CONVERTIBLE TODDLER CHAIR AND STANDING PLATFORM

Abstract

A toddler chair convertible to a standing platform including a foldable support frame with front and rear legs configured to stably support a standing platform and an elevated seat assembly for a toddler. The seat assembly includes a seating portion, a backrest portion, and a moveable elevating frame. The seating assembly is vertically moveable in relation to the support frame. The seating and backrest portions are moveable in relation to each other. A linkage interconnecting the seating portion and the support frame controls movement of the seating portion as the seat assembly is moved in relation to the support frame. In one configuration the seating assembly disposed generally above the platform and is operable as a seat for a child. In a second configuration, the seating portion is repositioned into general alignment with the backrest portion to allow a child to stand on the platform below.

Claims

1. A convertible toddler chair and standing platform comprising: a frame assembly having a front leg and a rear leg, the front and rear legs being pivotally connected and configured to enable movement of the legs about a folding axis between folded and unfolded configurations; a seat assembly disposed above the platform and moveably connected to the frame assembly by an elevating frame, the seat assembly including a seating panel and a pivotally coupled backrest panel; and a seat linkage having a primary link and a secondary link, the seat linkage interconnecting the seating panel and the frame assembly, the seat linkage coordinating movement of the seating panel toward a standing mode with elevating frame movement in a first direction, and coordinating movement of the seating panel toward a seating mode as with elevating frame movement in a second direction opposite to the first direction.

2. The convertible toddler chair and standing platform of claim 1, wherein the front leg includes a first guide and a second guide, wherein the primary link pivotally connects at a first end thereof to the seating panel, the primary link having a slot adjacent to a second end, the slot engaging the first guide, and wherein the secondary link is pivotally coupled at one end to the second guide and pivotally coupled to the primary link at an opposite end.

3. The convertible toddler chair and standing platform of claim 2, wherein the first guide and the second guide are equally radially displaced from the folding axis.

4. The convertible toddler chair of claim 2, wherein the slot interacts with the first guide to limit movement of the seating panel between the seating mode and the standing mode.

5. The convertible toddler chair of claim 1, wherein the seat linkage is configured to restrain the seating panel and elevating frame in the standing mode in an over-center alignment.

6. The convertible toddler chair and standing platform of claim 1, wherein the elevating frame further comprises a telescoping connection with the front leg configured to allow bi-directional movement between raised and lowered positions, the raised position corresponding to the seating panel being positioned in the standing mode.

7. The convertible toddler chair and standing platform of claim 1, further comprising a platform panel pivotally connected to the front leg and moveable between folded and unfolded positions.

8. The convertible toddler chair and standing platform of claim 7, further comprising a platform link interconnecting the platform panel and the rear leg, the platform link operable to move the platform panel between unfolded and folded positions as the legs are moved between folded and unfolded configurations.

9. The convertible toddler chair and standing platform of claim 7, wherein the platform is moveable between the folded and unfolded positions while the seating panel is positioned in either the standing mode or the seating mode.

10. The convertible toddler chair and standing platform of claim 1, further comprising a tray table selectively connectible to the seat assembly.

11. The convertible toddler chair and standing platform of claim 1, wherein the rearward leg further comprises a distally disposed extendable foot moveable between generally opposing retracted and extended positions, the extendable foot when in the extended position increasing the effective length of the rearward leg.

12. The convertible toddler chair and standing platform of claim 10, wherein the extendable foot includes a biasing element configured to bias the extendable foot toward the extended position and allow movement toward the retracted position as the rearward leg is angled as the frame assembly is unfolded and the extendable foot contacts a surface.

13. A convertible toddler chair and standing platform comprising: a foldable frame assembly having a front leg and a rear leg, the legs being pivotally connected and configured for movement about a folding axis between folded and unfolded configurations; a seat assembly moveably connected to the frame assembly, the seat assembly including an elevating frame, a backrest panel and a seating panel rotatably coupled to the backrest panel, the backrest panel connected to the elevating frame for movement therewith and the seating panel rotatable between a seating mode and a standing mode; and a seat linkage having a primary link and a secondary link, the seat linkage interconnecting the seating panel and the frame assembly and coordinating movement of the seating panel toward the standing mode with elevating frame movement in a first direction, and coordinating movement of the seating panel toward a seating mode as with elevating frame movement in a second direction opposite to the first direction.

14. The convertible toddler chair and standing platform of claim 12, wherein the primary link is pivotally connected to the seating panel at a first end of the primary link and includes an elongate slot and an opposite end of the primary link, the elongate guide slot engaging a first guide member disposed on the front leg, wherein the secondary link is pivotally coupled at one end thereof to a second guide member disposed on the front leg and pivotally coupled to the primary link at an opposite end thereof, wherein the guide slot interface with the first guide member limits rotational movement of the seating panel.

15. The convertible toddler chair and standing platform of claim 12, further comprising a standing platform.

16. The convertible toddler chair and standing platform of claim 14, further comprising a platform link coordinating movement of the standing platform with movement of the folding frame assembly between folded and unfolded positions.

17. The convertible toddler chair and standing platform of claim 12, further comprising an extendable foot distally disposed on the rearward leg, the extendable foot moveable between generally opposing retracted and extended positions, the extendable foot when in the extended position increasing the effective length of the rearward leg.

18. The convertible toddler chair and standing platform of claim 17, wherein the extendable foot includes a biasing element configured to bias the extendable foot toward the extended position and allow movement toward the retracted position as the rearward leg is angled as the frame assembly is unfolded and the extendable foot contacts a surface.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0014] The advantages of this invention will be apparent upon consideration of the following detailed disclosure of the invention, especially when taken in conjunction with the accompanying drawings wherein:

[0015] FIG. 1 is a perspective view of a first embodiment of the present invention shown configured in a toddler chair mode and unfolded for use;

[0016] FIG. 2 is a perspective view of the embodiment shown in FIG. 1 shown configured for use in a standing platform mode;

[0017] FIG. 3 is a side elevation view of the embodiment of FIG. 1 shown configured as a toddler seat;

[0018] FIG. 4 is a side elevation view of the embodiment of FIG. 1 configured as standing platform and shown positioned adjacent to a counter-height work surface;

[0019] FIG. 5 is perspective view of the embodiment of FIG. 1 shown in a folded arrangement for storage;

[0020] FIG. 6 is a partial view of a hinge connection between the front and rear legs of the invention;

[0021] FIG. 7 is a partial view of an embodiment of a linkage for repositioning the seat, shown in a first configuration;

[0022] FIG. 8 is a partial view of the linkage shown in FIG. 7, shown in a second configuration;

[0023] FIG. 9 is an alternate view of the repositioning mechanism shown in FIG. 8;

[0024] FIG. 10 is a partial view of the elevating frame in the seat assembly illustrating an embodiment of the elevating frame retention mechanism;

[0025] FIGS. 11A-11E illustrate the movement of the seat assembly between a highchair configuration and a standing platform mode configurations;

[0026] FIG. 12 is a rear perspective elevation view of the toddler seat of FIG. 1 in the unfolded position showing the platform folding linkage;

[0027] FIG. 13 is bottom view of the toddler seat;

[0028] FIGS. 14A-14E illustrate the movement of toddler chair standing platform frame between unfolded and folded configurations;

[0029] FIG. 15 is a view of an embodiment of a toddler chair and standing platform shown in a lowered configuration and having infant seat connected thereto;

[0030] FIG. 16 is a view of the toddler chair and standing platform of FIG. 15 shown in an elevated configuration and having the optional infant seat connected thereto;

[0031] FIG. 17 is a perspective view of an embodiment of a toddler chair and standing platform configured as a standing platform and including a safety rail;

[0032] FIG. 18 is an alternate view of the toddler chair and standing platform with safety rail of FIG. 17;

[0033] FIG. 19 is a side elevation view of a second embodiment of the present invention shown configured in a toddler seat mode;

[0034] FIG. 20 is a side elevation view of the second embodiment of FIG. 19 shown configured in a standing platform mode;

[0035] FIG. 21 is a side elevation view of the second embodiment of FIG. 19 shown in the toddler seat mode and folded position;

[0036] FIG. 22 is a side elevation view of the second embodiment of FIG. 19 shown in the standing platform mode and folded position

[0037] FIGS. 23 through 25 illustrate the embodiment of FIG. 19 as it is moved between the toddler seat mode and the standing platform mode;

[0038] FIGS. 26 through 28 provide a view of an alternate embodiment of the repositioning linkage which repositions the seat as the invention is moved between the toddler seat mode and the standing platform mode;

[0039] FIGS. 29 and 30 show the embodiment of FIG. 19 and the deployment of a safety guard for use in the standing platform mode;

[0040] FIGS. 31 and 32 show an embodiment of the folding joint enabling the frame to move between folded and unfolded positions;

[0041] FIGS. 33 and 34 show an embodiment of a moveable foot enabling the frame to stably stand while in the folded position;

[0042] FIG. 35 shows an embodiment of a linkage coordinating movement of the standing platform with the frame; and

[0043] FIG. 36 shows an embodiment of a tray accessory for use in the toddler seat mode.

[0044] Wherever possible, the same reference numbers will be used throughout the drawings to represent the same parts.

DETAILED DESCRIPTION OF THE INVENTION

[0045] Referring to the figures, a convertible toddler chair and standing platform apparatus 10 is shown with a collapsible frame 15 comprising a front leg 20, a rear leg 30, and a platform panel 40. The front and rear leg are pivotally coupled at their proximal ends by hinge 18 and pivotable about a hinge axis 200 between an unfolded configuration (FIGS. 1-4) and a folded configuration (FIG. 5). When unfolded, feet 25, 35 provided on the distal ends of the front and rear legs support the apparatus 10 on a floor 100 or similar level surface.

[0046] A seat assembly 50 is provided and selectively configurable as a seat to support a toddler occupant (seating mode) or to reposition a portion of the seat to provide clearance for a toddler to stand comfortably on the platform panel 40 (standing mode). The seat assembly 50 includes a seating panel 54 and a backrest panel 56. An elevating frame 51 is moveably connected to frame 15 adjacent to the hinge 18. The elevating frame 51 is selectively positionable in generally opposing lowered (FIG. 1) and raised (FIG. 2) positions which reconfigure the seat into the corresponding seating and standing modes, respectively. The elevating frame 51 may include a downward extending telescoping extension 55 which engages the front leg 20 to facilitate raising and lowering of the elevating frame 51. The elevating frame 51 may also include an armrest 52. Elevating frame 51 may be generally U-shaped in a horizontal plane to extend behind the backrest pane 56 and forwardly on either side as armrests 52.

[0047] A retention mechanism may be provided to hold the elevating frame 51 in at least the raised position until selectively repositioned by a user. The retention mechanism 70 may include moveable pawls 72 positioned inside of the telescoping extension 55 and engageable with the front leg. The pawls 72 may include resilient biasing members to urge the pawls into a locking engagement with the interior portion of the leg. The leg interior may be configured with features to aid in the pawl engagement, such as a rack or spaced-apart recesses or protrusions. A release actuator 74 may be provided and operably connected to selectively disengage the pawls 72 from engagement with the telescoping extension and allow the elevating frame 51 to be moved with respect to the frame 15. The operable connection may include a rod, cable or the like. The release actuator may be located on the elevating frame 51 to allow ease of operation by a user when grasping the armrests 52 or elevating frame 51 to adjust the configuration of the seat assembly 50. The elevating frame may also be restrained in an elevated position by other means, including seating panel linkage, discussed hereinafter.

[0048] Seating panel 54 and backrest panel 56 may be hingedly or pivotally connected allowing rotational movement of the seating panel 54 between a generally horizontal alignment generally parallel to platform 40 below and angled in relation to the backrest panel allowing its use as a seat to support a child (seating configuration, FIG. 1) and a generally upright orientation in which the seating panel surface is rotated downwardly and rearwardly to a position generally aligned with the backrest panel surface which allows a clear space above the platform panel 40 to allow a toddler to stand on the platform panel 40 below for use of the apparatus 10 as a standing platform or learning tower (standing configuration, FIG. 2). In this configuration, the seating panel and backrest panel surfaces form an upright barrier adjacent to the rear of the platform for a child user to lean against while standing on the platform and limits child movement toward the rearward end of the platform. The backrest panel 56 may be connected to the elevating frame 51 for movement therewith. The seating panel 54 may be hingedly or pivotally connected to the backrest panel 56 and may move about seatback hinge axis 210. The seating and backrest panels 54, 56 may be configured to limit the extent of downward rotational movement of the seating panel 54. Movement of the seating panel 54 is affected by raising and lowering the elevating frame 51 and attached backrest panel 56. Movement of the seating panel 54 may also be affected by user movement of the seating panel directly.

[0049] A seat linkage 60 interconnecting the foldable frame 15 and the seating panel 54 may be provided and configured to coordinate seating panel 54 movement with movement of the elevating frame 51 between elevated and lowered positions. One embodiment of seat linkage 60 may include an elongate link member 65 pivotally connected at a first pivot point 67 to the frame 15 and at a second pivot point 68 the seating panel 54. The seat link 60 may include separate link members 65 disposed on opposite sides of the seating panel 54 so that the respective first and second pivot points 67, 68 define first and second pivot axes 220, 230. The link members 65 and location of the first and second pivot points 67, 68 may be configured to coordinate rotation of the seating portion 54 about hinge axis 210 as the back panel 56 is raised and lower by movement of the elevating frame 51. The spatial relationship of the first and second end 67, 68 pivot points may be configured to position the link member 65 in an over-center configuration to maintain the elevating frame 51 in the elevated position either in lieu of or in combination with retention mechanism 70. As best illustrated in FIGS. 11C through 11E, the over-center seat link configuration requires elevating the elevating frame 51 slightly from the elevated position to allow the link to rotate slightly so that when downward movement of the elevating frame 51 commences, the seat link may rotate fully to move the seating panel toward the seating position.

[0050] An alternative embodiment of the seat linkage 600 is illustrated in FIGS. 23 through 28. The linkage 600 includes a primary link member 651 and a secondary link member 652. Primary link member 651 is pivotally connected to the second pivot point 68 on seating panel 54 at a pivot connection 681. An elongate guide slot 654 is provided in the primary link member generally opposite of the pivot connection 681. The guide slot engages a guide member 671 affixed on the front leg 20 of the foldable frame 15. The guide slot 654 is configured to allow the guide member 671 to move in the slot corresponding to movement of the seating panel 54 between toddler seat mode (FIGS. 23 & 26) and standing platform mode (FIGS. 25 & 28).

[0051] The guide slot 654 may be configured to limit the range or rotational motion of the seating panel 54. The guide slot 654 configuration and may permit additional vertical movement of the elevating frame 51 to an acme in the second direction and allow the seating panel 54 to rotate toward the standing position, continued rotation of the seating panel aligning the seat linkage over-center, accompanied by a slight movement of the elevating frame toward the first position. The alignment of the first and second links is such that the linkage locks the seating panel in the standing position. The weight of the elevating frame 51 and backrest panel 56 holds position in an over-center alignment of the seat linkage 600. Reconfiguring the seating panel requires lifting the elevating frame slightly toward the second position while initiating rotating of the seating panel 54 toward the horizontal seating position which releases the over-center linkage alignment and allows continued movement of the seating panel 54 as it is moved to the seating configuration and the elevating frame moves toward the first position. Primary link member 651 may be curved to improve fluidity of motion as the seating panel is moved.

[0052] Secondary link member 652 includes pivoting connections at opposing ends, a first connection 655 pivotally connected to the front leg 20 of the foldable frame 15 and a second connection 656 pivotally connected to first link member 651. The location of second connection 656 is proximate to pivot connection 681 and configured to coordinate with the primary link member 651 to rotate the seating panel 54 with vertical movement of the elevating frame 51. The pivoting connections of secondary link member 652 in combination with the positioning of primary link member so that an end 657 of the guide slot 654 abuts the guide member 671 to stabilize support for the seating panel 54 when the seating panel is in the horizontal, seating configuration.

[0053] In the standing platform mode, the seat assembly, including the elevating frame 51, the seating panel 54 and the backrest panel 56, may be configured to create a guide barrier generally along three peripheral sides of the platform panel 40 and at a location above the platform panel surface to provide a handhold for stability of a child user of the standing platform. The telescoping motion of the elevating frame 51, preferably aligned with the angled orientation of the front leg 20, causes the backrest portion 56 which may be fixed to the elevating frame 51 to move upwardly and slightly rearwardly. In an embodiment best illustrated in FIG. 4, this rearward motion shifts the guide barrier formed by the backrest and seating panels rearward in relation to the frame thereby allowing the entire standing platform apparatus to be more closely located adjacent to a cabinet face 105 and offer better access for the child user to the countertop work surface 110.

[0054] In an embodiment, platform panel 40 may be pivotally connected directly to the front leg 20 at a front pivot 41 for rotation about a first platform axis 240 and indirectly through a pivotally coupled platform support link 42, the interlink causing rotation of the platform panel 40 as the legs are moved between the folded and unfolded configurations. The support link 42 is connected to the rear leg at a leg pivot 31 (pivot axis 250) and to the platform panel 40 at a platform pivot 43 (pivot axis 260). A stop 32 may be provided on the rear leg to engage the support link 42 and limit the degree of support link rotation as the legs rear 30 are moved toward the unfolded configuration. This limitation establishes the extent of the leg unfolding movement and maximum space between the distal ends of the front and rear legs.

[0055] Leg and platform movement in an embodiment as the frame is moved from the unfolded to the folded position is illustrated in FIGS. 14A-14E. The collapsible frame 15 may be moved between folded and unfolded positions while the seat assembly is in either the toddler seating mode or standing platform mode configurations.

[0056] Platform panel 40 weight and angle of the support link 42 in relation to its pivot connection 31 to rear leg 30 when unfolded is slightly over-center so that weight of the platform holds the chair legs 20, 30 in the unfolded configuration and the support link 42 in adjacent contact with the stop 32. The over-center locking alignment biases the unfolded support legs toward the unfolded configuration thereby minimizing stresses on any latching mechanism that may be provided to retain the support legs in the unfolded configuration. Folding the frame requires first lifting the platform panel 40 slightly to begin moving the support link (rotating the link counterclockwise as illustrated in FIG. 14A) to then allow the rearward end 48 of the platform panel 42 to begin moving downwardly and allow the frame to be completely folded.

[0057] In the folded position of collapsible frame 15 the distal ends of the front and rear legs 20, 30 are brought closely adjacent to reduce the space required for storage. Pivoting movement of the platform 40 moves its rearward end 48 downwardly proximate to the distal ends of the front and rear legs 20, 30. The platform panel may be further configured so that when in the folded orientation, the rearward end 48 may contact the floor surface and, in concert with the front leg foot 25, allow the folded apparatus to stand generally upright on a floor surface.

[0058] The pivoting axes including hinge axis 200, first and second axes 220, 230 for the seat linkage and platform pivot axes 240, 250, 260 are all transversely arranged to the folding frame and parallel to one another. The second pivot axis 230 may or may not align with the hinge axis 200 of the folding frame. In the exemplar embodiment, second axis 230 and hinge axis 200 are non-coaxial.

[0059] An alternative embodiment of standing platform 40 and its folding arrangement is illustrated in FIGS. 33-35. In this arrangement, the platform panel 40 folds upwardly (rearward end moves up) as the toddler chair and standing platform apparatus 10 is moved toward the folded configuration and is thus not positioned to stably support the folded frame. The platform 40 is pivotally connected to the front legs at front pivot 41 which allows platform rotation about first platform axis 240. Alternate platform link 44 (FIG. 35) interconnects the standing platform 40 and the rearward leg 30 and coordinates movement of the standing platform with folding movement of the frame.

[0060] In order to allow the folded frame to stand stably when folded, an extendable foot 37 is provided on the distal end 35 of each rearward leg 30. The extendable foot 37 is moveable between generally opposing retracted (FIG. 33) and extended positions (FIG. 34) and may be pivotally connected to the leg at pivot 39. A housing 36 may be provided to receive the extendable foot 37 when it is in the retracted position and allow the distal end 35 of the rearward leg to support the frame on a floor or supporting surface. A biasing element 38 may be provided to bias the extendable foot into the extendable foot 37 toward the extended position. The biasing element 38 may be a compression spring, torsion spring, or other known resilient member capable of producing a biasing force on the extendable foot. One or more travel stops may be provided to limit extendable foot movement toward at least the extended position. When the frame 15 is folded closed and lifted from the supporting surface, the extendable foot 37 rotates to extend downwardly of the rearward leg, extending the effective length of the rearward leg 20 to allow the frame to stably stand while the frame is in the folded configuration. When the frame 15 is opened and positioned for use, the extendable foot 37 contacts the floor or supporting surface at an angle causing it to rotate against the spring bias toward the retracted position. The rotational movement positions the extendable foot 37 within the housing 36 and at least so that the distal end 35 of the rearward leg contacts the floor without interference by the extendable foot. The spring biasing force is selected to be sufficiently low so the weight of the chair easily overcomes the spring biasing force and allows the foot to rotate toward the retracted position.

[0061] FIGS. 31 and 32 illustrate an embodiment of the folding hinge 18 which includes travel limiting features. Pivot guides 671, 672 are secured to the front leg 20 of the folding frame 15 and extend inwardly in a direction parallel to the frame folding axis 220 (see FIGS. 6 through 8). A housing 34 may be provided on the rearward leg 30 at the folding hinge 18. The housing 34 may include travel slots 342, 344 which are arcuately arranged about the folding axis 220. The pivot guide 671, 672 extend away from their connection to the front leg a distance sufficient to project through the travel slots 342, 344. The interface pivot guides and travel slots interface to limit the pivoting movement or the rearward leg 30 in relation to the front leg 20. Pivot connection 655 may be integrated with pivot guide 672.

[0062] Referring to FIGS. 15 and 16, an optional infant seat 80 is shown attached to the toddler chair and standing platform apparatus 10. The infant seat 80 increases the utility of the toddler chair by providing seating configured for a younger, smaller occupant. The infant seat may be selectively attached to the armrest 52 so that it is moveable between elevated and lowered positions with movement of elevating frame 51.

[0063] The seat assembly 50 may also or alternatively include provisions to secure a child occupant in the seat when the apparatus 10 is configured as a toddler seat without a separate infant seat, best illustrated in FIG. 35. The provisions may include a restraint harness 100, such as lap and/or shoulder belts. The seat assembly 50 may include accessories to allow use as a highchair. The accessory may include a tray table 110. The tray table 110 may include additional features to restrain a child occupant in the seat, such as an anti-submarine horn 112 or the like, to be used in combination with any installed restraint harness.

[0064] Referring to FIGS. 17 and 18, an embodiment of the toddler chair and standing platform apparatus 10 is shown configured as a standing platform. An optional safety rail 90 is shown and may extend from the armrest 52 of elevating frame 51, connecting the respective armrests on either side of the apparatus 10 to create a barrier to movement by a toddler standing on the platform. In one embodiment, safety rail 90 comprises a ribbon 92 that is flexible in one plane (horizontal) allowing it to bend and create a semi-circular loop at the forward end of the apparatus while being generally rigid in a perpendicular plane (vertical) so that it remains generally co-planar with the armrests 52 from which is extends. The safety rail may include a retracting mechanism disposed in one armrest allowing the ribbon to be selectively extended therefrom and curved to the opposite armrest where it may be selectively secured by any suitable means such as a catch or receptacle. The safety rail 90 may include a rigid member that is selectively attachable to the armrests 52 for use and removeable when not in use. An alternative embodiment of the safety rail 90 is illustrated in FIGS. 29 and 30 comprising a flexible portion 94 and a rigid portion 95 extensible from one or both of the arm rests 52. A connector 95 may be provided at an end of the rigid portion to allow connection to either a second rigid portion extending from the opposite arm rest or directly to the opposite arm rest.

[0065] While the exemplary embodiments illustrated in the figures and described herein are presently preferred, it should be understood that these embodiments are offered by way of example only. Accordingly, the present application is not limited to a particular embodiment, but extends to various modifications that nevertheless fall within the scope of the appended claims. The order or sequence of any processes or method steps may be varied or re-sequenced according to alternative embodiments.

[0066] It is important to note that the construction and arrangement of the various exemplary embodiments is illustrative only. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited in the claims. For example, elements shown as integrally formed may be constructed of multiple parts or elements, the position of elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. Accordingly, all such modifications are intended to be included within the scope of the present application. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. In the claims, any means-plus-function clause is intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present application.