CA2174787A1 - Portable movable seat - Google Patents
Portable movable seatInfo
- Publication number
- CA2174787A1 CA2174787A1 CA002174787A CA2174787A CA2174787A1 CA 2174787 A1 CA2174787 A1 CA 2174787A1 CA 002174787 A CA002174787 A CA 002174787A CA 2174787 A CA2174787 A CA 2174787A CA 2174787 A1 CA2174787 A1 CA 2174787A1
- Authority
- CA
- Canada
- Prior art keywords
- seat
- plate
- assembly
- seat assembly
- base plate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61G—TRANSPORT, PERSONAL CONVEYANCES, OR ACCOMMODATION SPECIALLY ADAPTED FOR PATIENTS OR DISABLED PERSONS; OPERATING TABLES OR CHAIRS; CHAIRS FOR DENTISTRY; FUNERAL DEVICES
- A61G5/00—Chairs or personal conveyances specially adapted for patients or disabled persons, e.g. wheelchairs
- A61G5/10—Parts, details or accessories
- A61G5/14—Standing-up or sitting-down aids
-
- A—HUMAN NECESSITIES
- A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
- A47C—CHAIRS; SOFAS; BEDS
- A47C3/00—Chairs characterised by structural features; Chairs or stools with rotatable or vertically-adjustable seats
- A47C3/18—Chairs or stools with rotatable seat
Landscapes
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Seats For Vehicles (AREA)
Abstract
A portable seat assembly for invalids, handicapped and elderly persons is designed to be placed and secured on a support surface of a chair structure, such as the passenger side seat of an automobile. The seat assembly has a seat plate with a cushion pad for receiving a user, a base plate for engaging the automobile seat, and a swivel plate intermediate the base plate and the seat plate. A support assembly is provided for supporting the seat plate on the swivel plate and the swivel plate on the base plate. The support assembly has a twist support component for providing at least limited rotational movement of the swivel plate relative to the base plate, and a slide support component for providing limited fore and aft sliding movement of the seat plate relative to the swivel plate either separately or concurrently with the rotational movement. A locking mechanism selectively locks the rotational and sliding movements in a plurality of positions.
Description
TEM File No. 109.1 TITLE: PORTABLE MOVABLE SEAT
FTFT n OF T~F TNVFNTION
The present invention relates to a portable movable seat assembly, and in particular to a seat assembly to assist disabled persons in the ingress and egress of chair structures 10 which are difficult to access, such as the passenger side seat of automobiles and the like.
RAcKGRouNn OF THF TNVENTION
As populations increase and age, there is a growing need for devices to help disabled persons, ranging from those with arthritis to paraplegics, to be able to access 15 (namely to sit down on and to stand up from) chair structures of various types and in various locations, ranging from a sofa in one own's home to automobile seats. Some chair structures are also becoming increasingly difficult to reach, a prime example of which is the automobile seat. Modern automobiles are generally small, compact and low to the ground, making it difficult for someone who is not very mobile to enter and exit such 20 automobiles.
Some of these problems have been addressed by the many me~ ed devices for making automobiles wheel-chair accessible, such as ramp like devices for lifting persons into the automobile. However, these devices are generally very bulky and often may only be used with larger vehicles such as vans Such devices are usually very expensive as well, 25 not counting the cost of having to specially purchase a large vehicle to accommodate the device. Once mounted, the ramp devices are not transferable for use elsewhere, such as in a home.
Less expensive and portable seating aids are known, but have seen limited use due to several disadvantages One example is the seat in US patent 3,185,523 (Morrill) where 30 a top pad is free to slide and rotate on a bottom pad This seat is rather dangerous since it lacks any mech~ni.cm for controlling or limiting such movement other than a single fiexible strap connected between the two pads.
21 147~7 Another example is the movable seat in US patent 3,043,622 (Milner). Although a bottom plate has a guide track for the top seat pad, the track lirnits the seat pad to a single type of arcing movement, for example the seat pad can not slide forward without having to rotate as well. In addition, it does not have a means of conveniently locking the seat 5 pad in one position on the track.
An improvement over these prior devices is found in C~n~ n patent 1,312,814 (Switzer) which shows a supporting mech~ni~m for a seat component on a base component. Although the supporting mech~ni~m allows for both rotational and sliding movement of the seat on the base, it also lacks certain desirable features. The seat can only 10 be locked in one position, namely only when the seat is fully retracted and facing forward.
Hence movement of the seat can not be locked when the seat is extended or rotated. The locking latch is inconvenient or difficult to reach since it is located behind the user, nor does it have a biaser or equivalent assembly for a positive lock. The supportingme~h~ni~m also raises the seat rather high off the base due to the ball race bearing 15 meçh~ni~m and rail assembly used at the time.
What is desired therefore is a portable seat assembly which overcomes the limitations and disadvantages of these other prior devices. Preferably the device should provide for concurrent or separate rotational and sliding movement of a seat on a base.
Such motion should be positively locked in numerous di~erenl positions. A manual20 controller should be provided so that a user may easily and conveniently control locking and unlocking of such movement. The device should be easy to transport and install in automobiles or the like, and not interfere with use of an automobile's other safety features, such as seat safety straps. The device should further have a support assembly which overcomes the height disadvantages of the prior devices, is relatively light weight, and 25 which reduces or elimin~tes the need for ball bearings.
SUMMARY OF THE INVENTION
According to the present invention there is provided a portable seat assembly for placement on a support surface of a chair structure comprising:
a seat plate;
a base plate for eng~ging said support surface;
a swivel plate intermediate said base plate and seat plate;
a support assembly for supporting the seat plate on the swivel plate and the swivel plate on the base plate, said support assembly having a twist support component for providing at least limited rotational movement of the swivel plate relative to the base plate, and a slide support component for providing limited fore and aft sliding movement of the 5 seat plate relative to the swivel plate either separately or concurrently with said rotational movement; and a locking mech~n;~m for selectively locking said rotational and sliding movements in a plurality of positions.
10 DFSC~rPTION OF THE DRAWINGS
Embodiments of the invention will now be described, by way of example onlyj withreference to the accompallyil1g drawings, wherein:
Figure 1 is a perspective view of a portable seat assembly mounted on a support surface of a chair structure, namely an automobile's passenger seat, according to a 15 prerelled embodiment ofthe present invention;
Figures 2a, 2b, 2c and 2d are plan views of the seat assembly of fig. 1 showing,respectively, a seat plate of the seat assembly in a fully retracted position, a fully extended position, rotated about 90 degrees clockwise in the fully extended position, and rotated about 90 degrees clockwise in the fully retracted position.
Figure 3 is a plan view of the seat assembly in fig. 1 showing the seat plate in a fully retracted position on a swivel plate and, in phantom outline, a slide support component of a support assembly, and a slide lock component and a portion of a twist lock component of a locking meçll~ni~m;
Figure 4 is an elevated side view of the seat assembly of fig.3;
Figure 5 is an elevated frontal view of the seat assembly taken along line 5-5 of fig.3;
Figure 6 is a partial cross-sectional view taken along line 6-6 of fig.3 showing a portion of the slide lock and twist lock components;
Figure 7 is a partial elevated side view taken along line 7-7 of fig.3 showing a30 portion of a m~nll~lly operable controller;
Figure 8 shows the seat assembly of fig.3 in a fully extended position;
Figure 9 is a plan view of the seat assembly in fig.1 with the seat plate removed, and showing in phantom outline a portion of a twist support component of the support assembly;
Figure 10 is an exploded view of the twist support component of the seat assembly 5 of fig.1, showing a portion of a twist lock component of the locking meçh~ni.~m;
Figure 11 is a plan view of the twist support component of fig.10;
Figure 12 is a side view of the twist support component of fig.11;
Figure 13 is a cross-sectional view along line 13-13 of fig.11; and Figure 14 is a plan view of a portion of the twist support component of fig.11 10 shown mounted on the base plate ofthe seat assembly ofthe present invention.
nF.SCRTPTION OF PRF.FFRRF.r~ F.MBOn~l~FNT
Reference is first made to fig.1 which shows a p.erel-ed embodiment of a portable seat assembly or device (indicated generally by reference numeral 20) placed on a support 15 surface 22 of a chair structure 24. Details of the device are omitted in this view, such as a m~n~l~lly operable lever 36 to be described later The chair structure 24 shown in fig.1 is the passenger side seat in a vehicle or passenger automobile having a back rest 26 and a head rest 27. The support surface 22 will therefore be referred to sometimes as a vehicle seat or seat rest. As shown, the seat device 20 is adapted for use on the automobile seat 20 24 by inclusion of one or more securing belts 28 as will be described later. However, it will be appreciated that the seat device 20 may be used, with slight modifications if needed, on support surfaces other than in vehicles, such as on chairs in residences, nursing homes or hospitals for example.
The seat device is designed to help a disabled or physically handicapped person to 2~ get into and out of a chair, such as the vehicle seat 24. Figures 2a-2d, which show the seat device 20 in plan view on the vehicle seat 24, illustrate the general movement and operation of the seat device. Details of the seat operation are set out later. Referring to fig.2a, a seat plate 30, having a removable padded upper support surface or cushion pad 32 shaped to receive a user, is shown locked in a fully retracted position and facing 30 forward (as indicated by directional arrow 34). A m~ml~lly operable controller or lever 36 is used to unlock the seat device 20, as described later, to allow the seat plate 30 to slide forward on a swivel plate 38 to a fully extended position shown in fig.2b, where sliding of 2~ 74787 the seat plate 30 may be locked if desired. Either separately or concurrently with the sliding motion, the seat plate 30 and the swivel plate 38 may be rotated about 90 degrees clockwise relative to a base plate 40 and the vehicle seat rest 22 to the position shown in fig.2c. The lever 36 is used to selectively lock the rotation of the swivel plate 38 relative 5 to the base plate 40 in the forward facing position (figs.2a and 2b), in the 90 degree rotated position (fig.2c), or in a plurality of rotated positions therebetween, as desired.
Figure 2d shows the seat plate 30 slid back on the swivel plate 38 to a fully retracted position. The fig. 2c and 2d positions will typically be used to help a user enter or exit the vehicle and the vehicle seat 24, and the fig.2a and 2b positions will typically be used help a 10 user get properly adjusted to a sitting position on the vehicle seat 24.
Details of the structure and mech~ni~m of the seat device 20 will now be described. Referring to figs.3, 4 and 5, the seat plate 30 is shown in the fully retracted position on the swivel plate 38 located intermediate the seat plate 30 and the base plate 40 which engages the vehicle seat rest 22. A support assembly for supporting the seat plate 15 30 on the swivel plate 38 and the swivel plate 38 on the base plate has two components:
(i) a slide support component (generally indicated by 42) for providing fore and aft sliding movement of the seat plate 30 on the swivel plate 38; and (ii) a twist support component 44 for providing rotational movement of the swivel plate 38 on the stationary base plate 40. The sliding movement may occur separately or concurrently with the rotational 20 movement, and visa versa, as explained below.
The slide support component 42 has a roller assembly 46 secured underneath the seat plate 30 and a guide assembly 47 secured on top of the swivel plate 38 to guide the sliding movement of the roller assembly 46. The roller assembly 46 has pairs of rollers 48 connected to generally vertical flanges 50 extending downwardly from opposite 25 longi~l~lin~l edges of the seat plate 30. The axles of each pair of rollers 48 are off-set to f~cilit~te mounting of the rollers on the flange 50. Also, the rollers 48 are located on opposite sides of the flange 50 to reduce stress concentrations in the vicinity of the roller/flange connection due to bending or twisting of the flange when weight is applied to the seat plate 30. Two pairs of rollers 48 are provided along each flange 50, one pair 30 toward the back of the seat plate 30 and the other pair in an area intermediate the front and back ends of the seat plate 30. More rollers could be used, but this is not prerelled due to increased weight of the seat device 20 and increased costs. It will be appreciated 2i 74787 that the fianges 50 may be substituted with individual brackets attached to the seat plate 30 for each pair of rollers 48, although this is also not plerelled due to the loss of the ing effect of the flanges on the seat plate 30.
The guide assembly 47 has a pair of parallel rails extending along opposite 5 longit~ n~l edges of the swivel plate 38 for receiving the rollers 48. Each rail is constructed of an inner L-shaped channel piece 52 and an outer Z-shaped channel piece 54. The rails formed by channel pieces 52, 54 confine the rollers 48 from side-to-side motion and from lifting off the swivel plate 38. At least one of the Z-shaped channel pieces 54 has a stop means to prevent escape of the rollers 48 from the rails in the form of 10 a set screw 56 at the front and an upwardly extending lip 58 at the rear of the Z-shaped channel piece.
The twist support component 44 of the support assembly, shown in figs.5 and 9 to14, uses a bearing-less (i.e. no ball bearings) assembly for rotating the swivel plate 38 on the base plate 40. The twist support component has a circular inner disk element 60 15 located within an outer ring element 62, said elements 60, 62 being rotatable relative to each other about a common axis of rotation 64. An opening 66, coincitling with the axis 64, receives a retainer bolt (not shown) which extends from the base plate 40 to the swivel plate 38 to retain the swivel plate on the base plate, thereby sandwiching the disk 60 therebetween. Good results have been achieved using a 5/16 inch elevator bolt with a 1 20 inch head countersunk into the durable plastic material of base plate 40 and capped with a lock nut (not shown) above the swivel plate 38. The disk 60 is fixed to the underside of the swivel plate 38 with a number of countersunk rivets (location indicated at 67), and the ring 62 is fixed to the top surface of the base plate 40 by a number of spaced rivets 68. To reduce frictional resistance between the metallic disk 60 and the plastic material of the 25 base plate 40, a pad of slide enhancing material 70 is located between the disk and the base plate. In the pr~relled embodiment, the pad 70 is of a size and shape comparable to the disk 60, and is made of a TEFLON material. The combined thickness of the disk 60 and the pad 70 should be greater than the thickness of the ring 62 to reduce or elimin~te any contact between the swivel plate 38 and the ring 62.
The twist support component 44 includes a stop means to limit the rotation of the swivel plate 38 relative to the base plate 40. The outer periphery of the disk 60 has a circumferential slot 72, and a limit pin 74 fixed to the base plate 40 protrudes through an aperture 71 in the pad 70 into the slot 72. Rotation of the swivel plate 38 is stopped when the pin 74 abuts or contacts an end of the slot 72 (as shown in fig.11, for example). In the pr~elled embodiment it is desired to limit the rotational movement to about 90 degrees, and so the slot 72 extends just over a quarter circumference of the disk 60 as shown.
S Referring specifically to fig.9, and to figs. 3, 5 and 8, a pair of oblong rollers 76 are provided at the front end of the swivel plate 38 and are adapted to run along the top surface of the base plate 40. The oblong rollers 76 enhance the above discussed rotational movement by limiting the deflection of the front end of the swivel plate 38 toward the base plate 40 when a user is seated on the seat device 20. Each roller 76 is supported on an 10 axle 78 fixed at its ends to the underside of the swivel plate 38. An opening 80 in the swivel plate 38 above each roller 76 avoids interference between the roller and plate 38.
The axles 78 are angled so that the rollers 76 follow a circular arc corresponding to the swivel plate's rotational movement. The rollers are preferably oblong to provide a relatively large roller in a vertically confined area. Two spaced rollers are used (as shown 15 in the figures) to provide stability to the swivel plate (i.e. to prevent the front of the swivel plate from rocking side to side during use).
The seat device 20 has a locking mech~ni~m for selectively locking the above mentioned rotational and sliding movements in a number of positions. Referring first to figs.3 and 5-8, the locking mech~ni~m has a slide lock component, generally indicated by 20 82, for locking the sliding movement of the seat plate 30 when the seat plate is fully n~led and fully retracted on the slide support component 42. The platform 30 is "fully"
retracted (fig.3) and "fully" extended (fig.8) when a movable pin 84 engages a front keeper or aperture 86, or a rear keeper 88, respectively, in the vertical leg of an L-shaped slide lock plate 85 ~tt~ched to the underside of the seat plate 30 and oriented parallel to 25 the roller guide channel 52. The "fully" retracted and extended positions are reached just before the rollers 48 would make contact with the sliding stop means, namely the set screw 56 and lip 58, respectively. The pin 84 is slidingly supported in an inverted C-shaped plate 90 with a spring 92 or equivalent biaser for urging the pin 84 toward the plate 85 and a locked position. Such a "fail safe" assembly ensures that the pin 84 will not 30 inadvertently ~i~eng~ge the keepers 86, 88. It will be appreciated that, if desired, more slide stop positions may be provided by adding further keepers on the slide lock plate 85.
The slide lock mech~ni~m 82 is controlled by the m~ml~lly operable lever 36 pivotally attached to the swivel plate 38 (best seen in figs.8 and 9) and an elongate coupler assembly 96 for operatively connecting the lever 36 to the locking mech~ni~m The lever has a first operative position generally parallel to the swivel plate (see fig.7) for locking S both the rotational and sliding movements of the seat device 20, and a second operative where the lever forms an acute angle with the swivel plate 38 (see fig.4) for unlocking both the rotational and sliding movements. In the pr~ ed embodiment, the lever is located at the left side of the seat device (i.e. to the left of a user when seated) and the acute angle is about 45 degrees for comfortable operation by a user when entering and 10 exiting the passenger side vehicle seat 24. The lever may be located elsewhere on the seat device 20 or a di~rerellt lever angle may be provided if need be. In addition, a cap 98 with detent system 99 (figs.3 and 7) provided at the base of the lever 36 allows a user to "feel"
when the lever has reached the first and second operative positions. A spring 100 keeps a required compressive force on the detent system 99.
The coupler assembly 96 has a flexible elongate hose 102 connected at one end to the lever 36 through a first brass fitting 104. The brass fitting 104 is serrated and the hose 102 is force fitted thereon. The other end of the hose 102 is also force fitted onto a second brass fitting 106 which is secured to an elongate rod 108 rotatably carried by a C-shaped plate 110 on the swivel plate 38 (see figs. 3, 5, 6 and 10). The front end of the rod 20 108 has a collar with a cam 112 fixed thereon. One end of a throw rod 114 is attached to the cam 112 and the other end is attached to the sliding lock pin 84. Hence movement of the lever 36 is transferred to the pin 84 by a twisting motion through the hose 102 and rod 108, and is then tran~l~ted to a linear or sliding motion by the cam 112 to the throw rod 114. For example, upward movement of the lever 36 to the second operative position or 25 unlocked position results in a pulling/tension force on the throw rod 114 which pulls the lock pin 84 away from the keepers 86, 88 in the slide lock plate 85 to allow sliding motion of the seat plate 30. Good results have been achieved using a two wire hydraulic hose for the hose 102; one and four wire hoses were found to be too flexible and too stiff, respectively.
The twist lock component of the locking mech~nism, indicated by 116 and shown in figs.5, 6, 9, 10, 11 and 13, for locking rotational movement has a movable key 118 carried by the disk 60. The key 118 is located in a slot 120 and is urged outwardly into an extended position by a biaser or spring 122 to engage one of a number of key lock stops 124 spaced about a portion of the inner periphery of the ring 62, thus locking rotational movement of the swivel plate 38 on the base plate 40. The spring 122 provides a fail safe mech~ni.~m as for the slide lock mech~ni.~m discussed above. In the preferred embodiment S the stops 124 are evenly circun~ele,llially spaced at about 10 degrees centre-to-centre relative to the axis 64, and extend over a quarter of the circumference of the ring 62 in correlation to the amount of rotation allowed by the slot 72. The number and spacing of the stops 124 may be changed base on design requirements.
The key 118 has an opening or slot 126 for receiving the free end of a pin 128 10 which is attached at the other end to metal collar 130. The collar 130 sits over the second brass fitting 106 and rod 108, and so the collar 130 and pin 128 rotate as the control lever 36 is moved between locked and unlocked positions. In lifting the lever 36 to the unlocked position, the pin 128 is swung counterclockwise (as viewed from the front of the seat device 20) into contact with the opening 126 and retracts the key 118 out of the stops 15 124 to permit rotational movement. When the lever 36 is returned to the locked position, the pin 128 is swung clockwise out of contact with the key 118, and the spring 122 pushes the key 118 outwardly to the key stops 124. To accommodate the swinging of the pin 128, one side ofthe key opening 126 is bevelled as indicated by 127.
The seat device 20 has several features for securing the base plate 40, and hence 20 the entire seat assembly 20, to the vehicle seat 24. Referring to figs.1 and 14, the rear end of the base plate 40 has an extension or tongue 132 for insertion under the lower edge of the vehicle back rest 26. With the tongue 132 wedged between the back rest 26 and the vehicle seat rest 22, the seat device 20 is prevented from tipping over forwardly. The base plate 40 also has apertures 134 for receiving flexible belts 28 with buckles 29 in the 25 manner shown in fig.1. The belts 28 restrain the seat 20 from sliding forward on the surface 22 during sudden stops of the automobile. It should be noted that mounting of the seat device 20 on the vehicle seat 24 in the manner shown should not interfere with the operation of other safety features of the automobile, such as use of the automobile's seat safety belt.
The base plate 40 is also provided with a convenient hand grip aperture 136 for transporting or carrying the seat device 20 when removed from the vehicle seat 24.
Preferably the cushion pad 32 has a thin ~hlmimlm backing or the like to secure the pad to the seat plate 30. In an alternate embodiment said securing might be achieved by means of a hook and loop material, such as VELCRO, for quick and easy replacement.
Hence, di~erenL cushion pads may be used on the same device 20 to suit di~elelll users.
When the seat plate is extended forwardly as shown in fig.8, a substantial part of the locking merh~ni~m on the rearward part of the swivel plate below is exposed. A thin ~l~lminllm plate or shield (not shown) may be placed above the exposed mech~ni~m to prevent a user's hands or cloths from interfering with operation of the seat device 20 and to prevent injury. The ~hlminllm shield may be secured to the retainer bolt (not shown) 10 which passes through opening 66 in the disk 60 as discussed earlier.
Use and operation of the seat device 20 may now be described in some greater detail. The seat device 20 is easily transported to the vehicle by hand (using aperture 136), placed upon the vehicle seat rest 22 by sliding the tongue 132 under the vehicle's back rest 26, and secured to the seat rest 22 by belts 28 as shown in fig.1. The lever 36 is 15 then lifted from the locked to the inclined unlocked position to release both the sliding and rotational movements and the seat plate 30 is brought to the position shown in fig.2c. The lever 36 is then returned to the horizontal locked position to fix the seat plate in the position shown. It will be appreciated that the seat plate 30 and the swivel plate 38 may have to be juggled slightly front to back and sideways, respectively, to allow the spring 20 biased slide lock pin 84 and the rotation lock key 118 to completely engage their respective keeper apertures.
A user st~ntling at the passenger vehicle doorway and facing outwardly may now be lowered onto the cushion pad 32 of the extended seat plate30, either with the help of an attendant or by simply using the vehicle door for some support. The user then lifts the 25 lever 36 to the unlocked position to slide the seat plate 30 backward to a position akin to fig.2d, and, either separately or concurrently with said sliding, rotates the swivel plate 38 counterclockwise to bring the legs into the car and the cushion pad 32 into the fig. 2a position. The lever is then placed into the horizontal lock position to lock the seat plate 30 and swivel plate 38 in place and the automobile's seat safety belt is fastened about the 30 user. This procedure may be followed by the user alone or with the aid of an ~ttencl~nt, as required. The reverse of the above described procedure is used to exit the vehicle.
Should the user wish to alter the seated position of fig.2a, for example to twist 10 or 20 degrees toward the vehicle's passenger side window, then the lever must be li~ed to the unlocked position, the seat plate twisted to the desired orientation, and the lever returned to the locked position. The seat plate may move or twitch slightly as the twist 5 lock key 118 engages the closest key lock stop 124. Likewise, if the user wishes to reach an item on the front dashboard of the vehicle, for example, the lever 36 should be lifted to allow the seat plate to be slid forward to the fig.2b position, at which position the seat plate may be locked by lowering the lever 36. It will be appreciated that if the lever is brought back to the horizontal locked position while the seat plate is intermediate the fully 10 retracted (fig.2a) and fully extended (fig.2b) positions, then the slide lock pin 84 will frictionally engage the slide lock plate 85 and provide resistance to any sliding movement until the pin arrives at and engages one of the keeper apertures 86, 88.
As mentioned earlier, the above described sliding and twisting movements may be done as separate movements or at the same time. An important advantage of the seat 15 device 20 is that the seat plate 30 may be rotated and slid, either concurrently or separately, and then positively locked in numerous di~elenl positions. The manual lever 36 is conveniently located for imrnediate control over said locking mech~ni.~m Another advantage is the bearing-less assembly used for the twist support component 44. In the pre~lled embodiment, for example, good results have been 20 obtained using all]mimlm for the swivel disk 60 and ring 62 elements, with the disk 60 having a thickness of only about 7.9 mm (5/16 inch). Not only does this provide for a lighter weight seat device 20 over the prior devices, but there are no ball bearings which wear or break and must be replaced. Height disadvantages of prior devices are also overcome.
The above description is intended in an illustrative rather than a restrictive sense and variations to the specific configuration and materials described may be apparent to skilled persons in adapting the present invention to specific applications. Such variations are intended to form part of the present invention insofar as they are within the spirit and scope of the claims below. For instance, satisfactory results may also be achieved by using 30 one belt 28 rather than two. In another variation, the belt buckles 29 may be replaced by clips which are secured to apertures underneath the vehicle seat rest 22.
FTFT n OF T~F TNVFNTION
The present invention relates to a portable movable seat assembly, and in particular to a seat assembly to assist disabled persons in the ingress and egress of chair structures 10 which are difficult to access, such as the passenger side seat of automobiles and the like.
RAcKGRouNn OF THF TNVENTION
As populations increase and age, there is a growing need for devices to help disabled persons, ranging from those with arthritis to paraplegics, to be able to access 15 (namely to sit down on and to stand up from) chair structures of various types and in various locations, ranging from a sofa in one own's home to automobile seats. Some chair structures are also becoming increasingly difficult to reach, a prime example of which is the automobile seat. Modern automobiles are generally small, compact and low to the ground, making it difficult for someone who is not very mobile to enter and exit such 20 automobiles.
Some of these problems have been addressed by the many me~ ed devices for making automobiles wheel-chair accessible, such as ramp like devices for lifting persons into the automobile. However, these devices are generally very bulky and often may only be used with larger vehicles such as vans Such devices are usually very expensive as well, 25 not counting the cost of having to specially purchase a large vehicle to accommodate the device. Once mounted, the ramp devices are not transferable for use elsewhere, such as in a home.
Less expensive and portable seating aids are known, but have seen limited use due to several disadvantages One example is the seat in US patent 3,185,523 (Morrill) where 30 a top pad is free to slide and rotate on a bottom pad This seat is rather dangerous since it lacks any mech~ni.cm for controlling or limiting such movement other than a single fiexible strap connected between the two pads.
21 147~7 Another example is the movable seat in US patent 3,043,622 (Milner). Although a bottom plate has a guide track for the top seat pad, the track lirnits the seat pad to a single type of arcing movement, for example the seat pad can not slide forward without having to rotate as well. In addition, it does not have a means of conveniently locking the seat 5 pad in one position on the track.
An improvement over these prior devices is found in C~n~ n patent 1,312,814 (Switzer) which shows a supporting mech~ni~m for a seat component on a base component. Although the supporting mech~ni~m allows for both rotational and sliding movement of the seat on the base, it also lacks certain desirable features. The seat can only 10 be locked in one position, namely only when the seat is fully retracted and facing forward.
Hence movement of the seat can not be locked when the seat is extended or rotated. The locking latch is inconvenient or difficult to reach since it is located behind the user, nor does it have a biaser or equivalent assembly for a positive lock. The supportingme~h~ni~m also raises the seat rather high off the base due to the ball race bearing 15 meçh~ni~m and rail assembly used at the time.
What is desired therefore is a portable seat assembly which overcomes the limitations and disadvantages of these other prior devices. Preferably the device should provide for concurrent or separate rotational and sliding movement of a seat on a base.
Such motion should be positively locked in numerous di~erenl positions. A manual20 controller should be provided so that a user may easily and conveniently control locking and unlocking of such movement. The device should be easy to transport and install in automobiles or the like, and not interfere with use of an automobile's other safety features, such as seat safety straps. The device should further have a support assembly which overcomes the height disadvantages of the prior devices, is relatively light weight, and 25 which reduces or elimin~tes the need for ball bearings.
SUMMARY OF THE INVENTION
According to the present invention there is provided a portable seat assembly for placement on a support surface of a chair structure comprising:
a seat plate;
a base plate for eng~ging said support surface;
a swivel plate intermediate said base plate and seat plate;
a support assembly for supporting the seat plate on the swivel plate and the swivel plate on the base plate, said support assembly having a twist support component for providing at least limited rotational movement of the swivel plate relative to the base plate, and a slide support component for providing limited fore and aft sliding movement of the 5 seat plate relative to the swivel plate either separately or concurrently with said rotational movement; and a locking mech~n;~m for selectively locking said rotational and sliding movements in a plurality of positions.
10 DFSC~rPTION OF THE DRAWINGS
Embodiments of the invention will now be described, by way of example onlyj withreference to the accompallyil1g drawings, wherein:
Figure 1 is a perspective view of a portable seat assembly mounted on a support surface of a chair structure, namely an automobile's passenger seat, according to a 15 prerelled embodiment ofthe present invention;
Figures 2a, 2b, 2c and 2d are plan views of the seat assembly of fig. 1 showing,respectively, a seat plate of the seat assembly in a fully retracted position, a fully extended position, rotated about 90 degrees clockwise in the fully extended position, and rotated about 90 degrees clockwise in the fully retracted position.
Figure 3 is a plan view of the seat assembly in fig. 1 showing the seat plate in a fully retracted position on a swivel plate and, in phantom outline, a slide support component of a support assembly, and a slide lock component and a portion of a twist lock component of a locking meçll~ni~m;
Figure 4 is an elevated side view of the seat assembly of fig.3;
Figure 5 is an elevated frontal view of the seat assembly taken along line 5-5 of fig.3;
Figure 6 is a partial cross-sectional view taken along line 6-6 of fig.3 showing a portion of the slide lock and twist lock components;
Figure 7 is a partial elevated side view taken along line 7-7 of fig.3 showing a30 portion of a m~nll~lly operable controller;
Figure 8 shows the seat assembly of fig.3 in a fully extended position;
Figure 9 is a plan view of the seat assembly in fig.1 with the seat plate removed, and showing in phantom outline a portion of a twist support component of the support assembly;
Figure 10 is an exploded view of the twist support component of the seat assembly 5 of fig.1, showing a portion of a twist lock component of the locking meçh~ni.~m;
Figure 11 is a plan view of the twist support component of fig.10;
Figure 12 is a side view of the twist support component of fig.11;
Figure 13 is a cross-sectional view along line 13-13 of fig.11; and Figure 14 is a plan view of a portion of the twist support component of fig.11 10 shown mounted on the base plate ofthe seat assembly ofthe present invention.
nF.SCRTPTION OF PRF.FFRRF.r~ F.MBOn~l~FNT
Reference is first made to fig.1 which shows a p.erel-ed embodiment of a portable seat assembly or device (indicated generally by reference numeral 20) placed on a support 15 surface 22 of a chair structure 24. Details of the device are omitted in this view, such as a m~n~l~lly operable lever 36 to be described later The chair structure 24 shown in fig.1 is the passenger side seat in a vehicle or passenger automobile having a back rest 26 and a head rest 27. The support surface 22 will therefore be referred to sometimes as a vehicle seat or seat rest. As shown, the seat device 20 is adapted for use on the automobile seat 20 24 by inclusion of one or more securing belts 28 as will be described later. However, it will be appreciated that the seat device 20 may be used, with slight modifications if needed, on support surfaces other than in vehicles, such as on chairs in residences, nursing homes or hospitals for example.
The seat device is designed to help a disabled or physically handicapped person to 2~ get into and out of a chair, such as the vehicle seat 24. Figures 2a-2d, which show the seat device 20 in plan view on the vehicle seat 24, illustrate the general movement and operation of the seat device. Details of the seat operation are set out later. Referring to fig.2a, a seat plate 30, having a removable padded upper support surface or cushion pad 32 shaped to receive a user, is shown locked in a fully retracted position and facing 30 forward (as indicated by directional arrow 34). A m~ml~lly operable controller or lever 36 is used to unlock the seat device 20, as described later, to allow the seat plate 30 to slide forward on a swivel plate 38 to a fully extended position shown in fig.2b, where sliding of 2~ 74787 the seat plate 30 may be locked if desired. Either separately or concurrently with the sliding motion, the seat plate 30 and the swivel plate 38 may be rotated about 90 degrees clockwise relative to a base plate 40 and the vehicle seat rest 22 to the position shown in fig.2c. The lever 36 is used to selectively lock the rotation of the swivel plate 38 relative 5 to the base plate 40 in the forward facing position (figs.2a and 2b), in the 90 degree rotated position (fig.2c), or in a plurality of rotated positions therebetween, as desired.
Figure 2d shows the seat plate 30 slid back on the swivel plate 38 to a fully retracted position. The fig. 2c and 2d positions will typically be used to help a user enter or exit the vehicle and the vehicle seat 24, and the fig.2a and 2b positions will typically be used help a 10 user get properly adjusted to a sitting position on the vehicle seat 24.
Details of the structure and mech~ni~m of the seat device 20 will now be described. Referring to figs.3, 4 and 5, the seat plate 30 is shown in the fully retracted position on the swivel plate 38 located intermediate the seat plate 30 and the base plate 40 which engages the vehicle seat rest 22. A support assembly for supporting the seat plate 15 30 on the swivel plate 38 and the swivel plate 38 on the base plate has two components:
(i) a slide support component (generally indicated by 42) for providing fore and aft sliding movement of the seat plate 30 on the swivel plate 38; and (ii) a twist support component 44 for providing rotational movement of the swivel plate 38 on the stationary base plate 40. The sliding movement may occur separately or concurrently with the rotational 20 movement, and visa versa, as explained below.
The slide support component 42 has a roller assembly 46 secured underneath the seat plate 30 and a guide assembly 47 secured on top of the swivel plate 38 to guide the sliding movement of the roller assembly 46. The roller assembly 46 has pairs of rollers 48 connected to generally vertical flanges 50 extending downwardly from opposite 25 longi~l~lin~l edges of the seat plate 30. The axles of each pair of rollers 48 are off-set to f~cilit~te mounting of the rollers on the flange 50. Also, the rollers 48 are located on opposite sides of the flange 50 to reduce stress concentrations in the vicinity of the roller/flange connection due to bending or twisting of the flange when weight is applied to the seat plate 30. Two pairs of rollers 48 are provided along each flange 50, one pair 30 toward the back of the seat plate 30 and the other pair in an area intermediate the front and back ends of the seat plate 30. More rollers could be used, but this is not prerelled due to increased weight of the seat device 20 and increased costs. It will be appreciated 2i 74787 that the fianges 50 may be substituted with individual brackets attached to the seat plate 30 for each pair of rollers 48, although this is also not plerelled due to the loss of the ing effect of the flanges on the seat plate 30.
The guide assembly 47 has a pair of parallel rails extending along opposite 5 longit~ n~l edges of the swivel plate 38 for receiving the rollers 48. Each rail is constructed of an inner L-shaped channel piece 52 and an outer Z-shaped channel piece 54. The rails formed by channel pieces 52, 54 confine the rollers 48 from side-to-side motion and from lifting off the swivel plate 38. At least one of the Z-shaped channel pieces 54 has a stop means to prevent escape of the rollers 48 from the rails in the form of 10 a set screw 56 at the front and an upwardly extending lip 58 at the rear of the Z-shaped channel piece.
The twist support component 44 of the support assembly, shown in figs.5 and 9 to14, uses a bearing-less (i.e. no ball bearings) assembly for rotating the swivel plate 38 on the base plate 40. The twist support component has a circular inner disk element 60 15 located within an outer ring element 62, said elements 60, 62 being rotatable relative to each other about a common axis of rotation 64. An opening 66, coincitling with the axis 64, receives a retainer bolt (not shown) which extends from the base plate 40 to the swivel plate 38 to retain the swivel plate on the base plate, thereby sandwiching the disk 60 therebetween. Good results have been achieved using a 5/16 inch elevator bolt with a 1 20 inch head countersunk into the durable plastic material of base plate 40 and capped with a lock nut (not shown) above the swivel plate 38. The disk 60 is fixed to the underside of the swivel plate 38 with a number of countersunk rivets (location indicated at 67), and the ring 62 is fixed to the top surface of the base plate 40 by a number of spaced rivets 68. To reduce frictional resistance between the metallic disk 60 and the plastic material of the 25 base plate 40, a pad of slide enhancing material 70 is located between the disk and the base plate. In the pr~relled embodiment, the pad 70 is of a size and shape comparable to the disk 60, and is made of a TEFLON material. The combined thickness of the disk 60 and the pad 70 should be greater than the thickness of the ring 62 to reduce or elimin~te any contact between the swivel plate 38 and the ring 62.
The twist support component 44 includes a stop means to limit the rotation of the swivel plate 38 relative to the base plate 40. The outer periphery of the disk 60 has a circumferential slot 72, and a limit pin 74 fixed to the base plate 40 protrudes through an aperture 71 in the pad 70 into the slot 72. Rotation of the swivel plate 38 is stopped when the pin 74 abuts or contacts an end of the slot 72 (as shown in fig.11, for example). In the pr~elled embodiment it is desired to limit the rotational movement to about 90 degrees, and so the slot 72 extends just over a quarter circumference of the disk 60 as shown.
S Referring specifically to fig.9, and to figs. 3, 5 and 8, a pair of oblong rollers 76 are provided at the front end of the swivel plate 38 and are adapted to run along the top surface of the base plate 40. The oblong rollers 76 enhance the above discussed rotational movement by limiting the deflection of the front end of the swivel plate 38 toward the base plate 40 when a user is seated on the seat device 20. Each roller 76 is supported on an 10 axle 78 fixed at its ends to the underside of the swivel plate 38. An opening 80 in the swivel plate 38 above each roller 76 avoids interference between the roller and plate 38.
The axles 78 are angled so that the rollers 76 follow a circular arc corresponding to the swivel plate's rotational movement. The rollers are preferably oblong to provide a relatively large roller in a vertically confined area. Two spaced rollers are used (as shown 15 in the figures) to provide stability to the swivel plate (i.e. to prevent the front of the swivel plate from rocking side to side during use).
The seat device 20 has a locking mech~ni~m for selectively locking the above mentioned rotational and sliding movements in a number of positions. Referring first to figs.3 and 5-8, the locking mech~ni~m has a slide lock component, generally indicated by 20 82, for locking the sliding movement of the seat plate 30 when the seat plate is fully n~led and fully retracted on the slide support component 42. The platform 30 is "fully"
retracted (fig.3) and "fully" extended (fig.8) when a movable pin 84 engages a front keeper or aperture 86, or a rear keeper 88, respectively, in the vertical leg of an L-shaped slide lock plate 85 ~tt~ched to the underside of the seat plate 30 and oriented parallel to 25 the roller guide channel 52. The "fully" retracted and extended positions are reached just before the rollers 48 would make contact with the sliding stop means, namely the set screw 56 and lip 58, respectively. The pin 84 is slidingly supported in an inverted C-shaped plate 90 with a spring 92 or equivalent biaser for urging the pin 84 toward the plate 85 and a locked position. Such a "fail safe" assembly ensures that the pin 84 will not 30 inadvertently ~i~eng~ge the keepers 86, 88. It will be appreciated that, if desired, more slide stop positions may be provided by adding further keepers on the slide lock plate 85.
The slide lock mech~ni~m 82 is controlled by the m~ml~lly operable lever 36 pivotally attached to the swivel plate 38 (best seen in figs.8 and 9) and an elongate coupler assembly 96 for operatively connecting the lever 36 to the locking mech~ni~m The lever has a first operative position generally parallel to the swivel plate (see fig.7) for locking S both the rotational and sliding movements of the seat device 20, and a second operative where the lever forms an acute angle with the swivel plate 38 (see fig.4) for unlocking both the rotational and sliding movements. In the pr~ ed embodiment, the lever is located at the left side of the seat device (i.e. to the left of a user when seated) and the acute angle is about 45 degrees for comfortable operation by a user when entering and 10 exiting the passenger side vehicle seat 24. The lever may be located elsewhere on the seat device 20 or a di~rerellt lever angle may be provided if need be. In addition, a cap 98 with detent system 99 (figs.3 and 7) provided at the base of the lever 36 allows a user to "feel"
when the lever has reached the first and second operative positions. A spring 100 keeps a required compressive force on the detent system 99.
The coupler assembly 96 has a flexible elongate hose 102 connected at one end to the lever 36 through a first brass fitting 104. The brass fitting 104 is serrated and the hose 102 is force fitted thereon. The other end of the hose 102 is also force fitted onto a second brass fitting 106 which is secured to an elongate rod 108 rotatably carried by a C-shaped plate 110 on the swivel plate 38 (see figs. 3, 5, 6 and 10). The front end of the rod 20 108 has a collar with a cam 112 fixed thereon. One end of a throw rod 114 is attached to the cam 112 and the other end is attached to the sliding lock pin 84. Hence movement of the lever 36 is transferred to the pin 84 by a twisting motion through the hose 102 and rod 108, and is then tran~l~ted to a linear or sliding motion by the cam 112 to the throw rod 114. For example, upward movement of the lever 36 to the second operative position or 25 unlocked position results in a pulling/tension force on the throw rod 114 which pulls the lock pin 84 away from the keepers 86, 88 in the slide lock plate 85 to allow sliding motion of the seat plate 30. Good results have been achieved using a two wire hydraulic hose for the hose 102; one and four wire hoses were found to be too flexible and too stiff, respectively.
The twist lock component of the locking mech~nism, indicated by 116 and shown in figs.5, 6, 9, 10, 11 and 13, for locking rotational movement has a movable key 118 carried by the disk 60. The key 118 is located in a slot 120 and is urged outwardly into an extended position by a biaser or spring 122 to engage one of a number of key lock stops 124 spaced about a portion of the inner periphery of the ring 62, thus locking rotational movement of the swivel plate 38 on the base plate 40. The spring 122 provides a fail safe mech~ni.~m as for the slide lock mech~ni.~m discussed above. In the preferred embodiment S the stops 124 are evenly circun~ele,llially spaced at about 10 degrees centre-to-centre relative to the axis 64, and extend over a quarter of the circumference of the ring 62 in correlation to the amount of rotation allowed by the slot 72. The number and spacing of the stops 124 may be changed base on design requirements.
The key 118 has an opening or slot 126 for receiving the free end of a pin 128 10 which is attached at the other end to metal collar 130. The collar 130 sits over the second brass fitting 106 and rod 108, and so the collar 130 and pin 128 rotate as the control lever 36 is moved between locked and unlocked positions. In lifting the lever 36 to the unlocked position, the pin 128 is swung counterclockwise (as viewed from the front of the seat device 20) into contact with the opening 126 and retracts the key 118 out of the stops 15 124 to permit rotational movement. When the lever 36 is returned to the locked position, the pin 128 is swung clockwise out of contact with the key 118, and the spring 122 pushes the key 118 outwardly to the key stops 124. To accommodate the swinging of the pin 128, one side ofthe key opening 126 is bevelled as indicated by 127.
The seat device 20 has several features for securing the base plate 40, and hence 20 the entire seat assembly 20, to the vehicle seat 24. Referring to figs.1 and 14, the rear end of the base plate 40 has an extension or tongue 132 for insertion under the lower edge of the vehicle back rest 26. With the tongue 132 wedged between the back rest 26 and the vehicle seat rest 22, the seat device 20 is prevented from tipping over forwardly. The base plate 40 also has apertures 134 for receiving flexible belts 28 with buckles 29 in the 25 manner shown in fig.1. The belts 28 restrain the seat 20 from sliding forward on the surface 22 during sudden stops of the automobile. It should be noted that mounting of the seat device 20 on the vehicle seat 24 in the manner shown should not interfere with the operation of other safety features of the automobile, such as use of the automobile's seat safety belt.
The base plate 40 is also provided with a convenient hand grip aperture 136 for transporting or carrying the seat device 20 when removed from the vehicle seat 24.
Preferably the cushion pad 32 has a thin ~hlmimlm backing or the like to secure the pad to the seat plate 30. In an alternate embodiment said securing might be achieved by means of a hook and loop material, such as VELCRO, for quick and easy replacement.
Hence, di~erenL cushion pads may be used on the same device 20 to suit di~elelll users.
When the seat plate is extended forwardly as shown in fig.8, a substantial part of the locking merh~ni~m on the rearward part of the swivel plate below is exposed. A thin ~l~lminllm plate or shield (not shown) may be placed above the exposed mech~ni~m to prevent a user's hands or cloths from interfering with operation of the seat device 20 and to prevent injury. The ~hlminllm shield may be secured to the retainer bolt (not shown) 10 which passes through opening 66 in the disk 60 as discussed earlier.
Use and operation of the seat device 20 may now be described in some greater detail. The seat device 20 is easily transported to the vehicle by hand (using aperture 136), placed upon the vehicle seat rest 22 by sliding the tongue 132 under the vehicle's back rest 26, and secured to the seat rest 22 by belts 28 as shown in fig.1. The lever 36 is 15 then lifted from the locked to the inclined unlocked position to release both the sliding and rotational movements and the seat plate 30 is brought to the position shown in fig.2c. The lever 36 is then returned to the horizontal locked position to fix the seat plate in the position shown. It will be appreciated that the seat plate 30 and the swivel plate 38 may have to be juggled slightly front to back and sideways, respectively, to allow the spring 20 biased slide lock pin 84 and the rotation lock key 118 to completely engage their respective keeper apertures.
A user st~ntling at the passenger vehicle doorway and facing outwardly may now be lowered onto the cushion pad 32 of the extended seat plate30, either with the help of an attendant or by simply using the vehicle door for some support. The user then lifts the 25 lever 36 to the unlocked position to slide the seat plate 30 backward to a position akin to fig.2d, and, either separately or concurrently with said sliding, rotates the swivel plate 38 counterclockwise to bring the legs into the car and the cushion pad 32 into the fig. 2a position. The lever is then placed into the horizontal lock position to lock the seat plate 30 and swivel plate 38 in place and the automobile's seat safety belt is fastened about the 30 user. This procedure may be followed by the user alone or with the aid of an ~ttencl~nt, as required. The reverse of the above described procedure is used to exit the vehicle.
Should the user wish to alter the seated position of fig.2a, for example to twist 10 or 20 degrees toward the vehicle's passenger side window, then the lever must be li~ed to the unlocked position, the seat plate twisted to the desired orientation, and the lever returned to the locked position. The seat plate may move or twitch slightly as the twist 5 lock key 118 engages the closest key lock stop 124. Likewise, if the user wishes to reach an item on the front dashboard of the vehicle, for example, the lever 36 should be lifted to allow the seat plate to be slid forward to the fig.2b position, at which position the seat plate may be locked by lowering the lever 36. It will be appreciated that if the lever is brought back to the horizontal locked position while the seat plate is intermediate the fully 10 retracted (fig.2a) and fully extended (fig.2b) positions, then the slide lock pin 84 will frictionally engage the slide lock plate 85 and provide resistance to any sliding movement until the pin arrives at and engages one of the keeper apertures 86, 88.
As mentioned earlier, the above described sliding and twisting movements may be done as separate movements or at the same time. An important advantage of the seat 15 device 20 is that the seat plate 30 may be rotated and slid, either concurrently or separately, and then positively locked in numerous di~elenl positions. The manual lever 36 is conveniently located for imrnediate control over said locking mech~ni.~m Another advantage is the bearing-less assembly used for the twist support component 44. In the pre~lled embodiment, for example, good results have been 20 obtained using all]mimlm for the swivel disk 60 and ring 62 elements, with the disk 60 having a thickness of only about 7.9 mm (5/16 inch). Not only does this provide for a lighter weight seat device 20 over the prior devices, but there are no ball bearings which wear or break and must be replaced. Height disadvantages of prior devices are also overcome.
The above description is intended in an illustrative rather than a restrictive sense and variations to the specific configuration and materials described may be apparent to skilled persons in adapting the present invention to specific applications. Such variations are intended to form part of the present invention insofar as they are within the spirit and scope of the claims below. For instance, satisfactory results may also be achieved by using 30 one belt 28 rather than two. In another variation, the belt buckles 29 may be replaced by clips which are secured to apertures underneath the vehicle seat rest 22.
Claims (31)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A portable seat assembly for placement on a support surface of a chair structure comprising:
(a) a seat plate;
(b) a base plate for engaging said support surface;
(c) a swivel plate intermediate said base plate and seat plate;
(d) a support assembly for supporting the seat plate on the swivel plate and theswivel plate on the base plate, said support assembly having a twist support component for providing at least limited rotational movement of the swivel plate relative to the base plate, and a slide support component for providing limited fore and aft sliding movement of the seat plate relative to the swivel plate either separately or concurrently with said rotational movement; and (e) a locking mechanism for selectively locking said rotational and sliding movements in a plurality of positions.
(a) a seat plate;
(b) a base plate for engaging said support surface;
(c) a swivel plate intermediate said base plate and seat plate;
(d) a support assembly for supporting the seat plate on the swivel plate and theswivel plate on the base plate, said support assembly having a twist support component for providing at least limited rotational movement of the swivel plate relative to the base plate, and a slide support component for providing limited fore and aft sliding movement of the seat plate relative to the swivel plate either separately or concurrently with said rotational movement; and (e) a locking mechanism for selectively locking said rotational and sliding movements in a plurality of positions.
2. The seat assembly of claim 1 wherein the locking mechanism has a slide lock component for locking the sliding movement of the seat plate at least when the seat plate is in a fully extended and fully retracted position on said slide support component of the support assembly.
3. The seat assembly of claim 2 wherein the locking mechanism includes a biaser for urging said slide lock component into a locked position.
4. The seat assembly of claim 3 wherein the slide lock component provides resistance to the sliding movement of the seat plate between said fully extended and fully retracted positions by frictionally engaging said slide support component when said locking mechanism is set to a locked position.
5. The seat assembly of claim 4 wherein said slide lock component includes a movable pin for engaging keepers in said slide support component to lock said sliding movement when said locking mechanism is set to a locked position, and to disengage from said keepers when said locking mechanism is set to an unlocked position.
6. The seat assembly of claim 5 wherein said biaser comprises a spring for urging said movable pin toward the slide support component and into engagement with said keepers.
7. The seat assembly of claim 1 wherein said twist support component for rotational movement comprises a bearing-less assembly which includes a disk element disposed within a ring element, said disk and ring elements being rotatable relative to each other about a common axis of rotation.
8. The seat assembly of claim 7 wherein said disk element is rotatably fixed relative to the swivel plate and said ring element is rotatably fixed relative to the base plate.
9. The seat assembly of claim 8 wherein a slide enhancing material is located between said disk element and said base plate to facilitate rotation of the disk element on the base plate.
10. The seat assembly of claim 9 wherein said slide enhancing material comprises a TEFLON pad of corresponding shape to said disk element.
11. The seat assembly of claim 7 wherein said support assembly carries a portion of a twist lock component of said locking mechanism for locking said rotational movement, said twist lock component comprising:
a movable key carried by said disk element; and a plurality of key lock stops carried by said ring element adjacent said disk element, wherein said key is extended to engage one of said key lock stops to lock the rotational movement of said swivel plate, and said key is retracted to disengage the key lock stop to permit said rotational movement.
a movable key carried by said disk element; and a plurality of key lock stops carried by said ring element adjacent said disk element, wherein said key is extended to engage one of said key lock stops to lock the rotational movement of said swivel plate, and said key is retracted to disengage the key lock stop to permit said rotational movement.
12. The seat assembly of claim 11 wherein a biaser is provided for urging said key into the extended position, and said key lock stops are evenly spaced about a portion of an inner periphery of said ring element.
13. The seat assembly of claim 12 wherein said key lock stops extend over a quarter circumference of said inner periphery.
14. The seat assembly of claim 11 wherein movement of said key is controlled by a swingable pin which engages a slot in said key, said pin being attached to an elongate coupling assembly which is operatively connected to a controller for manual operation by a user of the seat assembly.
15. The seat assembly of claim 7 wherein said support assembly includes a stop means for limiting rotational movement of the swivel plate relative to the base plate comprising:
a circumferential slot in a portion of the outer periphery of said disk element; and a stopper, fixed to one of said base plate or said swivel plate, adapted to ridewithin said slot, wherein further rotational movement is prevented when said stopper abuts an end of said slot.
a circumferential slot in a portion of the outer periphery of said disk element; and a stopper, fixed to one of said base plate or said swivel plate, adapted to ridewithin said slot, wherein further rotational movement is prevented when said stopper abuts an end of said slot.
16. The seat assembly of claim 15 wherein said slot extends over a quarter circumference of said outer periphery.
17. The seat assembly of claim 1 wherein said slide support component of the support assembly comprises:
(a) a roller assembly secured to an underside of said seat plate;
(b) a guide assembly secured to said swivel plate to guide said roller assembly on said swivel plate for said fore and aft sliding movement.
(a) a roller assembly secured to an underside of said seat plate;
(b) a guide assembly secured to said swivel plate to guide said roller assembly on said swivel plate for said fore and aft sliding movement.
18. The seat assembly of claim 17 wherein said roller assembly comprises at least two pairs of spaced rollers extending from each opposite longitudinal edge of said seat plate, and said guide assembly comprises a pair of spaced parallel rails for receiving said rollers and stop means for limiting fore and aft movement of said rollers in said rails.
19. The seat assembly of claim 18 wherein the axles of each roller in said pair of rollers are off-set.
20. The seat assembly of claim 1 wherein said support assembly further includes a pair of spaced rollers connected to a front end of said swivel plate and adapted to run on said base plate to support said front end and maintain a clearance from the base plate.
21. The seat assembly of claim 20 wherein the axis of rotation of each of said rollers is oriented to allow the roller to follow an arc of rotation of said swivel plate.
22. The seat assembly of claim 1 further comprising a manually operable controller operatively engaged to the locking mechanism for controlling said selective locking.
23. The seat assembly of claim 22 wherein said controller has at least a first operative position for locking both said rotational and sliding movements, and a second operative position for unlocking both said rotational and sliding movements.
24. The seat assembly of claim 23 wherein when said controller is placed in said first operative position, the locking mechanism provides resistance to the sliding movement of the seat plate until said slide support component is locked in either a fully extended or fully retracted position.
25. The seat assembly of claim 23 wherein said controller comprises a lever pivotally attached to said swivel plate, an elongate coupler assembly for operatively connecting the lever to the locking mechanism, and a detent means for indicating to a user when said first and second operative positions are reached.
26. The seat assembly of claim 25 wherein said lever is located to the left of a user seated on said seat plate, and wherein in said first operative position the lever is generally parallel to said swivel plate and in said second operative position the lever forms an acute angle with said swivel plate.
27. The seat assembly of claim 1 wherein said base plate is adapted to receive at least one belt for securing the base plate to said support surface of the chair structure.
28. The seat assembly of claim 1 wherein said base plate includes an extension formed on a rear end thereof for insertion under a lower edge of a back rest of said chair structure to assist in retaining said seat assembly in place upon the support surface of the chair structure.
29. The seat assembly of claim 28 wherein said extension includes a gripping means for carrying said seat assembly when removed from said chair structure.
30. The seat assembly of claim 28 wherein said chair structure comprises an automobile seat.
31. The seat assembly of claim 1 wherein said seat plate includes a removable padded upper surface shaped to receive a user.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002174787A CA2174787A1 (en) | 1996-04-23 | 1996-04-23 | Portable movable seat |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002174787A CA2174787A1 (en) | 1996-04-23 | 1996-04-23 | Portable movable seat |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2174787A1 true CA2174787A1 (en) | 1997-10-24 |
Family
ID=4158045
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002174787A Abandoned CA2174787A1 (en) | 1996-04-23 | 1996-04-23 | Portable movable seat |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2174787A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011050413A1 (en) * | 2009-10-27 | 2011-05-05 | Robert Anders Nillson | An item of furniture |
| CN109223329A (en) * | 2018-10-31 | 2019-01-18 | 江西科技学院 | It gets on or off the bus auxiliary device and the automobile containing the auxiliary device of getting on or off the bus |
-
1996
- 1996-04-23 CA CA002174787A patent/CA2174787A1/en not_active Abandoned
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011050413A1 (en) * | 2009-10-27 | 2011-05-05 | Robert Anders Nillson | An item of furniture |
| US8899682B2 (en) | 2009-10-27 | 2014-12-02 | Smart Seating International Pty. Ltd. | Item of furniture |
| CN109223329A (en) * | 2018-10-31 | 2019-01-18 | 江西科技学院 | It gets on or off the bus auxiliary device and the automobile containing the auxiliary device of getting on or off the bus |
| CN109223329B (en) * | 2018-10-31 | 2023-03-14 | 江西科技学院 | Getting-on/off auxiliary device and automobile comprising same |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued | ||
| FZDE | Discontinued |
Effective date: 19990423 |