U.S. patent application number 11/401374 was filed with the patent office on 2007-01-18 for manually driven bathtub lift.
Invention is credited to Paul Ogrodnick.
Application Number | 20070011803 11/401374 |
Document ID | / |
Family ID | 37660269 |
Filed Date | 2007-01-18 |
United States Patent
Application |
20070011803 |
Kind Code |
A1 |
Ogrodnick; Paul |
January 18, 2007 |
Manually driven bathtub lift
Abstract
A manually driven bathtub lift for assisting persons of limited
strength or mobility into or out of a typical bathtub without the
high costs associated with pneumatic, hydraulic or electric lift
devices. A seat is attached to a wheeled trolley arranged for
movement up an inclined track mounted on a base frame. A chain is
disposed about a drive sprocket and a set of guide pulleys and
attached to opposite ends of the trolley. The set of pulleys
includes an idler that is biased to retain tension in the chain.
The drive sprocket is driven by the rotation of a driver wheel
supported on the same shaft as the sprocket. Rotation of the
sprocket drives the chain which in turn moves the trolley and
attached seat. The driver wheel has handles circumferentially
spaced around it and is of large enough size that it can be reached
and operated from the seat. The lift is light to allow for easily
installation and removal and does not require significant strength
to operate.
Inventors: |
Ogrodnick; Paul; (Yorkton,
CA) |
Correspondence
Address: |
Ade & Company Inc.
1795 Henderson Highway
PO Box 28006
Winnipeg
MB
R2G 1P0
CA
|
Family ID: |
37660269 |
Appl. No.: |
11/401374 |
Filed: |
April 11, 2006 |
Current U.S.
Class: |
4/560.1 |
Current CPC
Class: |
A61G 7/1019 20130101;
A61G 7/1003 20130101; A61G 7/1059 20130101 |
Class at
Publication: |
004/560.1 |
International
Class: |
A47K 3/02 20060101
A47K003/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 15, 2005 |
CA |
2,512,220 |
Claims
1. A bathtub lift apparatus for assisting a person into and out of
a bathtub comprising: a base frame for being received in the tub,
the base frame including a track supported on the frame having a
lower end and an upper end; a trolley supported for movement along
the track; a seat for supporting the person thereon, the seat being
supported on the trolley device for movement with the trolley
between a lower position at the lower end of the track and an upper
position at the upper end of the track; a rotatable drive member
supported for rotation on the frame; an elongate driven member
engaged about the drive member and connected to the trolley for
displacement of said trolley as the drive member is rotated; and a
driver device for rotating the drive member.
2. The apparatus according to claim 1 wherein the base frame
comprises two laterally spaced parallel walls, wherein the drive
member and elongate driven member are located between said
walls.
3. The apparatus according to claim 1 wherein the track comprises
two laterally spaced track members, each having an upper and lower
surface defining an elongate channel therebetween for receiving the
trolley.
4. The apparatus according to claim 3 wherein each of the upper and
lower surfaces of the track members comprises a rail.
5. The apparatus according to claim 3 wherein the upper surface of
each track member comprises a rail and the lower surface of each
track member comprises the base frame.
6. The apparatus according to claim 1 wherein there are provided
roller members supported on each side of the trolley supported for
movement along the track.
7. The apparatus according to claim 6 wherein the roller members
are supported in pairs on axles mounted to the trolley.
8. The apparatus according to claim 1 wherein the track is
non-linear between the upper and lower ends thereof.
9. The apparatus according to claim 8 wherein the seat is pivotally
supported on the trolley for pivotal motion relative thereto.
10. The apparatus according to claim 9 wherein there is provided: a
pivotal mounting mechanism for pivotally supporting the seat on the
trolley for pivotal motion between the lower position where the
seat is generally horizontal and the trolley is inclined along the
track and a lifting position where the seat and trolley are both
inclined along the track and generally parallel to each other; and
an abutment member mounted on the seat that abuts with the trolley
to prevent the seat from pivoting passed the lifting position where
the seat and trolley are generally parallel.
11. The apparatus according to claim 1 wherein the elongate driven
member is an endless and flexible member.
12. The apparatus according to claim 1 wherein the elongate driven
member is guided by idler members supported on the base frame.
13. The apparatus according to claim 12 wherein one of the idler
members is floatingly supported on the base frame and biased in
order to maintain tension in the elongate driven member.
14. The apparatus according to claim 1 wherein the elongate driven
member comprises a chain and the driver member comprises a sprocket
for engaging the chain.
15. The apparatus according to claim 1 wherein the driver device
comprises a hand crank mechanism for rotating the drive member.
16. The apparatus according to claim 1 wherein the driver device
comprises a rotational member having a series of handles
circumferentially spaced therearound.
17. The apparatus according to claim 16 wherein the handles
comprise openings in the rotational member.
18. The apparatus according to claim 1 wherein the driver device is
accessible by the person supported in the seat.
19. The apparatus according to claim 1 wherein there is provided a
locking mechanism for selectively preventing motion of the seat
relative to the base frame.
20. The apparatus according to claim 19 wherein the locking
mechanism is coupled between the driver device and the base frame.
Description
[0001] The present invention relates to a mechanical bathtub lift
seat apparatus for assisting persons of limited mobility, such as
the elderly or disabled, transfer into or out of a typical
bathtub.
BACKGROUND
[0002] Persons having permanently limited mobility or strength to
due to age or disability may have difficulty performing certain
typical daily tasks. Entry to or exit from a bathtub is an example
of such a task, as it requires transition between a standing
position outside the tub and a seated position upon a very low
surface within the tub, including climbing over the side wall.
[0003] As a result, there are a number of existing products aimed
at assisting a user enter and exit the tub by easing the
aforementioned transition. These products include inflatable chairs
positioned within a bathtub for lowering and raising the user to
and from the bottom of the tub in a constantly seated position.
Other seat assemblies can be positioned within a tub for the same
purpose, but are driven by water actuated cylinders or electric
motors. Some of these assemblies feature rotating seats so that the
user can initially sit with his/her legs outside the tub and then
rotate their legs over the tub wall before being lowered,
eliminating the step of unassisted entry to the tub altogether.
Other devices, typically driven by electric motors, are capable of
actually transferring the user from a seated position entirely
outside the walls of the tub to a seated position within. One
lowering system involves a band spanning from a wall-mounted
dispenser on one side of a tub to the wall of the tub opposite the
dispenser. An electric motor within the dispenser slowly dispenses
more length of the band in order to lower a user seated on the band
into the tub. Once bathing is completed, the motor is run in an
opposite direction to retract the band into the dispenser, thereby
lifting the user back up to the top of the tub.
[0004] The primary problem associated with the existing bathtub
lift devices is the high cost involved. The need for components
such as air compressors, seals and adaptors for water driven
devices, electric motors and control systems, coupled with possible
installation costs, keeps many of these products financially out of
reach for many of those in need of the assistance that would be
provided. Many elderly or disabled persons live on limited income
and cannot justify the high cost of the existing bathtub lift
systems despite the comfort and safety levels they offer. As a
result, there is a need for a bathtub lift apparatus that can be
produced and sold at a reasonable cost.
SUMMARY
[0005] According to one aspect of the present invention there is
provided a bathtub lift apparatus for assisting a person into and
out of a bathtub comprising:
[0006] a base frame for being received in the tub, the base frame
including a track supported on the frame having a lower end and an
upper end;
[0007] a trolley supported for movement along the track;
[0008] a seat for supporting the person thereon, the seat being
supported on the trolley device for movement with the trolley
between a lower position at the lower end of the track and an upper
position at the upper end of the track;
[0009] a rotatable drive member supported for rotation on the
frame;
[0010] an elongate driven member engaged about the drive member and
connected to the trolley for displacement of said trolley as the
drive member is rotated; and
[0011] a driver device for rotating the drive member.
[0012] Preferably the base frame comprises two laterally spaced
parallel walls, wherein the drive member and elongate driven member
are located between said walls.
[0013] Preferably the track comprises two laterally spaced track
members, each having an upper and lower surface defining an
elongate channel therebetween for receiving the trolley.
[0014] Each of the upper and lower surfaces of the track members
may comprise a rail.
[0015] Alternatively, the upper surface of each track member may
comprise a rail while the lower surface of each track member
comprises the base frame.
[0016] Preferably there is provided roller members supported on
each side of the trolley supported for movement along the
track.
[0017] Preferably the roller members are supported in pairs on
axles mounted to the trolley.
[0018] Preferably the track is non-linear between the upper and
lower ends thereof.
[0019] The seat may be pivotally supported on the trolley for
pivotal motion relative thereto.
[0020] In this arrangement, preferably there is provided:
[0021] a pivotal mounting mechanism for pivotally supporting the
seat on the trolley for pivotal motion between the lower position
where the seat is generally horizontal and the trolley is inclined
along the track and a lifting position where the seat and trolley
are both inclined along the track and generally parallel to each
other; and
[0022] an abutment member mounted on the seat that abuts with the
trolley to prevent the seat from pivoting passed the lifting
position where the seat and trolley are generally parallel.
[0023] Preferably the elongate driven member is flexible.
[0024] The elongate driven member may be endless.
[0025] Preferably the elongate driven member is guided by idler
members supported on the base frame.
[0026] Preferably one of the idler members is floatingly supported
on the base frame and biased in order to maintain tension in the
elongate driven member.
[0027] Preferably the idler members comprise pulleys.
[0028] Preferably the elongate driven member comprises a chain and
the driver member comprises a sprocket for engaging the chain.
[0029] Preferably the driver device comprises a rotational member
having a series of handles circumferentially spaced
therearound.
[0030] In this arrangement, preferably the handles comprise
openings in the rotational member.
[0031] Alternatively, the driver device may comprise a hand crank
mechanism for rotating the drive member.
[0032] Preferably the driver device is accessible by the person
supported in the seat.
[0033] Preferably there is provided a locking mechanism for
selectively preventing motion of the seat relative to the base
frame.
[0034] Preferably the locking mechanism is coupled between the
driver device and the base frame.
[0035] Preferably the locking mechanism comprises:
[0036] an opening in the driver device;
[0037] a corresponding opening in the base frame;
[0038] a pin for passing through the opening in the driver device
into the opening in the frame, thereby blocking motion of said
driver device, and hence the driver member, elongate driven member,
trolley and seat, relative to said frame.
[0039] Preferably the base frame and the driver device comprise
aluminum.
[0040] The present invention can be made and sold at substantially
lower costs than existing bathtub lifts as a result of its simple
mechanical structure. Assembly is simple and affordable, as the
drive system not require any complex, costly or custom components
and the base frame is easy to fabricate. The apparatus is hand
driven and therefore does not require the use of an external power
source, such as an electric motor or air compressor and
corresponding control mechanism. Furthermore, the simplicity of the
apparatus ensures that any maintenance will be minimal and
affordable.
[0041] The driver device is reachable from the seat of the lift and
therefore may be used by a bather without outside assistance. The
driver device is of substantial size such that the amount of torque
needed to lift the bather supported on the seat can be achieved
with relatively little force. As a result, the bather does not
require a lot of strength to use the apparatus and is therefore
less likely to require assistance. Using a material of relatively
high strength to weight ratio such as aluminum to construct the
frame and driver device, the weight of the apparatus is kept to a
minimum so that the lift can be easily lowered into and lifted out
of a typical bathtub. This is ideal for the cases where more than
one person uses the tub on a regular basis and the lift is not
always needed. There is no need for professional installation,
which helps keep down the overall cost of the lift apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
[0042] In the accompanying drawings, which illustrate an exemplary
embodiment of the present invention:
[0043] FIG. 1 is a side elevational view of the bathtub lift with
the seat in the lowered position.
[0044] FIG. 2 is a side elevational view of the bathtub lift with
the seat in the raised position.
[0045] FIG. 3 is a rear elevational view of the bathtub lift with
the seat in the lowered position.
[0046] FIG. 4 is a rear elevational view of the bathtub lift with
the seat in the raised position.
[0047] FIG. 5 is a top plan view of the bathtub lift with the seat
in the lowered position.
[0048] FIG. 6 is a top plan view of the bathtub lift with the seat
in the raised position.
[0049] FIG. 7 is a cross sectional view of the bathtub lift with
the seat in the raised position as taken across line VII-VII of
FIG. 6.
DETAILED DESCRIPTION
[0050] The following description outlines the details of a bathtub
lift for assisting persons of limited mobility, such as the elderly
or disabled, transfer into or out of a typical bathtub. One
embodiment of the present invention is shown from the side in FIGS.
1 and 2. The bathtub lift apparatus 1 features a base frame 10 for
supporting the apparatus within the bathtub (not shown), a seat 20
for supporting the bather and a driver device 40 for controlling
motion of the seat 20. The lift functions in such a manner as to
move the seat 20 between a lower position as seen in FIG. 1 and a
raised or upper position as seen in FIG. 2. The seat 20 has a
backrest portion 21 and a bottom portion 22 connected by an angled
portion 23. The user can sit upon the bottom portion 22 in the
raised position from outside the tub, rotate his or her body in
order to dispose each leg on an opposite side of the apparatus and
then descend gradually to the lowered position within the tub. Once
finished bathing, the user can then use the control device 40 to
ascend back to the raised position and then rotate his or her legs
over the tub wall in order to exit the bathtub.
[0051] The movement of the seat is achieved through rolling motion
of a trolley 30 attached to the seat 20. The base frame 10 includes
a pair of spaced apart parallel vertical walls 11 each having an
upper edge 12 defining generally horizontal lower 17 and upper 18
portions and an inclined portion 16. The walls 11 are connected and
spaced apart at the end of the upper portion 16 by a horizontal
base member 13 at the bottom of the frame 10 and vertical end wall
15 disposed above the base member as shown in FIGS. 3 and 4. A
track assembly 50 is supported on each wall 11. The track includes
a rail 51 which is held above the base frame 10 by rail supports 52
that extend generally perpendicular to the upper edge 12 of the
walls 11. The rail 51 and supports 52 are connected by bolts 53 in
order to form a channel 54 defined by a space between the rail 51
and the upper edge 12 of the wall 11. This channel 54 defines the
path along which the trolley 30 can move. The trolley includes
wheels 32 disposed on each side of the trolley body 31 for rolling
motion within the channel 54. The track extends along the inclined
16 and upper 18 portions of the upper edge 12 so that the seat 12
attached to the rear end of the trolley 30 can move between the
lower position above lower portion 17 to the raised position above
the inclined portion 16. The inclined portion 16 is curved in order
to provide a smooth transition of the trolley 30 to and from the
upper 18 and lower 17 portions.
[0052] Components of the drive system for the trolley are disposed
between the walls 11 of the base frame 10 and are illustrated in
FIG. 7. A chain 82 is positioned around a drive sprocket 45 and
guide pulleys 91, 94 and 96 and attached to the trolley 30 at
opposite ends. A first end of the chain 82 is attaches to the
trolley 31 by means of attachment member 34 bolted to the chain 82
and the trolley body 30 at an end opposite the seat 20. From this
first end, the chain extends around the sprocket 45 down to a
floating idler pulley 91 which is mounted on a lever 92 for pivotal
movement about an axis defined by a shaft 93 supported at each end
by a wall 11 of the base frame 10. This arrangement allows movement
of the idler pulley 91 in order to retain tension in the chain 82
as the trolley 30 moves along the track 50. The chain extends from
the idler 91 over a guide pulley 94 supported between the walls 11
by a shaft 95. The chain further extends from the guide pulley 94
around a third pulley 96 supported on a shaft 97 near the end of
the lower portion 17 opposite the inclined portion 16. This pulley
96 reverses the chain direction back toward the drive sprocket 45
for connection to a second trolley attachment member 33 at an end
of the trolley 30 nearest the seat 20. Similar to the first
attachment member, the second attachment member 33 is bolted to the
chain 82 and the trolley body 31. With the seat 20 in the lowered
position as shown in FIG. 1, rotation of the sprocket 45 in a
clockwise direction drives the chain 82 in a manner that pulls the
trolley 30 along the track 50 up the inclined portion 16 to the
upper portion 18, moving the seat 20 toward the upper position
shown in FIG. 2. The shafts 95 and 97 that support the pulleys 94
and 96 at the lower portion 17 further are connected to a wall 11
of the base frame 10 at either so that they not only support the
pulleys, but also keep the walls spaced apart at that end of the
apparatus.
[0053] The rotation of the drive sprocket 45 is achieved by means
of the control device 40. The control device 40 includes a drive
wheel 49 having a series of handles 41 formed by holes
circumferentially spaced around the wheel. As seen in FIGS. 3 and
4, the drive wheel is attached to a rotatable member 46 by means of
bolts 43. The rotatable member is fixed on the same shaft 45 as the
drive sprocket 81. The shaft 45 extends transversely through
aligned holes in the vertical walls 11 of the base frame 10 near
their upper edges 12 at the upper portion 18. The shaft is free to
rotate with respect to the frame 10, but lateral movement along its
axis is prevented by the combination of a pin 48 and blocking plate
47 as shown in FIGS. 3-6. The blocking plates 47 are supported on
the shaft 45 just outside each vertical wall 11 and the pins 48
pass through openings in the shaft just outside the plates. Lateral
movement of the shaft 45 with respect to the frame 10 is prevented
by the abutment of either pin 48 with the respective blocking plate
47. Rotation of the drive wheel 40 and attached rotatable member 46
causes the sprocket 81 to turn and drive the chain 82, resulting in
motion of the trolley 30 and attached seat 20. The wheel 40 is of
sufficient size that the handles 41 are within reaching distance of
the user when supported on the seat 20 regardless of the position
of the trolley 30 along the track 50. The amount force needed to
pull the seated user up the inclined portion 16 is kept reasonably
small as the relatively large radius of the driver wheel 49 ensures
a proportionally large resultant torque about the axis of the shaft
45.
[0054] The force of gravity on the user when seated in the raised
position tends to cause the trolley 30 and attached seat 20 to
descend down the inclined portion 16 to the lowered position. As a
result, a locking mechanism is provided for selectively securing
the trolley 30 in the track 50 at the upper portion 18 of the walls
11 of the base frame 10, thus locking the seat 20 in the raised
position above the inclined portion 16. A hole 42 in the driver
wheel 49 is positioned in order to align with a corresponding hole
14 in the wall 11 of the base frame 10 on the same side of the lift
apparatus 1 as the wheel 49 when the seat 20 is in the raised
position. A pin 70 is passed through the aligned holes 42 and 14 in
order to prevent motion of the wheel 49 with respect to the base
frame 10. Since the wheel 49 is attached to the rotatable member 46
which is mounted on the same shaft 45 as the drive sprocket,
rotation of any of these components is prevented by the pin 70. The
trolley 30 and seat 20 cannot move with the pin 70 in place as the
cogs of the stationary sprocket 81 prevent motion of the chain
82.
[0055] A pivoting mechanism 60 is provided between the trolley 30
and the seat 20 to allow pivotal motion of the seat with respect to
the trolley as they move along the track 50. A pair of hinges 63
provides the pivoting action between the seat 20 and trolley 30.
Each hinge has flaps 61 and 62 attached to the trolley body 31 and
the seat 20 respectively. As shown in FIG. 1, the hinge 63 allows
the bottom portion 22 of the seat 20 to take on a nearly horizontal
orientation in the lowered position at the lower portion 17 of the
wall 11 even though the trolley 30 is at an angled orientation
along the inclined portion 16. As the trolley 30 is pulled upward
along the inclined portion 16 by the chain 82 the hinge will open
further such that the bottom portion 22 of the seat 20 will take on
an the same orientation as the trolley 30, in other words parallel
to the inclined portion 16. An abutment member 64 is attached to
the underside of the bottom portion 22 of the seat 20 in order to
prevent the hinge 63 from opening more than 180 degrees. In the
raised position shown in FIGS. 2 and 7, the hinge 63 opens under
the weight of the seat 20 (and user, if seated thereupon) and moves
the abutment member 64 into contact with the trolley body 31. This
keeps the bottom portion 22 of the seat in a generally horizontal
orientation in which the user can easily get on or off the seat 20
for entering or exiting the tub respectively.
[0056] Due to the handles 41 circumferentially disposed about the
drive wheel 49 the lift is operable by either the bather or an
assistant. The bather is lowered into the tub from the raised
position shown in FIG. 2 by removing the locking pin 70 from the
aligned holes 42 and 14 in the drive wheel 49 and wall 11
respectively. The weight of the bather on the seat will tend to
move the seat 20 and attached trolley 30 down the inclined portion
16, pulling on the chain 82 and causing counter clockwise rotation
of the sprocket 81 and the attached shaft 45. Since the driver
wheel 49 is mounted on the same shaft 45 by means of the rotational
member 46, the counter clockwise rotation can be resisted by means
of the handles 41, thereby controlling the speed of descent of the
bather towards the lowered position shown in FIG. 1. In order to
exit the tub, the seat 20 is moved upward along the inclined
portion 16 from the lowered position by rotating the driver wheel
49 clockwise by means of the handles 41. Once the seat 20 has
reached the raised position, the holes 41 and 14 of the locking
mechanism will be realigned so that the locking pin 70 can be
inserted to lock the seat in the raised position while the bather
dismounts the lift apparatus.
[0057] The above description outlines a single embodiment of the
present invention from which a number of alternate embodiments can
be derived by those who are skilled in the art. Alternate styles of
frames, seats, trolleys, tracks, drive members, driven members and
guide members can be assembled to achieve similar results. One
alternate embodiment may employ a rope and winch for lifting and
lowering the seat, in which case the rope would only have to extend
between the winch and the end of the trolley nearest the upper
portion eliminating the need for the guide and tension pulleys.
Another alternate embodiment could use a notched belt and pulley
combination instead of the chain and sprocket. Other embodiments
could feature a trolley arranged to move along a single track
member or elongate handles extending outward from the drive wheel
transverse to the apparatus. The trolley and seat could also be
combined into a single rigid component, eliminating the need for
the pivoting mechanism. In this arrangement, the track would not
extend to a horizontal upper portion of the frame. The trolley
would only move along an inclined section of track and therefore
would always be oriented at the same angle with respect to the
frame. Without the pivot mechanism, the seat would not move
relative to the trolley but would remain fixed at an orientation
similar to that of the lowered position of the seat in the
preferred embodiment, as shown in FIG. 1. As a result, the bottom
portion of the seat would remain in a generally horizontal
orientation when moving between the lowered and raised
positions.
[0058] Since various modifications can be made in my invention as
herein above described, and many apparently widely different
embodiments of same made within the spirit and scope of the claims
without department from such spirit and scope, it is intended that
all matter contained in the accompanying specification shall be
interpreted as illustrative only and not in a limiting sense.
* * * * *