U.S. patent application number 10/323048 was filed with the patent office on 2004-06-17 for dishwasher door balancing system.
This patent application is currently assigned to Maytag Corporation. Invention is credited to Raches, Scott D..
Application Number | 20040113531 10/323048 |
Document ID | / |
Family ID | 32507305 |
Filed Date | 2004-06-17 |
United States Patent
Application |
20040113531 |
Kind Code |
A1 |
Raches, Scott D. |
June 17, 2004 |
Dishwasher door balancing system
Abstract
A kitchen or household appliance such as a dishwasher includes a
base portion, a door hingably connected to the base portion, a cord
operatively connected to the door, an extension spring operatively
connected to the cord and the base portion to partially balance
opening of the door by exerting a force on the cord and the door, a
damping pulley positioned along the cord between the extension
spring and the door to further balance opening of the door by
providing resistance to motion of opening the door without manual
adjustment.
Inventors: |
Raches, Scott D.; (Jackson,
TN) |
Correspondence
Address: |
MCKEE, VOORHEES & SEASE, P.L.C.
ATTN: MAYTAG
801 GRAND AVENUE, SUITE 3200
DES MOINES
IA
50309-2721
US
|
Assignee: |
Maytag Corporation
Newton
IA
|
Family ID: |
32507305 |
Appl. No.: |
10/323048 |
Filed: |
December 17, 2002 |
Current U.S.
Class: |
312/319.2 |
Current CPC
Class: |
A47L 15/4261 20130101;
E05Y 2900/304 20130101; E05F 1/1075 20130101 |
Class at
Publication: |
312/319.2 |
International
Class: |
A47B 088/00 |
Claims
What is claimed is:
1. A kitchen appliance, comprising: a base portion; a door hingably
connected to the base portion; a cord operatively connected to the
door; an extension spring operatively connected to the cord and the
base portion to partially balance opening of the door by exerting a
force on the cord and the door; a damping pulley positioned along
the cord between the extension spring and the door to further
balance opening of the door by providing resistance to motion of
opening the door without manual adjustment.
2. The kitchen appliance of claim 1 further comprising a flange in
operative contact with the damping pulley to provide resistance to
motion of opening the door.
3. The kitchen appliance of claim 2 wherein the flange is a spring
flange for engaging a perimeter surface of the damping pulley.
4. The kitchen appliance of claim 2 wherein the flange engages a
side-wall of the damping pulley.
5. The kitchen appliance of claim 1 wherein the force is an
inwardly directed force.
6. The kitchen appliance of claim 1 wherein the kitchen appliance
is a dishwasher.
7. The kitchen appliance of claim 1 wherein the cord is
stranded.
8. The kitchen appliance of claim 1 wherein the damping pulley
includes a plurality of teeth.
9. The kitchen appliance of claim 8 wherein the cord includes a
plurality of catch members.
10. The kitchen appliance of claim 9 wherein the catch members are
beads.
11. The kitchen appliance of claim 1 wherein the cord is wrapped
completely around the pulley to reduce slippage.
12. A door balancing system for a dishwasher having a cabinet and a
door, the door balancing system, comprising: an extension spring
operatively connected to the cabinet; a cord operatively connected
to the extension spring and to the door; a pulley engaging the cord
between the extension spring and the door such that the extension
spring provides a first force to balance opening of the door and
the pulley resists motion of opening the door to further balance
opening of the door.
13. The door balancing system of claim 12 further comprising a
flange in operative contact with the pulley to provide resistance
to motion of opening the door.
14. The door balancing system of claim 13 wherein the flange is a
spring flange for engaging a perimeter surface of the pulley.
15. The door balancing system of claim 13 wherein the flange
engages a side-wall of the pulley.
16. The door balancing system of claim 12 wherein the pulley
includes a plurality of teeth.
17. The door balancing system of claim 12 wherein the cord is
wrapped completely around the pulley to reduce slippage.
18. A front-loading dishwasher having a cabinet and a door
operatively connected to the cabinet, comprising: an extension
spring operatively connected to the cabinet to provide a force for
partially counterbalancing weight of the door; a cord operatively
connected between the extension spring and the door; a damping
pulley positioned along the cord to provide resistance to motion of
opening of the dishwasher door such that the door opens in a
controlled manner without a manual adjustment to alter the force
provided by the extension spring.
19. The dishwasher of claim 18 further comprising a flange in
operative contact with the damping pulley to increase resistance to
the motion of opening the door.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to household appliances, including,
but not limited to dishwashers. More specifically, this invention
relates to a system for balancing the door of the household
appliance.
[0002] In household or kitchen appliances, such as dishwashers, it
is desirable to have proper door balance. When there is proper door
balance, the door can open in a smooth, controlled motion. It is
desirable for an operator to open the door to the desired level
with no sudden fall of the door or tendency for the door to spring
back up from an open position. Manufacturers have attempted to
provide proper door balance by manually adjusting the balance of
dishwasher doors.
[0003] Adjustment of a dishwasher door is a burden to dishwasher
manufacturers. Based on different model features (such as, but not
limited to the control type, the presence of sound dampers, the
material weight, or other variations) the weight of the dishwasher
doors will vary. Therefore, in order to provide for proper
balancing, each door assembly requires a specific counterbalance
force to provide proper adjustment. If there is improper
adjustment, a front-loading door can fall hard to a noisy and
abrupt stop in the horizontal position, or the door may not sit
horizontal without the operator having to physically push the door
down to the fully open position. Thus, improper adjustment is a
nuisance to the consumer. In particular, improper adjustment of a
dishwasher door is believed to result in a poor quality perception
by consumers of the dishwasher.
[0004] In dishwashers, a set of extension springs are typically
used for providing proper door balance. Then, each extension spring
can be manually adjusted for each dishwasher model in order to
provide for proper balancing. One problem is that this adjustment
process is labor-intensive, and thus can be cost prohibitive.
[0005] Another attempt is a system wherein a stranded rope runs
through a groove in a fixed plastic part to generate friction for
restricting door motion. One problem with such an approach is that
the stranded rope can wear and break during normal use due to the
wear resulting from friction. A broken rope can result in a service
call.
[0006] Therefore, a primary object of the present invention is the
provision of an improved household or kitchen appliance, such as a
dishwasher.
[0007] A further object of the present invention is the provision
of a dishwasher door that provides for proper adjustment without
requiring a manual adjustment process.
[0008] A further object of the present invention is the provision
of a dishwasher having a door balancing system that provides for
smooth, controlled motion of the door.
[0009] Yet another object of the present invention is the provision
of a dishwasher door balancing system that provides consumers with
a high quality perception of the dishwasher.
[0010] A further object of the present invention is the provision
of a dishwasher door balancing system that allows for variance in
the weight of the dishwasher door.
[0011] Yet another object of the present invention is the provision
of a dishwasher door balancing system that uses frictional force
without causing undue wear on the dishwasher.
[0012] These and/or other objects, features, or advantages of the
present invention will become apparent from the specification and
the claims that follow.
SUMMARY OF THE INVENTION
[0013] The present invention relates to a kitchen or household
appliance having a door, such as, but not limited to a dishwasher.
The present invention provides for proper balancing of a dishwasher
door without requiring manual adjustment of springs or other manual
adjustments to compensate for the weight of the particular
dishwasher door.
[0014] According to one embodiment of the present invention, a
kitchen appliance includes a base portion, a door hingably
connected to the base portion, a cord operatively connected to the
door, an extension spring operatively connected to the cord and the
base portion to partially balance opening of the door by exerting a
force on the cord and the door, and a damping pulley is positioned
along the cord between the extension spring and the door to further
balance opening of the door by providing resistance to motion of
opening the door without manual adjustment. The extension spring
counterbalances most of the door weight. Then, to account for
variance in door weight for different models, the damping pulley
system resists motion of the opened dishwasher door. In the damping
pulley system, friction is applied to resist rotation at the
pulley. The present invention provides for applying the friction in
various ways. Also, the pulley can include teeth to prevent the
slippage of the cord. For example, a flange in operative contact
with the damping pulley can provide resistance to motion of opening
the door. The flange can be a piece of spring steel that engages a
perimeter surface of the damping pulley. The flange can engage a
side-wall of the pulley to provide resistance to motion of opening
the door.
[0015] According to another aspect of the present invention, the
present invention provides for a door balancing system for a
dishwasher having a cabinet and a door. The door balancing system
includes an extension spring operatively connected to the cabinet,
a cord operatively connected to the extension spring and the door,
and a pulley engaging the cord between the extension spring and the
door such that the extension spring provides a first force to
balance opening of the door and the pulley resists motion of
opening the door to further balance opening of the door.
[0016] According to another aspect of the present invention, a
front-loading dishwasher is provided. The front-loading dishwasher
has a cabinet and a door operatively connected to the cabinet and
includes an extension spring operatively connected to the cabinet
to provide a force for partially counterbalancing weight of the
door, a cord operatively connected between the extension spring and
the door, a damping pulley positioned along the cord to provide
resistance to motion of opening of the dishwasher door such that
the door opens in a controlled manner without a manual adjustment
to alter the force provided by the extension spring. The dishwasher
can include a flange in operative contact with the damping pulley
to increase resistance to the motion of opening the door.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a perspective view of a dishwasher.
[0018] FIG. 2 is a side view of the bottom portion of a dishwasher
with the door closed and having a door balancing system with a
toothed pulley according to one embodiment of the present
invention.
[0019] FIG. 2A is a view similar to FIG. 2, except with the door
open.
[0020] FIG. 3 is a side view of a dishwasher door balancing system
according to another embodiment of the present invention.
[0021] FIG. 4 is a side view of a dishwasher door balancing system
according to another embodiment of the present invention.
[0022] FIG. 5 is a side view of a dishwasher balancing system
according to another embodiment of the present invention.
[0023] FIG. 6 is a front view of the pulley of the door balancing
system taken along lines 6-6 of FIG. 5.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The present invention provides for balancing the weight of
doors of a kitchen or household appliance such as a dishwasher.
FIG. 1 illustrates a dishwasher 10. The dishwasher 10 includes a
dishwasher door 12 and a dishwasher base portion 14. The dishwasher
door 12 is hingably connected to the dishwasher base portion 14,
such as along a bottom portion of the dishwasher base portion 14.
The dishwasher 10 shown is a front-loading dishwasher with the door
12 opening outwardly and downwardly.
[0025] FIG. 2 provides a side view of the bottom portion of the
dishwasher 10. In FIG. 2, the dishwasher door 12 is hingably
connected to the dishwasher base portion 14 at the door hinge 16. A
stranded rope, cable or other type of cord 18 is also operatively
connected to the dishwasher door 12 in any convenient manner. For
example, as shown in the drawings, the forward end of the cord 18
includes a bead or loop, which is received in a notch 32 of an
inwardly extending arm 30 of the door 12. The rearward end of the
cord 18 is connected to an extension spring 26 that is connected to
the dishwasher base portion 14. A pulley 20 is located between the
extension spring 26 and the dishwasher door 12. The cord 18 is in
operative contact with the pulley 20. The pulley 20 rotates in the
direction indicated by arrow 28. The pulley 20 can include a
plurality of teeth 22 that may be molded into the pulley 20. The
pulley 20 is pivotal about a pivot 36, which can be a shoulder
bolt. The cord 18 can include catch members such as over molded
beads or swaged ferrules 24 that matingly contact between the teeth
22 of the pulley 20. This restricts the motion of the cord 18 in
order to reduce or eliminate slippage. Other types of catch members
can be used so that the cord 18 can matingly contact with the teeth
22 of the pulley 20 in order to allow smooth opening of the
dishwasher door 12.
[0026] The positioning of the cord 18 as shown allows the extension
spring 26 to exert an inwardly directed force on the cord 18 to
provide resistance to the motion of opening the dishwasher door 12.
FIG. 2A illustrates the dishwasher door 12 in an open position with
the extension spring 26 expanded.
[0027] FIG. 3 shows another embodiment of the present invention. In
FIG. 3, the cord 18A is wrapped around the pulley 20. Wrapping the
cord 18A completely around an outer flange 27 of the pulley 20
reduces or eliminates slippage, since there are no beads on the
cord 18A.
[0028] The damping system for the pulley 20 can be provided in
different manners. For example, in FIG. 4, a steel spring flange 34
is in operative contact with the pulley 20 in order to exert a
friction force on the perimeter edge 27 of the pulley 20. The steel
spring flange 34 can be operatively connected to the dishwasher
base portion 14 with a support member 38. The steel spring flange
34 provides friction such that the pulley resists the motion of
opening the door to further balance opening of the door.
[0029] Another embodiment of the present invention is shown in
FIGS. 5 and 6. In FIGS. 5 and 6, a spider-like steel compression
spring 44 is mounted behind pulley 20 at the pivot 36. The spring
44 has multiple legs 48, each having a substantially flat flange 42
in operative contact with a flat surface 46 of the pulley 20. This
contact exerts a frictional force on the pulley 20 to smooth the
motion of opening the door. In FIG. 6, the pivot 36 consists of a
shoulder bolt to pivotally connect the pulley to the dishwasher tub
support 40 of the dishwasher base portion 14. Although the present
invention contemplates other manners of providing frictional force
for providing balancing, preferably friction is not applied in a
manner that will create undue wear and increase the need for
servicing.
[0030] Thus, a kitchen or household appliance, such as a
dishwasher, has been disclosed that has an extension spring to
balance weight of the kitchen appliance door and is adapted for
balancing without manual adjustment of the extension spring. The
present invention contemplates that one or more extension springs
and/or damping pulleys can be used. For example, the present
invention contemplates that two sets of damping pulleys and
extension springs can be used on opposite sides of a dishwasher.
The present invention also contemplates variations and equivalents
in the manner in which the pulley is dampened. These and other
variations and equivalents are within the spirit and scope of the
present invention.
* * * * *