CA2557248A1 - Hydraulic bath lift - Google Patents

Abstract

A lift apparatus includes a hydraulic lift assembly and a mounting assembly for releasably securing the apparatus on upper edge portions of a bathtub. The lift assembly is operable to raise or lower a user seated on a lift chair into and/or out of the tub. The lift assembly includes a support cylinder secured to the mounting assembly and a hydraulically actuable cylinder piston which may be selectively raised or lowered by regulating the flow of water into or from the cylinder. The lift chair is selectively movable by way of the lift assembly piston between an undeployed loading position, where the chair is positioned over the exterior edge of the tub, and a deployed position where the chair is moved over the tub and lowered to partially immerse the user. The mounting assembly includes a generally flat base plate having a length and width configured for juxtaposed contact with the upper surface of the tub side, and which has a downwardly open square C-shape. At least one cantilevered support arm is provided towards the ends of the base plate. The support arm extends horizontally to one side of the base plate to a respective distalmost end which rests against the upper surface of the inner side edge of the bathtub. A series of clamping elements are provided at longitudinally spaced locations along the base plate. The hand clamps are configured to allow their tightening against the sides of the tub, to firmly affix the base plate together with the bath lift in position over the exterior side of the tub.

Description

HYDRAULIC BATH LIFT APPARATUS
SCOPE OF THE INVENTION

The present invention relates to a lift apparatus which uses household water pressure to selectively raise or lower a person into a bathtub, and more particularly a portable lift apparatus, which is adapted for installation on a standard bathtub without requiring the permanent installation of customized mounting plates which otherwise might damage the tub or surrounding tiled floor or tile areas.

BACKGROUND OF THE INVENTION

Bath lift apparatus for raising or lowering individuals into a bathtub are well known.
Typically, conventional lift apparatus such as that described in United States Patent No.
3,815,163 to Sullivan are provided with a lift chair on which a user sits. The lift chair in turn is vertically and horizontally movable in a cantilevered arrangement on a support post. Typically, the chair is moved by water pressure in 180 of lateral movement between an initial undeployed position, where the chair is positioned on or over the bathroom floor adjacent the bathtub, and a deployed position where the chair is moved over and lowered into the tub to allow bathing.

Conventional lift apparatus suffer a disadvantage in that because the chair is cantilevered from the post, through 180 of movement, it is typically necessary that the support pole be permanently affixed by mounting plates screwed into the floor and ceiling of the bathroom to provide the necessary stability. The permanent affixation of the lift apparatus in bathroom environments, in addition to making portability impractical, frequently results in damage to the surrounding tile walls and floors, necessitating that substantial repairs be made following the removal of the apparatus.

In addition, the necessity of permanently installing the apparatus in homes, frequently necessitates the hiring of plumbers, carpenters and/or other tradesmen, increasing the overall cost of the device.

SUMMARY OF THE INVENTION

To at least partially overcome some of the difficulties associated with prior art devices, the present invention provides to a hydraulic lift apparatus for use in raising and lowering an individual into a bathtub, and which includes a hydraulic lift assembly which is coupled to a mounting plate configured for securement along a top edge of the side of a tub by a series of releasable clamping members. The clamping members further permit the simplified removal of the apparatus for use elsewhere.

Another object of the invention is to provide a hydraulically operable bath lift apparatus, which utilizes household water pressure to activate a lift piston used to selectively raise or lower an individual into a bathtub, and which may be stably secured in place without the requirement of inserting screws, bolts or other permanent fasteners to the tub or its surrounding wall or floor areas which otherwise may damage tile floors and/or the tub enclosure.

Another object of the invention is to provide a portable bath lift apparatus which may be inexpensively manufactured and which is adapted for simplified installation while conforming with safety standards.

Another object of the invention is to provide a bath lift apparatus which is re-usable, whereby the hydraulic lift and the stabilizing platform are simply disconnected, and easily transported for installation at a new location. Optionally, the invention may provide for stabilizing platform dimensions which may be modified to adapt to a new size tub.

The present invention provides a lift apparatus which includes a mounting assembly for stably and releasably supporting the apparatus on upper edge portions of a conventional bathtub.

A hydraulically operable lift assembly is assembled on the mounting assembly and used to raise or lower a user seated on a lift chair into and/or out of the tub. The lift assembly includes a support cylinder secured to the mounting assembly and a hydraulically actuable lift cylinder.
The lift cylinder is selectively raised or lowered by regulating the flow of water from a water supply, and most preferably from the tub faucet or a dedicated household water supply line, into and out of the cylinder.

The lift chair is selectively movable by way of the lift cylinder between an undeployed loading position, where the chair is moved to a position to enable the user to be seated comfortably thereon, and a deployed position where the chair is moved over the tub and lowered to partially immerse the user. Most preferably, the chair is moved by the lift cylinder both vertically a height of at least 35 cm and more preferably between 54 and 76 cm, as well as horizontally through an arc approximately 60 to 120 of movement, and more preferably about 90 of movement. In a most preferred construction, in the loading position, the lift chair is positioned so as to align the weight of a user seated thereon, substantially directly over the upper surface of the exterior side edge of the tub.

The mounting assembly includes a generally flat base plate having a length and width configured for juxtaposed contact with the tub side edge. Although not essential, the support cylinder is preferably positioned in a mid portion of the base plate to evenly distribute load forces of the lift assembly and chair thereon. The base plate is preferably formed having a downwardly open square C-shape. The base plate includes a medial portion having a width selected to enable its placement seated over the exterior edge of the tub, and a length chosen at between about 1.2 and 2 metres. Optionally, the base plate may be formed having a telescoping construction, allowing the plate to be lengthened or shortened having regard to the overall length of the exterior side of the tub with which the bath lift is to be used.

At least one and preferably a pair of cantilevered stabilizing or support arms are provided towards the ends of the base plate. The support arms extend horizontally along one side of the base plate towards the opposing inner tub side, to a respective distalmost end. The support arms have a length selected to rest against or otherwise engage either the upper surface of the inner side edge of the bathtub and/or alternately, the upper surfaces of the tub ends. Optionally, the support arms could be formed with a telescoping construction allowing adjustability in the final position of the distal ends.

A series of clamping elements, such as hand or spring clamps, are provided at longitudinally spaced locations along the base plate. The hand clamps are configured to allow their tightening against the sides of the tub, to firmly affix the base plate together with the bath lift in position over the exterior side of the tub, retaining the base plate thereon in a friction-fit arrangement.

The applicant has appreciated that in the most preferred construction, because the chair only moves between the loading position where the user's weight is substantially aligned over the base plate and exterior tub edge, and the inboard deployed position, the combination of the hand clamps and the cantilevered support arms ensure that the lift apparatus is maintained in a stable and safe position, without requiring screws or other such permanent installation of the lift apparatus. In addition, the cantilevered arrangement of the support arms enables the lift assembly to be manufactured more compactly and economically.

Accordingly, in one aspect the present invention resides in a portable seat lift for a bathtub comprising:

a longitudinally elongated base for mounting on a first side edge of the bathtub, a lift cylinder secured at its lower end to said base, said cylinder being provided with a piston movably upwardly relative to said cylinder, said piston being moveable between retracted positions and extended positions;

a seat coupled to said cylinder for supporting a person in a seated position thereon, means for directing water from the faucet of said tub into said cylinder for applying hydraulic pressure for extending of said piston, said means including a valve having an inlet and an outlet and selectively moveable between a first position in which the water passes from said faucet into said cylinder to extend said piston and a second position for releasing said water from said cylinder through said outlet.

In a preferred aspect, the seat lift is provided with one or more safety devices to ensure its proper operation. In a most preferred construction, the seat lift includes a water shut-off rod or lever to arrest lifting movement beyond a predetermined safe limit. The shut-off rod or lever may be connected to a piston which is operable to actuate a valve stem lever to stop the flow of hydraulic lift fluids when the seat achieves a predetermined height position.
As well, a check valve may be provided in a water supply line to maintain the lift cylinder in position if, for example, water pressure fails.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference may now be had to the following detailed description taken together with the accompanying drawings in which:

Figure 1 shows schematically a top view of a hydraulic bath lift apparatus in accordance with a preferred embodiment, installed for use on a bathtub;

Figure 2 illustrates a partial cross-sectional side view of the bath lift of Figure 1 with the seat in a partially deployed position, moved over the bathtub interior;

Figure 3 illustrates a partial top view of the lift cylinder used in the apparatus of Figure 1, illustrating the movement of a seat between deployed and undeployed positions;
and Figure 4 illustrates a bath lift in accordance with an alternate embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference is first made to Figure 1 which shows a bath lift 10 in accordance with a preferred embodiment of the invention, installed for use with a conventional bathtub 12. As will be described, the bath lift 10 includes a lift chair 14 used to selectively raise or lower an individual (not shown) into the tub interior 16, a lift assembly 18 used to selectively actuate movement of the lift chair 14, and a mounting assembly 20 used to secure the bath lift 10 in position relative to the tub 12 in use.

Figures 2 and 3 show best the lift chair 14 as preferably formed from molded plastic or other corrosive resistant material, and including a horizontal seating portion 22 and a back support 24. The chair 14 may be of any of a variety of suitable shapes or designs selected to stably support a user suspended in horizontal and vertical movement thereon.
Although not shown, the chair 14 could also optionally be provided with arm rests which are either integrally or removably attached to the seating portion 22 and/or back 24.

As shown best in Figure 2, the lift chair 14 is secured to the lift assembly 18 by means of a Z-shaped seat hangar bracket 26, and which is, in turn, secured to the mounting assembly 20.
The hangar bracket 26 is similarly fabricated from corrosive resistant material, such as plated metals, stainless steel, or more preferably polymeric materials. The bracket 26 is used to translate movement of the lift assembly 18 to the chair 14 in operation of the lift 10. As shown best in Figure 1, the lift chair 14 is movable by the lift assembly 18 between a loading position, shown best in phantom in Figure 3, and the deployed position shown in solid lines, where the lift chair 14 is moved over and downward into the tub interior 16. In the loading position, the chair 14 preferably orients so that the seating portion 22 is positioned so as to be centered directly over the upper surface of the exterior side 28a of the bathtub 12, and with the chair back support 24 oriented inwardly towards the opposing interior tub side 28b. In this position, the user may simply sit backwards onto the chair 14, ready for use of the lift 10. As the chair 14 is swung to the deployed position, the back support 24 pivots to move proximate to the rear end 29a of the tub 12, so that the user faces the forward end 29b.

Although not shown, the chair 14 may optionally be provided with leg supports to maintain the user's legs in a raised position as the lift chair 14 is moved between the undeployed and deployed positions.

Figures 2 and 3 illustrate best schematically the lift assembly 18 as including a support cylinder 30, and a hydraulically operable lift piston 32. The lift piston 32 and cylinder 30 are preferably formed of corrosive resistant materials and may, for example, be formed of metals such as stainless steel, aluminum or most preferably engineering polymers, such as DelrinTM sold by DuPont. The cylinder 30 and piston 32 are formed with sufficient strength and structural integrity so as to resist deformation and bending under load forces of at least 100 kg, and more preferably 150 kg.

One or more plastic bushings or annular rings 42 may be positioned within the top and bottom of the cylinder 30 interior to assist in maintaining fluid seals, and support and guide the vertical sliding movement of the piston 32 relative to the cylinder 30. As shown best in Figure 3, in a most simplified construction, the upper end 43 of the seat hangar bracket 26 is secured to an upper end portion of the piston 32 for movement therewith. Optionally, a radially extending fender 45 made of engineering polymers, or other suitable materials with adequate surface friction, and mechanical properties, such as suitable plastics or TeflonTM is secured to an outer side of the cylinder 30. The fender 45 projects outwardly from the cylinder 30 and is provided to maintain the bracket 26 a spaced distance from the tub side 28a as the seat 14 is raised and lowered. A pair of rotation stops 40a,40b are further positioned on the outside of the cylinders.
The stops 40a,40b are configured to engage edge portions of the connecting bracket 26 to limit its horizontal rotational movement about the cylinder 30.

The piston 32 is movable vertically relative to the support cylinder 30 within an operating range of a height h (Figure 2) selected at between about 60 and 90 cm by hydraulic pressure provided through the selective supply of water into or from the lower end of the cylinder 30.
Water is supplied into the cylinder via conduit tubing 31. The tubing 31 is provided in fluid communication with either the bathtub faucet through a temporary connection hose, or alternately through a dedicated water supply line connected directly to the household water supply. A control pane134 and check valve 35 are provided to regulate water flow along the tubing 31 and to and from the cylinder 30. Preferably, the control panel 34 and manual pump 37 are further provided to regulate water supply and hydraulic pressure. In the event of a supply pressure failure arising from either a general shutoff by the municipality, or from an inlet line failure, the check valve 35 would close and retain the water in the cylinder 30. This assures that the seat 34 would not fall, and the user would be protected. In the event of a pressure failure while the user is in the tub 12, the pump 37 may be used to move water from the tub 12 into the cylinder 30 to raise the connecting hangar 26 of seat 14 to exit level, avoiding trapping someone in the tub 12. Most preferably, the control pane134 is positioned at a 45 angle relative to the longitudinal extent of the exterior side 28a of the tub 12, and facing towards the lift chair 14 and user. The control pane134 may, for example, be used to activate a solenoid or ball valves to effect water flow into the cylinder 30 to raise or lower the piston 32. If desired, cylinder 30 may furthermore be provided with one or more overflow ports 41 to provide fluid pressure release, so as to limit upward movement of the piston 32 beyond a desired maximum height.

The horizontal rotation of the seat 14 relative to the tub side 28a may be effected in a number of possible ways. In a simplified construction, the entire lift assembly 18 is rotatably mounted to mounting assembly 20, enabling the rotational movement of both the cylinder 30 and piston 32 as a single unit.

Alternatively, the lift assembly 18 may be fixedly secured against rotational movement, and the seat hangar bracket 26 rotatably connected to the top of the piston 32 for movement thereabout.

In a still alternate construction, the piston 32 may be selectively rotatable relative to the cylinder 30 either manually or automatically. In one such possible embodiment, the cylinder 30 may be provided with a number of helical grooves spaced towards its upper end, with the piston 32 having flutes, and which are configured for complementary engagement with the grooves.
The engagement of the flutes within the helical grooves as the piston 32 is raised and lowered effects the rotation of the piston 32 relative to the cylinder 30 to move the hangar bracket 26 and lift chair 14 between the undeployed and deployed positions shown in Figure 2.

The rotation stops 40a,40b are preferably provided to limit rotational movement of the piston 32 and lift chair 14 past the desired positions, and most preferably, the piston 32 and lift chair 14 are limited in horizontal rotational movement along an arc of movement between about 0 and 180 , and most preferably about 90 .

Figures 1 and 2 show best the mounting assembly 20 used in securing the bath lift 10 in place on the tub 12. The mounting assembly 20 includes a longitudinally elongated base plate 42, a pair of cantilevered positioned support beams 44a,44b and a number of clamping brackets 46a,46b. The base plate 42 may be formed as a generally flat panel or alternately provided as a generally square C-shaped construction. The plate 42 is preferably formed of stainless steel and includes a generally planar medial section 48 and where a C-shaped profile is used, includes two downwardly extending flange portions 50a,50b which extend perpendicularly along each longitudinal edge of the medial section 48. Figure 2 shows best a preferred construction wherein the cylinder 30 as being secured at its lower end to a medial portion of the base plate 42.
Although the preferred embodiment describes the base plate 42 as being formed of stainless steel, the invention is not so limited. Other materials may also be used including aluminum or, if desired, enamelized metal or polymeric materials.

The medial portion of base plate 42 is formed having a lateral width of preferably between about 12 and 24 cm, enabling it to be placed in juxtaposed contact with the upper surface of the exterior side 28a of most conventional bathtubs. The base plate 42 preferably has a longitudinal length selected at between about 1.5 and 2 metres so as to provide adequate stability to the bath lift 10 in the deployment of the lift chair 14. If desired, the base plate 42 could be adjustable in length, as for example by telescoping in its longitudinal direction, to allow more fitted placement depending on the longitudinal length of the bath installation. Optionally, rubber or plastic pads or padding 49 (Figure 2) may be provided along the lower surface of the medial portion 42 to protect the tub from marring or scratching.

As shown best in Figure 1, the support beams 44a,44b extend parallel to each other and horizontally towards the interior tub side 28b from locations at each longitudinal end of the base plate 42. The support beams 44a,44b preferably have a longitudinal length of between about .6 and 1 metres, so as to extend from the base plate 42 to a respective distal end aligned over the upper surface of the interior tub side 28b. A rubber or silicone friction pad 60 is positioned at the distalmost end of each support beam 44a,44b for providing a mar-free friction contact with the interior side 28b of the tub 12. Optionally, the support beams 44a,44b may also be telescoping in length to allow adjustment in the final positioning of the pads 60, depending upon the tub width and actual site of installation. It is to be appreciated that the engagement of the friction pads 50 of each support beam 44a,44b with the upper surface of the side 28b provides the necessary lateral support to the bath lift 10 maintaining it in the correct position as the lift chair 14 is moved to a cantilevered deployed position into the tub interior 16.

The clamping brackets 46a,46b are shown as being provided at longitudinally spaced positions along the base plate 42 and extend vertically down the sides of the tub 12 to prevent movement of the plate 42. In a simplified construction, each of the clamping brackets 46a,46b are provided as threaded hand screws which extend through internally threaded apertures. The selective tightening of the hand screws enables movement of non-marring silicone pads into bearing contact against the exterior side 28a of the tub 12. The use of the clamping brackets 46a,46b advantageously ensures the fixed positioning of the bath apparatus 10 in place over the bathtub 12, while enabling simplified removal of the apparatus 10 for use elsewhere.

It is appreciated that because the lift chair 14 does not move outwardly past the undeployed position aligned over the exterior side 28a of the tub 12, there is no requirement to support the apparatus outside the tub enclosure. As a result, the bath lift 10 may be easily installed without requiring the insertion of permanent fasteners through tile floors or walls. It is, however, envisioned that although less desirable, the use of such fasteners could be provided where permanent installation of the bath lift 10 is of interest.

Reference may be had to Figure 6 which illustrates an alternate embodiment of the bath lift 10 wherein like reference numerals are used to identify like components.
In Figure 6, the lift assembly 18 is provided with a comparatively elongated cylinder 30. The cylinder 30 has a height selected so that the mounting assembly 20 is secured to the tub edge 28, the upper end portion of the cylinder 30 locates so as to engage a socket-like bracket 70 secured to the bathroom ceiling 72.

In the embodiment shown, the cylinder 30 is secured to the plate 42 at its lower end by means of a swivel pin 76. The upper bracket 70 furthermore includes a rotatable bushing 78 enabling the cylinder 30 and piston 32 to rotate as a single unit on top of the tub side 28a to move the chair 14 between deployed and undeployed positions. The engagement of the upper end of the cylinder 30 within the bracket 72 provides further enhanced stability to the bath lift 10 in more permanent installation.

As shown in the exploded view, the lift piston 32 is movable within the interior of the cylinder 30 over a preferred vertical length selected at between about 30 and 50 cm, and more preferably about 40 cm. A longitudinally extending vertical slot 80 is formed through the sidewall of the cylinder 30 to enable substantially unhindered movement of the seat hangar bracket 26 vertically with the piston movement 32.

Although the detailed disclosure describes and illustrates various preferred embodiments, the invention is not so limited. Many modifications and variations will now occur to a person skilled in the art. For a definition of the invention, reference may be had to the appended claims.

Claims (3)

1. A portable seat lift for a bathtub comprising:

a longitudinally elongated base for mounting on a first side edge of the bathtub, a lift cylinder secured at its lower end to said base, said cylinder being provided with a piston movably upwardly relative to said cylinder, said piston being moveable between retracted positions and extended positions;

a seat coupled to said cylinder for supporting a person in a seated position thereon, means for directing water from the faucet of said tub into said cylinder for applying hydraulic pressure for extending of said piston, said means including a valve having an inlet and an outlet and selectively moveable between a first position in which the water passes from said faucet into said cylinder to extend said piston and a second position for releasing said water from said cylinder through said outlet.

2. A portable seat lift as claimed in claim 1 further including at least one laterally extending support arm coupled to said base, said support arm extending to a distal end portion positioned for engagement with a second other edge of said bathtub.

3. A portable seat lift as claimed in claim 1 wherein said first side edge comprises an exterior side edge and said second other edge comprises an inner tub side edge.