Patent Publication Number: US-6659556-B2

Title: Reclining motorized multi-position chair with rocking and pivoting action

Description:
TECHNICAL FIELD 
     The present invention relates to the general field of household furniture and is particularly concerned with a motorized, multi-position reclining chair having rocking and pivoting action and other features to permit ease of access for use of such chairs. 
     BACKGROUND ART 
     In daily life, chairs are used extensively. Therefore, chairs are typically designed ergonomically to meet the needs of a user&#39;s comfort. The requirements for the design of chairs are becoming increasingly stringent with regard to the correct adjustment of the chair. Indeed, the individual adaptation to the user in order to achieve a correct and comfortable sitting position is now considered crucial. This requirement is important since chairs are typically used over a long period time, with the result that an incorrect adjustment feels uncomfortable and leads to potentially harmful sitting positions. It has thus been long recognized that different users generally have different customs and preferences of sitting, and particularly so with older people. Therefore, there is a need for a chair which can be adjusted according to the users&#39; requirements and preferences. 
     One particularly popular type of chair which can be adjusted to suit the preferences of given individuals is the so-called reclining chair. These chairs are typically provided with a separate linkage mechanism for permitting the seated occupant to selectively actuate an extensible leg rest assembly and/or produce reclining angular movement of a seat assembly between upright and reclined positions. There are numerous linkage arrangements which have been proposed in the prior art for controlling the operation of the reclining mechanism for such chairs, as evidenced both by the extensive patent literature and the numerous commercial chairs which are to be found on the market. 
     A reclining chair generally takes one of two forms. In a so-called two-way chair, the seat and back are rigidly connected; in moving from the upright position to the fully reclined position, the leg rest rises and the seat and back tilt backwards as a unit. In a three-way chair, the back is pivoted to the seat; in moving from the upright position to the fully reclined position, there is an additional tilt of the back relative to the seat. In both types of chairs, the seat is sometimes made to move forward in reclining positions so that the chair can be placed near a wall even though the seat and back tilting causes the top of the back to move toward the wall; by having the seat move forward, the chair need not be placed several feet from the wall. However, this could provide for an uncomfortable chair. 
     Moveable leg rests for reclining chairs are also well known in the prior art. A moveable leg rest for reclining chairs may automatically be actuated in response to chair movement or may be hand-actuated to extend between a position of use to a retracted or storage position. In the extended position, the leg rest is disposed generally horizontally relative to the floor level in front of the front edge of the chair. In the retracted position, the leg rest is generally disposed in a vertical position and is usually retracted up against the front edge of the chair beneath the seat. 
     With the leg rest in the extended position, a user may lean back or recline in a chair and place his or her legs on the leg rest, thereby orienting the legs in an outstretched and generally horizontal position. With the leg rest in the retracted attitude, the user sits in the chair normally with his/her feet on the floor, thereby permitting the chair to be used in the usual fashion since the leg rest is retracted up against the chair behind the chair user&#39;s legs. 
     One common type of leg rest is a type that is supported on the frame of the chair. This type of leg rest is typically actuated by a pantographing linkage type of mechanism between its retracted and extended positions. This type of mechanism includes several linkages which are connected together in scissors fashion to move the foot rest from its relatively vertical position when retracted to a horizontal position when extended and to hold the foot rest in the horizontal position. 
     This type of actuating mechanism is usually quite complicated, in part because of the requirement that the linkages not only extend the leg rest, but that they also move the leg rest from a vertical to a horizontal position. 
     Another type of leg rest is one that is supported by the chair seat rather than the frame of the chair. The advantage of this arrangement is that the leg rest and seat relationship stay the same throughout all positions of the seat. However, this type of leg rest also generally uses the complicated pantographing actuating mechanism to extent and retract the leg rest. Furthermore, the actuating mechanism in this type of seat and leg rest arrangement is complicated by the need in many cases to mount the drive means for the actuating mechanism on the chair frame so that the drive means does not move and interfere with other parts of the chair such as upholstery, legs and frame members. 
     The scissors type of linkage also has other notable disadvantages, foremost amongst which is the safety problem presented by the scissoring action of the linkage itself. Indeed, this scissoring action is capable of causing serious injury such as to a finger or other extremity caught in the mechanism when it is retracted quickly from its extended position. Additionally, the multiplicity of pivot joints in the scissors linkage are all subject to wear and fatigue, often resulting in loosening of the mechanism, with the consequent failure of the foot rest to assume a tightly retracted condition with the chair. Such scissors linkages also have relatively little lateral strength and are subject to easy damage from sideways forces applied to the foot rest when extended. They are also difficult and costly to repair. 
     Another type of component commonly found, and which selectively locks and unlocks moveable portions to provide a shiftable foot rest, is the so-called Bowden cable assembly which includes a shiftable cable partially received within a tubular jacket. These Bowden cable assemblies are typically coupled with a pivotal handle for shifting the cable between the first and second positions. The handle can be coupled with a rectangular support base which is typically mounted in a chair by cutting a rectangular aperture in a wall of the chair and inserting the rectangular base into the aperture. These types of assemblies are notorious for various drawbacks, including that they cannot be adjusted to various selected positions of comfort because the rectangular aperture precludes any clockwise or counterclockwise rotation of the base with respect to the plane of the wall in which it is retained. Also, the control handle may remain in an awkward extended position after the handle has been manipulated to shift the cable for its primary control purposes due to the resulting friction between the cable and the Bowden jacket. 
     The hereinabove-mentioned disadvantages associated with conventional mechanically controlled tilt adjustment assemblies are further compounded by the prior art when motorizing such reclining chairs. Although there have been numerous attempts to motorize reclining chair operation, the approach which has generally been taken is to provide a motor to achieve mechanically controlled motion. In other words, one or more motors are added to an existing design in order to aid motion of the several elements, but the physical constraints of the prior art linkages are not overcome. What has been done is to adapt motors to existing designs rather than to recognize that the use of a motor allows new types of motion. In those conventional reclining chairs, or recliners, which do not include special leverage, the motor force is derived by the occupant pushing against the back of the chair. The back starts to move, and the linkage mechanisms in the chair cause the leg rest to rise and the seat to be tilted. Prior art motorized configurations have simply assisted this type of sequencing. The present invention takes into account the fact that the provision of a motor to provide thrust not only allows the use of greatly simplified linkages, but also permits a new type of sequencing to achieve further additional advantages. 
     Another drawback associated with conventional motorized reclining chairs relates to the fact that the proposed mechanisms often preclude rocking and pivoting of the chair relative to its base. This has proven to be most unacceptable since it greatly deters the overall appeal of such chairs. Furthermore, some motorized prior art chairs only allow for tilting of the chair to a preset and predetermined number of angular relationships between the moveable sections of the chair, and this has been proven to be unacceptable to certain users. Accordingly, there exists a need for an improved tilt adjustment assembly for reclining chairs, which is provided by the present invention. 
     SUMMARY OF INVENTION 
     Advantages of the present invention include the fact that the proposed motorized reclining chair and associated tilt adjustment assembly allow greatly simplified linkages to be employed, and further control a sequencing which is far more advantageous than that exhibited by prior art reclining chairs in general and motorized reclining chairs in particular. Furthermore, the proposed tilt adjustment assembly is specifically designed so as to be easily retrofittable to most conventional prior art mechanical reclining chairs. The tilt adjustment assembly allows for continuous angular adjustment over a predetermined range as opposed to the discrete angular adjustment required by prior art designs. The proposed tilt adjustment assembly further increases the range of angular motion afforded by conventional designs. Still further, the proposed tilt adjustment assembly is adapted to maintain a proper tension in the linkage mechanisms so as to prevent undue slacking of the leg rest. This feature can prove to be particularly important since, after a chair has been broken-in through usage, the leg rest could refuse to stay put when fully retracted and adopt a frowning look. Recliner mechanisms generally are constructed to operate smoothly through their motions. When the leg rest suddenly becomes loose, it can be banged against the floor when retracted by the user, giving the user an abrupt change in the feel of the movement, which is discomforting. 
     Still further, the proposed tilt adjustment assembly of the present invention also allows the chair to rock and pivot about its base. This is believed to be a major advantage over prior art designs. The proposed chair also has auxiliary features such as the optional presence of an auxiliary retractable tray, the optional presence of stabilizing abutment pads and the optional presence of an arm rest design adapted to facilitate extraction and insertion from and to the chair. 
     Another disadvantage of the prior art recliner chairs or chairs that swivel and rock is that it is sometimes difficult for certain user persons to disembark from the chair due to the fact that the chair is freely tiltable and rotatable. It is, therefore, another feature of the present invention to provide such chairs with a capability of positive engagement with a floor surface when a user person wishes to disembark from the chair. 
     According to the above advantages of the present invention, from a broad aspect, there is provided a tilt adjustment assembly for a motorized reclining chair having a base frame adapted for rest on a floor surface. A seat and a back articulated support linkage are interconnected together for displacement of the seat and back of a recliner chair, there being one of the said seat and back articulated support linkages on each of opposed sides of the base frame and secured thereabove on a respective linkage support frame. An intermediate frame is mounted on the base frame through spring attachment means to impart a rocking motion to the chair. A pair of foot rest linkages interconnect each of the seat articulated support linkages to a foot rest plate. The tilt adjustment assembly comprises a motor-operated actuating rod secured at a free end to a sliding member to guidingly displace the sliding member along a straight axis in a fixed plane and to any desired position along the axis. A pivotal link arm is pivotally secured at one end to the sliding member. A transverse linkage securing rod is secured to a second end of the pivotal link arm and extends transversely thereto. The transverse securing rod has opposed ends pivotally connected to an intermediate link arm of a respective one of the pair of foot rest linkages. Tensioning means is secured to each of the pair of foot rest linkages for applying a restoring force to the foot rest plate towards a foot rest retracted position. 
     According to a further broad aspect of the present invention, there is provided a motorized reclining and rocker chair which incorporates the above-described tilt adjustment assembly. The chair has opposed side arms. Each of the side arms has a base elevated from the base frame above a floor surface, a front vertical frame secured to the base, and an arm rest frame secured to the front vertical frame. A floor-engaging leg is secured to the base under the front vertical frame and spaced from a floor surface. The floor-engaging legs engage a floor surface when a user person applies a downward force on the side arm rest forwardly thereof, causing the chair to tilt forward and providing direct lifting support to a user person between the front vertical frame and a floor surface to stabilize the chair and provide positive disembarkation support to the user person. 
     According to a further broad aspect of the present invention, there is provided a motorized reclining, lifting and tilting rocker chair which incorporates the tilt adjustment assembly. The chair has a lifting and tilting mechanism which is secured to side arms thereof and disposed on opposed outer sides of the seat and back articulated support linkages. Each lifting and tilting mechanism has a displaceable floor-engaging member displaceable from a retracted elevated position, where the chair can recline and rock, and to a lowered floor-engaging position where the chair is arrested from reclining and rocking. A linkage is secured between the floor-engaging member and an associated one of the side arms. A motor-actuated extendible member is secured at one end to a stationary pivot, secured to the floor-engaging member, and at an opposed end to a link pivot connection of the linkage to actuate the displaceable floor-engaging member to firstly cause the floor-engaging member to lower and engage a floor surface and then cause the chair to tilt forwardly. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     A preferred embodiment of the present invention will now be disclosed, by way of an example thereof, with reference to the following drawings, in which: 
     FIG. 1 is a perspective view which illustrates a conventional reclining chair base on which the tilt adjustment assembly in accordance with the present invention may be mounted, the chair being shown with its foot rest at a retracted position; 
     FIG. 2 is a perspective view which illustrates a conventional reclining chair base on which a tilt adjustment assembly in accordance with the present invention may be mounted, the chair being shown with its foot rest in an extended position; 
     FIG. 3 is a perspective view which illustrates the chair base shown in FIG. 1 incorporating the tilt adjustment assembly of the present invention; 
     FIG. 4 is a perspective view showing the chair base of FIG. 2 equipped with the tilt adjustment assembly of the present invention; 
     FIG. 5 is a side elevational view of the chair base and tilt adjustment assembly shown in FIG. 3; 
     FIG. 6 is a side elevational view of the chair base and tilt adjustment assembly shown in FIG. 4; 
     FIG. 7 is a partial exploded view, with sections taken out, and illustrating part of the tilt adjustment assembly of the present invention about to be mounted to a conventional tilting chair base, the leg rest part of the chair being shown in a retracted position; 
     FIG. 8 is a partial exploded view, with sections taken out, and illustrating part of the tilt adjustment assembly of the present invention about to be mounted to a conventional tilting chair base, the leg rest part of the chair being shown in an extended configuration; 
     FIG. 9A is a perspective view of a recliner chair constructed in accordance with the present invention and wherein floor-engaging legs are provided for stability and positive engagement with a floor surface for disembarkation; 
     FIG. 9B is an exploded view of the leg; 
     FIG. 10A is a view similar to FIG. 9, showing a person disembarking from the chair; 
     FIGS. 10B and 10C are exploded views of the leg; 
     FIGS. 11A to  11 D are side views showing the construction operation of a lifting and tilting mechanism secured to the side arms of the reclining rocker chair; 
     FIG. 12 is a side view of the lifting and tilting mechanism; 
     FIG. 13A is a top view of the lifting and tilting mechanism; 
     FIG. 13B is a front view of the lifting and tilting mechanism; 
     FIGS. 14A to  14 C are side views showing the lifting and tilting mechanism of FIG. 12 at various positions of its full actuated cycle; and 
     FIGS. 15A to  15 C are simplified perspective views showing a person sitting in the motorized reclining and rocker chair with the lifting and tilting mechanism actuated to position the chair to an occupant disembarking or embarking position. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring to FIGS. 1 and 2, there is shown in the corresponding perspective views a conventional reclining chair linkage mechanism and attachment  10  showing its foot rest respectively at a retracted and extended position. The reclining chair linkage mechanism and attachment  10  includes base legs  12  adapted to rest on a floor surface. A linkage support frame  14  is pivotally and rotatably mounted to the base legs  12 , by means well known in the art, such as the rotating guide frame  13  as shown in FIG. 3, so as to allow rocking and pivoting relative motion between the linkage support frame  14  and legs  12 . The chair rocks on the springs  22  and swivels on the swivel assembly  9  shown in FIG.  5 . Seat and back support linkages  16 ,  18  are attached to the frame  14  by intermediate frame members  20 , preferably through the use of a suspension system such as helicoidal-type springs  22   
     A foot rest plate  24  is pivotally coupled to the linkage support frame  14  using foot rest linkage arm assembly  26  so as to allow the foot rest plate  24  to pivot between its retracted position shown in FIG.  1  and its extended position shown in FIG.  2 . It should be understood that the reclining chair base  10  shown in FIGS. 1 through 8 is only an example of the type of chair frame that can be used with the present invention. Various modifications, including other pantograph linkage configurations, could be used without departing from the scope of the present invention. 
     Referring now more specifically to FIGS. 7 and 8, there are shown some of the components of the tilt adjustment assembly  27  of the present invention. The tilt adjustment assembly includes a sliding skate component  28  mounted within a guiding means for reciprocating action. The guiding means preferably takes the form of a guide plate  30  provided with a longitudinal guiding groove  32  extending therealong. The sliding skate  28  is configured and sized so as to slide within the guiding groove  22 . 
     The guide plate  30  is secured to a mounting plate  34  adjacent to a first longitudinal end thereof. In turn, the mounting plate  34  is adapted to be mechanically coupled to rods of the intermediate frame member  20 . 
     An actuating means for actuating the reciprocating action of the sliding skate  28  is further provided and secured to the mounting plate  34 . The actuating means preferably takes the form of a piston cylinder  36  mechanically coupled to a drive motor  38 . It is also conceivable that the piston could be replaced by an endless screw drive to axially rotate an endless screw and displace the sliding skate  28 . 
     A lever arm  40  is pivotally coupled to the sliding skate component  38  at a free end thereof opposite its connection with the piston rod  30 ′ of the piston  36  (see FIG.  8 ). The linkage arm  40  is attached to the skate component  38  so as to allow relative pivotal action therebetween. The linkage arm  40  is adapted to pivot between a retracted position wherein it lies in a generally colinear relationship to the longitudinal axis of the piston  36  and to an extended position wherein it lies in a generally angled relationship relative to the longitudinal axis of the piston  36 , as shown in FIG.  8 . 
     A first linkage securing rod  42  is solidly secured to the distal end of the lever arm  40  and extends substantially perpendicular relative thereto. A second linkage securing rod  44  is secured to the aperture  61  of the intermediate link arm  26 ″, which is connected to the foot rest plate  24  intermediate the distal segments of the assembly, as shown in FIG.  4 . 
     A tensioning means maintains a predetermined tension in the linkage assemblies  26  during their movement between the retracted and extended positions. The tensioning means preferably takes the form of tensioning helicoidal-type springs  46  attached at a first longitudinal end thereof by attachment bolts  48  to a bolt attachment aperture  50  provided in the leg rest linkage proximal segment  26 ′ and at an opposed longitudinal end thereof to an adjacent linkage segment  60 . 
     The tilt adjustment assembly  27  preferably further includes abutment brackets  52  and anchoring components  54 . The anchoring components  54  are adapted to anchor various linkage components of the seat support linkage  16  and coordinate their relative movement therebetween. The brackets  52  prevent rocking movement of the chair when the foot rest linkage arm assembly is extended, as shown in FIG.  6 . 
     In use, a hand-actuable control means, well known in the art, is used for selectively activating the motor  38  and the associated piston cylinder  36 . When the cylinder  36  is activated towards its extended position as shown in FIGS. 4,  6  and  8 , movement of the skate component  28  attached thereto is transmitted to the lever arm  40  and to the first linkage securing rod  42 . The pantograph configuration of the leg rest linkage arms  26  causes the latter to extend to its extended position, allowing the foot rest plate  24  to move to its substantially horizontal position. The second linkage securing rod  44  allows for coordination of the deployment of the foot rest linkage arms  26  and ensures stability of the mechanism. 
     As mentioned previously, the tilt adjustment assembly allows an intended user to position the foot rest plate  24  at any intermediate position between the retracted and extended configurations by controlling the motor, and therefore the extension of the piston rod  30 ′, and consequently the position of the skate component  28  on the guide plate  30  and thus the angular position of the foot rest linkage arm assembly  26 . Once the skate component  38  has reached a position substantially midway between its longitudinal end points, the pantograph configurations of the linkages  16  and  18  allow for the reclining of the back rest section of the seat. When the tilt adjustment assembly is in the retracted position, shown in FIG. 5, the proposed mechanism allows for full tilting and pivotal action of the seat relative to its base while the assembly is in its extended configuration, as shown in FIG.  6 . The rocking movement is temporarily prevented by the abutment brackets  52  which abut on the frame members  20  so as to increase stability of the overall seat. 
     With reference now to FIGS. 9 and 10, there is shown generally at  65  a motorized reclining and rocker chair incorporating the tilt adjustment assembly  27  of the present invention, but not shown in these illustrations. The reclining and rocker chair  65  has opposed side arms  66 . Each of these side arms has a base  67  elevated from the base frame  13  above the floor surface  68 . The side arms also have a front vertical frame  69  secured to the base  67 , and an arm rest frame  70  which is secured to the front vertical frame  69 . 
     The improvement resides in that a floor-engaging leg  71  is secured to the base frame  67  under the front vertical frame  69  and has a lower edge  72  spaced from the floor surface  68 . This lower edge  72  engages the floor surface  68  when the user person  73  applies a downward force on the arm rests in the direction of arrow  74 , as shown in FIG. 10, and forwardly of the arm rest to cause the chair to tilt forward in the direction of arrow  75 , and providing direct connection with the floor surface  68  to stabilize the chair and provide positive disembarkation support to the user person  73 . Accordingly, this prevents the chair from swiveling sideways or tilting, which could cause injury to a frail or aged person. 
     Referring now to FIGS. 11A to  11 D, there is shown generally at  80  the chair lifting and tilting mechanism. As herein shown, the mechanism is secured to opposed sides of the chair frame below the side arms. This is better illustrated in FIG. 15A, wherein the chair  81  is provided with an enclosure  82  on the side arm frame  83  and space below the side arms  84 . The enclosure  82  conceals the lifting and tilting mechanism  80 , as can be seen from FIGS. 15B and 15C. When the lifting and tilting mechanism is actuated by the occupant  85  of the chair, the lifting and tilting mechanism  80  causes the chair to rise and tilt forward, as shown in FIGS. 15B and 15C, whereby the occupant  85  is disposed at a substantially vertical position to make it easy for the occupant to disembark or to embark the chair. The mechanism  80  is actuated by a switch accessible to the occupant and not illustrated herein, but obvious to a person skilled in the art. 
     With additional reference now to FIGS. 12 to  14 C, there will be described the construction and operation of the lifting and tilting mechanism  80 . As herein shown, the mechanism is disposed on opposed outer sides of the seat and back articulated support linkages  16  and  18 , as shown in FIGS. 1 and 2. Seeing that the lifting and tilting mechanisms secured on opposed sides of the chair are identical, only one will be described herein. 
     The lifting and tilting mechanism has a displaceable floor-engaging member  86  which is essentially a longitudinal flat narrow metal plate. This plate is displaceable by the linkage from a retracted elevated position, as shown in FIG. 11A, where the chair can recline and rock, and to a lowered floor-engaging position, as shown in FIG. 11B, where the chair is arrested from reclining and rocking due to the interconnection of the chair with the floor through the linkage  80 . 
     As better shown in FIGS. 12 to  14 C, the lifting and tilting mechanism is provided with a motor-actuated extendible member  87 , which consists essentially of a threaded rod  88  which is threadably engaged in a rotatable cylinder  89 . The cylinder  89  is connected to an electric motor  90  through a gear coupling located in a gear box  91 . The electric motor  90  has a gear secured to a driveshaft thereof whereby to cause relative rotation between the cylinder  89  and the threaded rod  88 , whereby to cause the combination of the cylinder and rod to expand and retract to actuate the linkage and displace the chair. The extendible member  87  is pivotally secured at one end to a stationary pivot  92 , which is secured to a post  93  connected to the floor-engaging member  86 . The opposed end of the motor-actuated extendible member  87  is pivotally secured to a link pivot connection  94  of the linkage  80  to actuate the displaceable floor-engaging member  86  to firstly cause it to lower and engage a floor surface  95 , as shown in FIG. 11B, and then cause the chair  81  to tilt forwardly, as shown in FIG.  15 C. 
     The linkage of the lifting and tilting mechanism  80  comprises an attaching link arm  96  having a pivot connection  97  and  97 ′ at opposed ends thereof. These pivot connections  97  and  97 ′ are secured to fixed pivot points of the side frames of the chair. The linkage also comprises a pair of right-angled tandem arms  98  and  98 ′ pivotally secured at one end  99  and  99 ′ to a respective one of the pivot posts  93  and  93 ′. The pivot post  93 ′ is disposed at the forward end of the chair, whereas the post  93  is at a rear end thereof. 
     As can be seen more clearly from FIGS. 14A to  14 C, each of the tandem arms is an L-shaped arm and defines an elongated arm section  100  and a transverse right-angled elbow end section  101 . The elbow end sections  101  are pivotally interconnected together at a pivot connection  102  and  102 ′, disposed at a free end thereof, by a longitudinal interconnecting link arm  103 . The forward one of the tandem arms, namely arm  98 ′, has a pivot connection  104  with the forward one  97 ′ of the fixed pivot points of the attaching link arm  96 . This pivot connection  104  is disposed at the intersection  105  of the transverse elbow end section  101  and the straight arm section  100 , as better seen in FIG.  12 . The forward one of the tandem arms, namely arm  98 ′, is pivotally interconnected at the forward end  102 ′ to a rearward one of the fixed pivots, namely pivot  97 , by a set of articulated pulling link arms, namely a long pulling link arm  105  and a shorter pulling link arm  106 , which are interconnected together by a pivot connection  107 . FIGS. 12 and 14A to  14 C illustrate the displacement of these articulated pulling link arms as the extendible member  87  is displaced to its fully extended position. 
     As better illustrated in FIGS. 14C and 11D, the longitudinal interconnecting link arm  103 , the tandem arms  98  and  98 ′, and the floor-engaging member  86  form a rectangular chair support frame that is disposed on the floor surface  95  when the chair is at a full lifted and forwardly tilted position, as shown in FIG.  15 C. This rectangular chair support frame configuration adds rigidity to the entire structure and chair. Also, the extendible member  87  is disposed substantially diagonally across the rectangular chair support frame, forming somewhat a crosspiece whereby to strengthen the frame when in that position. 
     Although not shown, a single motor  90  may be utilized to actuate both the right and left side lifting and tilting mechanisms  80  by having a drive rod extending under the chair and actuated by the gear train provided in the gear box  91 , and coupled to the extendible member  87  on the other side. 
     It is within the ambit of the present invention to provide any obvious modifications of the preferred embodiments described herein, provided such modifications fall within the scope of the appended claims.