U.S. patent number 3,852,558 [Application Number 05/455,158] was granted by the patent office on 1974-12-03 for magnetically coupled control for cooking platform.
This patent grant is currently assigned to Westinghouse Electric Corporation. Invention is credited to William A. English, Earl W. McCleerey.
United States Patent |
3,852,558 |
McCleerey , et al. |
December 3, 1974 |
MAGNETICALLY COUPLED CONTROL FOR COOKING PLATFORM
Abstract
A magnetically coupled type of control for a cooking platform
has a movable support member for the magnetic follower in which the
support member has a rack gear on one side for engagement with a
rotatable pinion gear on a shaft of the thermal cycling switch, and
with the other side of the support member having a channel
receiving the straight portion of a guide bar and a pair of
opposite open-ended slots to accommodate the ends of the guide bar
in the rectilinear movement of the support member, with the secured
ends of the guide bar serving as opposite end limits to movement of
the support member.
Inventors: |
McCleerey; Earl W.
(Monroeville, PA), English; William A. (Export, PA) |
Assignee: |
Westinghouse Electric
Corporation (Pittsburgh, PA)
|
Family
ID: |
23807630 |
Appl.
No.: |
05/455,158 |
Filed: |
March 27, 1974 |
Current U.S.
Class: |
219/622;
336/DIG.2; 219/660; 126/211; 338/12 |
Current CPC
Class: |
F24C
7/082 (20130101); Y10S 336/02 (20130101) |
Current International
Class: |
F24C
7/08 (20060101); H05b 005/08 () |
Field of
Search: |
;219/10.49,10.75,10.77,10.79 ;338/12 ;335/205,206 ;336/DIG.2
;126/211 ;310/103 ;337/101 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Reynolds; Bruce A.
Attorney, Agent or Firm: Arenz; E. C.
Claims
We claim:
1. In a magnetically coupled type of control arrangement for a
cooking platform having a heat producing element:
a user-operated control member on the accessible side of a control
panel;
a follower member on the other side of said panel adapted to be
magnetically coupled to said control member;
a support plate spaced from said other side of said panel;
a controller for controlling energization of said heat producing
element mounted to said support plate and including a rotatable
shaft projecting therefrom and having a pinion gear fixed
thereon;
a guide bar mounted at its ends on said plate and having a straight
length extending on both directions beyond said gear; and
a support member for said follower member having a gear rack on one
side for engagement with said pinion gear, and provided with a pair
of opposite, open-ended slots on the opposite side to accommodate
the ends of said guide bar in the rectilinear movement of said
support member, said guide bar ends serving as opposite end limits
to movement of said support member.
2. In an arrangement according to claim 1 including:
means for mounting said follower member on said support member to
constrain movement of one relative to the other in a plane parallel
to said support plate while permitting relative movement in a
direction perpendicular to said plane.
3. In an arrangement according to claim 1 including:
means biasing said pinion gear and controller to a deenergized
position.
4. In an arrangement according to claim 1 wherein:
said support plate includes slot means for securing said support
plate in one of a number of longitudinally shifted positions to
facilitate proper registry of said control member with indicia on
said control panel.
5. In an arrangement according to claim 2 wherein:
said means for mounting said follower member on said support member
includes a pair of projecting posts on said follower member and two
pairs of post receiving bores on said support member, one pair of
said post receiving bores being laterally offset from the other
pair to permit alternative positioning of said follower member
relative to said support member.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains particularly to magnetically coupled
controls useful with counter-top cooking platforms.
2. Description of the Prior Art
The closest prior art of which we are aware is U.S. Pat. No.
3,711,672 in which a rack gear positioned between two pinion gears
moves with the magnetic follower, with the two pinion gears
controlling a potentiometer and an on/off switch in accordance with
their rotation. The arrangement of the subject invention is
considered an improvement thereover in several respects including
that of reduced cost and being adapted to use a thermal cycling
switch and a return spring arrangement. The subject arrangement is
also adapted for use on either the right or left end control panel
areas with the follower member being adapted to be positioned in
either one or another laterally separated locations during assembly
of the control to accommodate either a right or left-hand side
arrangement.
SUMMARY OF THE INVENTION
In accordance with our invention, the magnetically coupled control
includes a user-operated control member on the accessible side of a
control panel, a magnetic follower member on the other side of the
panel, a support plate adapted to support two individual controls,
an energization controller mounted to the support plate and having
a rotatable shaft carrying a pinion gear, a guide bar mounted at
its ends to the plate and having a straight length portion
extending in both directions beyond the pinion gear, a support
member for the follower including a rack gear on one side for
engagement with the pinion gear and having an oppositely disposed
channel-shaped section receiving the straight length of the guide
bar and a pair of opposite, open-ended slots accommodating the ends
of the guide bar in the rectilinear movement of the support member,
with the guide bar ends serving as opposite end limits to movement
of the support member, and means for mounting the follower member
on the support member to constrain movement of one relative to the
other in a plane parallel to said support plate while permitting
relative movement in a direction perpendicular to that plane.
DRAWING DESCRIPTION
FIG. 1 is a partly broken plan view of a cooking platform provided
with a control arrangement according to the invention;
FIG. 2 is a side elevational view, partly broken and sectioned of a
control arrangement according to the invention, with the support
and follower member being shown in one extreme position in solid
lines, and in an opposite extreme position in broken lines; and
FIG. 3 is an exploded isometric view, partly broken and sectioned,
to illustrate details of the arrangement.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIG. 1, the cooking platform as viewed from above
essentially comprises a generally perimetric frame 10 of relatively
thin, substantially non-magnetic material such as aluminum or a 300
series stainless steel, with a glass ceramic plate 12 occupying a
central opening of the frame and provided with visual indicia 14
for indicating the cooking areas and underlying locations of the
heat producing elements 16. The user-operated control member 18 for
each cooking area is located in a control area 20 of the control
panel at the right and left-hand sides of the frame 10.
An individual control system is provided for each of the cooking
areas. Each control system includes the control member 18 on the
upper or accessible side of the control panel, a follower member 22
on the under or other side of the control panel, a support member
generally designated 24 upon which the follower member carriage 22
is seated, a guide bar generally designated 26 secured at its
opposite ends to a support plate 28, and an energization controller
such as a thermal cycling switch mounted to the plate and having a
pinion gear 30 on the upwardly projecting shaft of the thermal
cycling switch.
As may be best seen in FIG. 1, a single support plate 28 is
provided for each of the control panels at the right and left-hand
sides of the frame, and two individual control assemblies are
associated with each of the support plates. The support plate is
provided with slotted holes 36 at those locations at which the
plate is secured to a supporting box 34 (FIG. 2). This permits the
support plate to be shifted longitudinally before securement to
obtain correspondence between the control energization level
indicia 37 on the control panel and the position of the underlying
control mechanism. It will also be noticed from FIG. 1 that the
support plate 28 and the individual control assemblies are not in
mirror image relationship to each other on the right and left-hand
sides, but rather that any given support plate with the control
assemblies may be used on either the right or left-hand side
without turning them end for end. This is possible with the
arrangement according to the invention because the follower member
22 may be shifted laterally on the support member to either of two
alternate positions, as will be further explained later.
Referring to FIGS. 2 and 3, the control member 18 and the follower
member 22 may be of the same general structure and have magnetic
blocks therein as described in the noted U.S. Pat. No. 3,711,672.
As there taught, as the control member is moved along the control
panel 20 in the direction indicated by the arrows in FIG. 3, the
follower member 22 will correspondingly be moved in the same
direction with the wheels 32 of the carriage of the follower member
riding against the underface of the panel.
The support member 24, upon which the follower member seats, is
formed of two separate plastic parts, an upper part 38 and a lower
part 40 which are coextensive in length. The upper part includes a
block 42 with two pairs of bores formed therein, with the one pair
44 being laterally offset from the other pair 46. As seen in FIG.
3, a pair of downwardly projecting posts or bosses 48 on the
underside of the follower member 22 are adapted to be received in
either one or the other pairs of the bores, depending upon whether
the control assemblies are at the right-hand or the left-hand side
of the cook top. In either case, the posts are received in those
bores which are toward the outer side of the cook top. Thus, in
FIG. 3, the posts are received in the bores 46 indicating that this
is the left side of the cook top. The posts are loosely received in
the bores so that, while the follower may move upwardly relative to
the block 42, lateral movement of the follower relative to the
block 42 is not permitted. This arrangement permits the carriage to
move up solidly against the underside of the control panel when the
control member 18 is in place.
Both the upper and lower parts 38 and 40 of the support member are
molded acetal plastic parts to provide low friction contact
surfaces. The lower part 40 includes a rack gear 50 along one side
and includes a base flange 52 on its other side provided with two
opposite, open-ended slots 54 with an intermediate web or land 56.
These opposite, open-ended slots in the base flange portion of the
support member accommodate the right angle end portions 58 of the
guide bar 26 during the rectilinear movement of the support member
from one extreme position to the other, with the end portions
serving as stops for the support member when the land 56 abuts the
end portions 58 of the guide bar.
The underface of the top part 38 of the support member is provided
with a downwardly open channel which seats upon the top face of the
lower part 40 of the support member in the assembled relation of
these parts. These parts 38 and 40 are held together in their
assembled relation by the screws 60 and nuts 62.
With the upper and lower parts 38 and 40 of the support member
assembled, the straight length portion 26 of the guide bar is in
effect captured in the channel-shaped space 64 on the one side of
the support member, with the other side of the support member being
held in position by the engagement of the pinion gear 30 with the
rack gear 50.
The thermal cycling switch 66 may be of the general type shown in
either U.S. Pat. No. 2,813,173 or 3,634,802, these being
conventional switches for controlling energization of heating
elements and are sometimes referred to as infinite switches. The
upwardly projecting D-shaped shaft 68 of the infinite switch
receives the pinion gear 30 thereon and a spiral return spring 70
is provided with one end attached to the pinion gear and the other
end attached to the support plate 28. Thus, as the pinion gear is
rotated in the direction of the arrow in FIG. 3 by the movement of
the support member 24, the return bias of the spring 70 is
increased. However, the return force of the spring is not
sufficient to overcome the friction between the control member 18
and the top panel created by the magnetic attraction between the
control member and the follower member. However, if the control
member 18 is removed from the control panel, the return spring will
rotate the pinion gear and infinite switch shaft in a clockwise
position, forcing the support member 24 back to the extreme
position shown in FIG. 3. This, of course, corresponds to the
infinite switch being in an Off position and deenergization of the
heating element.
The arrangement as described results in a relatively low friction
load so that, if the magnetic coupling is broken by removing the
control member 18, the parts will return to the Off position. The
low friction load exists because the guide bar 26 offers relatively
little resistance to movement of the support member 24, and the fit
of the support member to the guide bar and the pinion gear 30 is
relatively loose. Also, the thermal cycling switch has a relatively
low internal friction as contrasted to a potentiometer.
The relatively loose seating of the carriage on the support member
permits the carriage to rise slightly in its magnetically coupled
relation to the control member to compensate for manufacturing
tolerances in the vertical spacing between the support plate and
the control panel.
In the assembly of the parts, the thermal cycling switch 66 is
oriented to an Off position by the location of the flat on the
D-shaped shaft and with the spring 70 in a preloaded condition
before the rack gear 50 of the support member 24 is engaged with
the gear 30. With one end of the guide bar 26 loosened, the support
member 24 is moved to the extreme position at which the land 56
abuts the other end 58 of the guide bar as shown in FIG. 3, and the
support member is then swung to place the rack gear into engagement
with the pinion gear. Then, the loose end of the guide bar is moved
over and secured to hold the engagement between the rack gear and
the pinion gear. The slotted holes 36 in the support plate 28
permit the final adjustment of the support plate 28 to be made to
provide the proper registry between the switch Off postion and the
position of the control member 18 on the control panel 20.
The arrangement, which permits the shifting of the carriage 22
laterally to either the one pair of bores 44 or the other pair 46,
accommodates the lateral registry of the control assembly with the
control member 18 at either side. This is considered advantageous
in connection with proposed standards which require a minimum
distance from the edge of any heating element to the location of
any control element.
* * * * *