connected to drive the cam track by a first frictional clutch
means and the continuous drive is connected for driving the ratchet by a
second frictional clutch means which is permitted to slip when the pawl
is engaged for advancing the ratchet. The cam track has a portion
thereof configured to lift the advanced pawl for the ratchet, thereby
disabling the pawl and ratchet advance, whereupon the second frictional
clutch ceases to slip and the continuous drive provides for the slower
rate of advance.
User selection of the desired program interval
for the cam track is accomplished by user rotation of the cam track
which is permitted by slippage of the first and second clutch means to
enable the desired positioning of the cam track for commencement of the
timed interval for the program.
In the preferred form, the first
clutch means comprises a frictional engagement between the interior of
the hub on the ratchet wheel and a shaft connected to the cam track. A
second clutch means comprises a collet provided on the speed reducer
aftward gear with the collet frictionally engaging the exterior of the
ratchet wheel head.
The present invention thus provides a novel
and simplified instruction for a programmer/timer for appliances wherein
a single drive motor is operative to providing a fast rate of
advancement through a pawl advancing a ratchet wheel and a slower rate
through continuous drive to the ratchet wheel which slips during pawl
advancement of the ratchet.
Upon lifting of the ratchet, the
slipping clutch ceases to slip and provides a slower rate of continuous
drive to the cam track.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a
pictorial representation of the cam track ratchet advance pawl and gear
train for the programmer/timer of the present invention with the advance
pawl engaging the ratchet; Figure 2 is a view similar to Figure 1
showing the advanced pawl lifted from the ratchet by a blocking track on
the cam; and, Figure 3 is a section view taken along broken section
line 3-3 of Figure 1.
DETAILED DESCRIPTION
Referring to Figure 1,
the dual rate drive mechanism before a programmer/timer is illustrated
generally by reference numeral 10 and comprises a drum 12 mounted for
rotation about shaft 14 and having a cam track 16 provided about the
periphery thereof. A cam follower means 18 is pivotally exposed on the
base or housing means (not shown) and the follower is engaged in track
16 and is operative to effect actuation and deactuation of the
electrical switch mechanism indicated generally at 20. In the
illustration of Figure 1, the cam drum 12 is shown r
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otated to a position
such that the cam follower 18 rests against the depressed or base
circle portion 17 of cam track 16 and in this position effects
deactuation of opening of the switch 20.
The portion of cam track
16 on drum 12 disposed generally diameterally opposite the depressed
portion 17 is also depressed for a desired arcuate segment of the cam
track periphery as indicated by the reference numeral 22. A toothed
ratchet wheel having teeth 24 of substantially constant pitch and root
diameter greater than tracks 22 are formed about the periphery thereof;
and, the ratchet 25 is disposed concentrically with respect to shaft 14
and in axially spaced relationship with cam drum 12.
An advance
pawl 26 is provided and has a chisel point 28 disposed to engage the
ratchet teeth 24 as illustrated in Figure 1. Pawl 26 is connected to
orbiting concentric crank pin 30 and has the end thereof opposite to the
point 28 disposed over pin 30 and biased thereon by integrally formed
spring fingers 34, 32. It will be understood that the crank pin 30 is
rotated by a speed reducer and motor drive mechanism (not shown).
Referring
to Figure 1 and 3, the cam drum 12 is illustrated in the preferred
practice as being integrally formed on shaft 14 and is rotated therewith
by user rotation of the shaft 14 for positioning the cam track 16 at a
desired rotational position with respect to cam follower 18. Ratchet
wheel 25 is shown in Figure 3 as having an axially extending hub 36
which has the inner periphery thereof received over shaft 14 so as to
position the ratchet teeth 24 in alignment for engagement with the pawl
chisel point 28. The ratchet hub engages the shaft 14 in a frictional
engagement and comprises a first frictional clutching means indicated
generally by the numeral 37 for operatively connecting the ratchet wheel
25 for rotationally driving cam drum 12. The ratchet hub 36 has a
reduced diameter extension portion 38 extending from the hub in a
direction opposite that of the cam drum 12.
A speed reducing gear
40 has a central hub 42 provided thereon and received over shaft 14
adjacent the reduced diameter portion 38 of the ratchet hub. Gear 40 has
peripheral teeth 44 continuously engaged by a motor drive pinion gear
46 which is driven from shaft 48 by a motor comprised (not shown). It
will be understood, however, that a common motor drive may be employed
with appropriate speed reduction for the eccentric shaft 30 and for the
pinion gear 46.
The hub 42 of gear 40 has provided on the interior
thereof a plurality of collet jaws 50 which frictionally engage the
exterior of the smaller hub diameter 38 in frictional engagement and
comprise a second clutching means indicated generally by reference
numer
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al 51 in Figure 3 for providing a continuous drive from shaft 48 to
ratchet wheel 25 via gear 44 and through the first clutching means 31
to the cam drum 12.
Referring to Figure 2, the drive of Figure 1
is shown with the cam drum 12 rotated to a position where a second cam
track 52 has raised the chisel point 28 an amount sufficient to
disengage the pawl from the ratchet teeth 24. This listed position is
shown in greater detail in Figure 3.
In operation, when the cam
drum is positioned such that track 22 permits the ratchet teeth 24 to be
engaged by the pawl chisel point 28 the cam drum 12 is driven by the
first frictional clutch 37; and, the second frictional clutch 51 permits
shaft 14 to be overdriven by slippage therein.
In operation,
during the initial portion of the selected program the ratchet wheel 25
is advanced by clutch 51 engaging hub 36 with the pawl chisel point 28
lifted from the ratchet teeth 24 by cam track 52. Upon reaching the end
track 52, point 28 engages ratchet teeth 24, driving of the ratchet
wheel 25. Thereafter, the clutch means 51 begins slipping the shaft 14
is driven by clutch 37 at the speed of rotation of the gear 25. The drum
12 continues rotating until the cam track 16 reaches the recessed cam
track portion 17 whereupon cam follower drops and deactuates or opens
switch 20 to cut line power to the motor drive (not shown) for shaft 48.
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In
the presently preferred practice of the invent
ion, the pawl and ratchet
drive is operable to provide a faster rotation to cam drive 12 than the
continuously rotating pinion gear 46 driving through gear 40 and clutch
51. In one application of the invention, it has been found desirable to
rotate the eccentric shaft 30 at a rate of 4 revolutions per minute (4
RPM) thereby giving the pawl 26 a period of oscillation of 15 seconds.
Concomitantly, the driving pinion 46 is rotated at a rate of
one-fifteenth revolution per minute (1/15 RPM); and, the ration of the
number of teeth on pinion 46 to the number of gear teeth 44 is 1:4
giving the gear 40 a rate of rotation of one-sixtieth revolution per
minute (1/60 RPM).
In the present practice of the invention, in
ore application, it has been found satisfactory to have clutch 51
provided with a slippage of break-away torque of forty (40) in-ounces;
and, the clutch 37 has a break-away torque of 20 in-ounces.
When
the motor drive (not shown) for driving eccentric shaft 30 and pinion 46
is inoperative e.g. switch 20 is open, shaft 14 may be rotated by the
appliance user in either direction. If the pawl 26 is in the position
shown in Figure 2, clutch 37 will slip to permit positioning of the cam
in either direction. If the pawl is in the position shown in Figure 1,
with the chisel point engaging the ratchet teeth, clutch 37 will slip
upon user rotation of shaft 14.
The present invention provides
unique and novel dual rate drive for an electromechanical
programmer/timer for actuating appliance function switches in a sequence
during a selected program interval. The programmer/timer of the present
inve
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ntion provides a pawl and ratchet drive to a rotatable switch cam
drum in which the ratchet wheel is frictionally clutched to the cam drum
shaft; and, the ratchet wheel hub is also separately frictionally
clutched to a continuously rotating motor drive gear. Upon engagement of
the pawl with the ratchet, the friction clutch to the continuously
driven gear slips and permits the shaft to be overdriven.
Upon the
cam drum rotating to a desired position, a cam track lifts the pawl
from engagement with the advance ratchet and the shaft is not overdriven
and slippage of the gear clutch ceases and the cam drum shaft is driven
as a slower rate by the continuously rotated drive gear. Upon time-down
to the lower cam position, the pawl engages the ratchet and the drum
overdrives the continuously driven gear. The user positioning of the cam
drum is accomplished by permitting clutch 37 to slip upon user rotation
of the cam drum shaft in either direction.
The present invention
has been hereinabove described and illustrated in the drawings in the
presently preferred practice. However, it will be understood that
modifications and variations may be made to the disclosed version and
the invention is limited only by the scope of the following claims.
PHONOLA (PHILIPS) PNL6398/2 TIMER EATON P55 Multiple electrical connections for mechanical timers.
Multiple electrical connections for cam-type mechanical timers, which
are suitable to enable the outward connectors, or terminals, (26) to be
organized in the terminal board as required and the electrical
connection to be made with insulated electrical leads (15-115), the
organization of the outward connectors being embodied with
circuit-holder plates (16-17) in which the plates (16) for the power
connections contain circuits (18) made of sheared sheet metal and
comprising protruding angled shoes (20), which are correlated with the
metallic edge (25) of holes (19-24) included in the plates (16-17)
cooperating together.
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1. Multiple electrical connections for cam-type mechanical
timers, which are suitable to enable the outward connectors, or
terminals, (26) to be organized in the terminal board as required and
the electrical connection to be made with insulated electrical leads
(15-115), the organization of the outward connectors being embodied with
circuit-holder plates (16-17) in which the plates (16) for the power
connections contain circuits (18) made of sheared sheet metal and
comprising protruding angled shoes (20), which are correlated with the
metallic edge (25) of holes (19-24) included in the plates (16-17)
cooperating together.
2. Multiple electrical connections for cam-type
mechanical timers, which are suitable to enable the outward connectors,
or terminals, (26) to be organized in the terminal board as required and
the electrical connection to be made with insulated electrical leads
(15-115), the organization of the outward connectors being embodied with
circuit-holder plates (16-17) in which the plates (16) for the power
connections contain circuits (18) made of sheared sheet metal and
comprising transit holes (19) and protruding angled shoes (20), which
cooperate at least with sidewalls (21) of terminals (11) protruding from
the mechanical timer (10).
3. Multiple electrical connections as claimed in
Claim 1 or 2, in which the holes (19-24) have a rectangular plan.
4. Multiple electrical connections as claimed in
Claim 1 or 2, in which the holes (19-24) have a T-shaped plan.
5. Multiple electrical connections as claimed in any
claim hereinbefore, in which the holes (19-24) comprise at least one
notch (27) able to accommodate an end (114) of an electrical cable
(115).
6. Multiple electrical connections as claimed in any
claim hereinbefore, in which the various metallic items (11-20-114)
protruding from the same hole (24) are soldered to the metallic edge
surrounding that hole (24).
Description:
"MULTIPLE ELECTRICAL CONNECTIONS FOR MECHANICAL TIMERS"
This
invention concerns multiple electrical connections located downstream
of a mechanical programmer device. The programmer devices with which the
invention is concerned are normally called "timers" and have the
purpose of conditioning in sequences whic
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h can be chosen as desired the
functions proper to a machine or device with which such timers are
associated.
The timers can control and govern multiple functions at one and the same time.
The
invention is concerned preferably, but not only, with timers employed
in washing and drying machines for household, community or industrial
use.
From an actual timer itself there departs a plurality of
terminals the departure position of which is governed by the axial
assembly of the various cams and relative contact-holder supports, which
form the storage means of the timer itself.
A correct design can
organize only partly the rational arrangement of such terminals in view
of the circumferential sequence of the activations.
Moreover,
every person who has to apply such apparatus must have the usage means
organized in the terminal board which groups and arranges in order the
terminals in an individualized manner so as to facilitate the assembly,
maintenance, connections, etc.
Furthermore, every person applying
such apparatus requires that between the exit of the contact from the
timer and the corresponding exit in the individualized terminal board
there may be specific applications which have an effect on, or arise
from, the signal passing through such contact.
Besides, some
outward connectors or terminals serve to provide distribution and
governing signals, whereas other connectors or terminals serve to feed,
even if only momentarily, electrical power suitable to operate motors,
solenoid valves, electrical resistors, etc.
For this reason plates
are normally fitted in association with the timer which are suitable to
connect in a logical manner the semi-random outward connectors from the
timer to the organized and individualized outward connectors required
in the terminal board.
When such plates are fitted to the timer,
problems are raised with regard to electrical connections and to the
continuity of such connections in the long term.
Problems
concerning capacity are also raised as the normal printed circuits are
not always able to withstand the electrical power loads required by the
usage means.
Moreover, problems are involved with regard to the
assembly, assembly work, the quality of the joint and the stability of
the joint in the long term.
The more it is necessary to arrange to
perform such operations wholly or partly in an automatic manner, the
more serious these problems regarding the assembly and joints become.
The
plates are embodied at the present time by means of printed circuits
and may be assembled with the timer singly or more than one in number.
Such known embodiment does not meet the requirements of speed, quality and retention of quality in the long term.
The
present applicant has designed, tested and embodied this invention so
as to overcome the above drawbacks and obtain a rational, individualized
organization of the outward connectors in correspondence with the
terminal board.
According to the invention a wafer plate is
provided in cooperation with the outward leads from the timer; but by
wafer plate is meant a plate with at least the power circuits made of
sheared sheet metal and cooperating with a support plate.
Such sheared metal circuits may be applied to the support plate or sunk therewithin by fusion.
The support plate is made of a plastic material and performs support and insulation functions.
Such
wafer plate may itself bear the organized outward connectors of the
terminal board, or else the outward connectors of the terminal board may
be positioned on another plate, for instance a printed circuit plate.
According
to the invention the outward connectors from the timer and the
connecting shoes provided in the sheared metal circuit cooperate
mutually by sliding against each other so as to obtain, above all, a
stable mechanical contact.
According to a variant a plate is
provided which bears printed circuits suitable to act as means to
transfer control and governing signals.
A variant of the invention
a
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rranges for wafer plates comprising more than one circuit made of
sheared sheet metal, each set of circuits lying on different planes.
A further variant of the invention provides for a plate bearing printed circuits and circuits made of sheared sheet metal.
The
invention is therefore embodied with multiple electrical connections
for cam-type mechanical timers, which are suitable to enable the outward
connectors, or terminals, to be organized in the terminal board as
required and the electrical connection to be made with insulated
electrical leads, the organization of the outward connectors being
embodied with circuit-holder plates in which the plates for the power
connections contain circuits made of sheared sheet metal and comprising
protruding angled shoes, which are correlated with the metallic edge of
holes included in the plates cooperating together.
The attached
figures, which are given as a non-restrictive example, show the
following:- Fig.1 shows in a disassembled condition a connection
according to the invention; Fig.2 shows a disassembled variant of the
connection; Figs.3 to 7 show sections of possible types of connection
according to the invention.
A timer 10 comprises a terminal 11
containing a hole 12. One timer 10 includes a plurality of terminals 11,
all of which are located on a surface 13 of the timer 10.
Such terminals 11 may be aligned or be positioned on one or more lines along the length of the timer 10.
The
position of the terminals 11 will depend on the position of the
mechanical storage means (cam), on the angular position of the storage
means and on the sequence arrange
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d.
The hole 12 is suitable to
cooperate with an end 14 of a lead 15 without its sheath. Such leads 15
can be used to create bridges, auxiliary connections, branches, etc. by
connecting together the terminals 11 or outward connectors leaving the
timer 10 and by making use of the holes 12.
Wafer plates 16 and,
possibly, printed circuit plates 17 cooperate with the terminals 11. The
wafer plates 16 are obtained by sinking sheared sheet metal circuits 18
therein as in the example shown.
The wafer plates 16 may be
obtained also by applying such sheared sheet metal circuits 18 to
appropriate plates comprising suitable positioning and clamping means.
The
wafer plates 16 serve advantageously to convey electric power to usage
means requiring such power, such as motors, resistors, solenoid
valves,etc.
The wafer plates 16 contain a plurality of through
holes 19 passing therethrough. Such holes 19 cooperate directly with the
terminals 11 and therefore are present in at least the same number as
the terminals but may be included in a greater number, as we shall see
later.
The holes 19 are included for the passage of the terminals
11 or the ends 114 of a cable 115; if the terminals or cable are not
comprised, then the holes 19 may be missing.
The circuits 18 in
correlation with the holes 19, which, as said above, may be present not
as through holes as such but only as outward passages, comprise shoes 20
folded so that they can be positioned with a desired angle in relation
to the wafer plate 16.
It is therefore possible to fit the wafer
plate 16 to the surface 13 of the timer 10 so that the terminals 11
cooperate with the respective holes 19, which will be shaped suitably to
receive the terminals 11.
In this way a sidewall 21 of the
terminal 11 cooperates with, by sliding against and slightly altering
the trim of, a face 22 of the shoe 20 made in the circuit 18.
A mechanical and electrical contact in the form of a "T" is thus created between the terminal 11 and the shoe 20.
As
the terminal 11 is produced by shearing, its sidewalls 21 will have
their own specific consequent roughness, which cooperates with the
surface 22 of the shoe 20 in improving the contact.
A wafer plate
16 contains within itself a plurality of single circuits 18, with which
it is possible to produce bridges between the terminals
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11, auxiliary
connections, branches, etc.
At a desired position, in the terminal
board for instance, the circuits 18 are arranged in the required
organized form and may comprise a plurality of their own terminals or
outward connectors 26. One single circuit 18 may comprise one or more
terminals or outward connectors 26.
If the wafer plate 16 is not
enough to obtain all the connections, it is possible according to the
invention to provide also at least one printed circuit plate 17.
The
printed circuit plate 17 will contain a coordinated series of holes 24,
which are surrounded by a metallic edge 25 that is helpful for
soldering purposes.
Depending on the type of connection to be
produced, the metallic edge 25 will be connected electrically, that is
to say, it will form an integral part of one single printed circuit 23,
or will not be connected electrically to one single printed circuit 23.
A
printed circuit plate 17 cooperating with a wafer plate 16 will contain
as many holes 24 as there are shoes 20, and the positioning of the
holes and shoes will coincide and be reciprocal.
Thus there will
be holes 19-24 cooperating with terminals 11, and there will be shoes 20
and holes 24 cooperating with each other.
The holes 24 which have
to cooperate also with the terminals 11 will be T-shaped so that they
can accommodate the terminal 11 as well as the shoe 20.
If the
holes 24 have to cooperate only with the shoes 20, their conformation
will be such as to accommodate the shoe 20,
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which passes through the
support plate 17 and substantially protrudes therefrom.
It may
happen that the number of connections to be provided will be such as to
make insufficient the use of the leads 15, the wafer plates 16 and the
printed circuit plates 17.
It may also become necessary to be able
to make auxiliary connections after the timer 10 and the wafer and
support plates 16-17 have been assembled.
In such cases the
conformation of the hole 24 in the support plate and possibly also of
the hole 19 in the wafer plate may be altered to provide one or more
notches 27 able to accommodate the sheathless end 114 of the cable 15.
Such end 114 cooperates also with one of the two end surfaces 28 of the
terminal 11 and is suitable to protrude substantially from the support
plate 17.
Fig.3 shows a section of the connection which takes place between the terminal 11, circuit 18 and metallic edge 25.
The
final connection between the terminal 11, shoe 20, metallic edge 25 and
cable 114 or between two or more of the same, that is, between the
various metallic items protruding from the same hole 24 or connection
point, is made stable by means of soldering.
The conformation obtained enables the soldering to be produced in a soundwave bath and therefore in an automatic manner.
Fig.4 shows the case of an electrical connection made only between a wafer plate 16 and a printed circuit plate 17.
Fig.5 shows an example where a printed circuit 23 is produced on the wafer plate 16.
Fig.6 shows a case where two separate wafer plates 16 are employed.
Fig.7 shows an example of a wafer plate 16 consisting of two sets of sheared metal circuits.