REVERSE FOLD TIER CATCHES FOR STADIUM SEATING

Abstract

A tier locking assembly for allowing highest-to-lowest tier retract in a telescopic seating assembly that includes a plurality of seating tiers with seating platforms supported by movable supports structures that move relative to one another along a first direction. The tier locking system has a tier catch attached to a lower tier that automatically engages a catch plate of an adjacent higher tier to prevent that higher tier from retracting over the lower tier.

Description

TECHNICAL FIELD

The present invention relates generally to telescoping stadium seating structures, and more particularly to tier catches for releasably locking telescoping seating platform sections.

BACKGROUND INFORMATION

Conventional telescopic seating assemblies are comprised of individual seating “tiers” coupled together and configured to be pulled from a stowed, telescoped position (usually against a wall) to a fully extended position for use as a stepped spectator structure. See generally FIG. 1.

In such structures, individual tiers typically include a seating platform supported by a pair of spaced support structures. Each support structure includes a floor-engaging base assembly (often call a casterhorn by those skilled in the art) fitted with wheels or rollers on which the tiers are rolled between the stowed and use positions, a support column extending vertically upwards from the base assembly, and a cantilever beam extending forward from the support column.

Each seating platform typically includes a nose beam attached at the ends of respective cantilever beams, decking attached to a top surface of the cantilever beams, and a rear riser beam extending above the decking adjacent the support columns. Seating structures are generally included near the nose of each platform section, and, when the tier is in a stowed position, can either be stowed beneath the next higher tier or can be stowed against the nose of the next higher tier as shown in FIG. 2.

Conventional telescopic seating assemblies are generally retractable in the order of shortest tier to highest tier. That is, from an extended seating configuration, the lowest and farthest forward tier is first nested beneath the next higher tier. As a lower tier retracts against a higher adjacent tier, both tiers then retract under the next-higher adjacent tier, and so on until all movable tiers are retracted in a substantially vertical stack.

Each tier is slidingly engaged with adjacent tiers to allow the tiers to remain aligned while its position is changed. Once extended to a use position, (FIG. 2A) each extended tier is locked against relative movement with an adjacent tier. One solution providing this locking action is a tier catch assembly that prevents intermediate tiers (that is, tiers in the middle of the seating assembly that are not yet nested) from prematurely retracting towards adjacent tiers. In addition to creating an unwanted or disorderly nesting progression, freely moving tiers can wrack or “twist” the seating assembly if one side of the seating assembly retracts at a different rate than the other side, skewing the structure and binding adjacent support structures against one another.

A typical tier catch assembly includes a mechanism that successively disengages the catch assembly of the next-highest tier only when the lower tier is fully nested thereunder. Such a system is described in US Patent No. 6,539,672, which is incorporated herein by reference.

This shortest-to-highest retracting (or “folding”) is typically accomplished by moving the lowest tier rearward towards the higher tiers, and once nested under the next-higher tier, both the lowest and next highest tier are moved together against the yet-next-higher tier, and so on until all tiers are stacked against the highest and rear-most tier (See FIGS. 2A-2D).

While the lowest tier is typically moved rearward towards the higher tiers, there are situations that call for access to floor space beneath the rearmost tiers, such as for cleaning, or to provide a “walled-off” open area behind the stacked tiers to provide a separated space for events, storage, or other uses. In these instances, the tiers can alternatively be moved from the highest rear-most tier forward towards the lowest tier. However, with the typical catch assemblies engaged as described above, the tiers would still retract with the lowest tier nesting first under the next-higher tier, as the catches are only disengaged when the next-lower tier is fully beneath the next higher tier (See FIGS. 3A-3D). That is, all of the higher tiers must be moved in their extended states toward the lowest tier so that the lowest tier can disengage the next-higher tier's catch assembly, allowing that next-higher tier to move under its next-higher tier and disengage that next tier's catch assembly. This situation effectively renders the entire seating assembly unusable after multiple tiers are retracted, as users are unable to use the stowed seating of the lowest tiers, and are unable to access the seating the higher tiers. Additionally, as more tiers are pushed to their retracted positions, the tier catches used therewith become heavily loaded and difficult to release.

Therefore, there is a need for tier catch assembly that allows a seating assembly to be folded in reverse, that is, for the higher tiers to retract or fold over the next-lower tiers, with the catch assembly of the next-lower tier disengaging when the higher tier is retracted thereagainst, to allow the lowest tiers to be accessed and utilized even if a portion of the seating assembly is retracted.

SUMMARY OF THE INVENTION

The invention described herein is a reverse-fold tier catch assembly used to releasably lock adjacent seating platform sections together when in an extended orientation. The catch assembly is designed to be self-engaging in that the need for a trip bar to initiate initial telescopic seating retraction is eliminated. The locking mechanism is comprised primarily of a tier catch mounted on the outer side of a casterhorn. The tier catch has an extended cam follower for engaging a cam surface of a lifting arm sliding there past.

The present features a tier locking system for allowing highest-to-lowest tier retraction in a telescopic seating assembly that includes a plurality of seating tiers with seating platforms supported by movable supports structures that move relative to one another along a first direction.

The tier locking system comprises a first tier catch having a substantially vertical tier catch body, a strike plate and a pivot tab extending from one side of the first substantially vertical tier catch body, as well as a cam follower extending from an opposite side of the tier catch body, wherein the tier catch is pivotally attached to a first support structure.

The invention also features a first catch plate having a substantially vertical body attached to a second support structure and a substantially horizontal lock arm extending over the first support structure in the path of the strike plate of the first tier catch on the first support structure in the first direction.

A second catch plate having a substantially vertical body is attached to a third support structure, along with a substantially horizontal lock arm extending over the second support structure, and a cam arm extending from the lock arm in the path of the cam follower of the first tier catch in the first direction.

Wherein the interaction of the cam arm and the cam follower caused by movement of the first support structure relative to the second support structure in a horizontal direction acts to pivot the tier catch about its pivot axis.

The summary here is not an exhaustive listing of the novel features described herein and are not limiting of the claims. These and other features are described in greater detail below in view of the drawings appended hereto.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of a telescopic seating assembly according to an embodiment of the invention;

FIG. 2A-2D are side elevational views of a lowest-to-highest telescopic seating system in successive stages of retract in accordance with the prior art;

FIG. 3A-3D are side elevational views of a highest-to-lowest telescopic seating system in successive stages of retract in accordance with an embodiment of the invention;

FIG. 4 is an isometric view of adjacent support structures in a partially-retracted configuration according to an embodiment of the present invention;

FIG. 5 is a close-up isometric view of the lowest tier support structures of an embodiment of the invention;

FIG. 6 is a front elevation view of the embodiment of FIG. 4;

FIG. 7 is a semi-exploded isometric view of a support structure according to an embodiment of the invention;

FIGS. 8A-8E are isometric views of different level tier support structures according to an embodiment of the invention;

FIG. 9 is an isometric view of a tier catch according to an embodiment of the invention;

FIG. 10A is an isometric view of a first latch plate according to an embodiment of the invention;

FIG. 10B is an isometric view of a second latch plate according to an embodiment of the invention;

FIGS. 11A-11B are side elevation views of the main elements of a catch assembly in various positions according to an embodiment of the invention;

FIGS. 12A-12F are side elevation views of the catch assemblies in various stages of disengagement according to an embodiment of the invention.

FIGS. 13A-13F are side elevation views of just the tier catches and hooked lock plates of FIGS. 10A-10F isolated for clarity;

FIG. 14 is an isometric view of adjacent support structures in a fully extended configuration according to an embodiment of the invention; and

FIG. 15 is a side elevation view of a support structure having a drive unit according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EXAMPLES

Exemplary embodiments will be described in detail herein and examples of the exemplary embodiments are illustrated in the accompanying drawings. Unless specified otherwise, the same numbers in different accompanying drawings represent the same or similar elements when the accompanying drawings are described hereinafter. The implementation modes described in the following exemplary embodiments do not represent all the implementation modes consistent with the present invention and disclosure as would be understood by those skilled in the art. In contrast, they are only examples of exemplary devices and consistent with the present disclosure.

Referring to FIG. 1, a telescopic seating system 1 is shown comprising a plurality of individual seating tiers 12 in their fully extended, stepped seating arrangement. Each tier 12a-12e includes a seating platform 14 supported by a pair of spaced support structures 16 at each end. A support structure 16 on one end of the seating platform 14 is a mirror of the support structure 16 at the other end of the seating platform 14.

For purposes of establishing directional descriptors to be used herein with respect to elements of the seating assembly, the following terms shall be defined as such: “front” means the area adjacent the lowest seating tier, and “forward” means in a direction towards the “front”; “rear” means the area adjacent the highest seating tier, and “rearward” means in a direction towards the “rear”; “top” means a surface farthest away from the floor on which the seating assembly is located, and “upward” means in a direction away from the floor; “inside” and “inner” refer to an area or surface that is between the two support structures of an applicable tier; “outside” and “outer” refer to an area or surface that is on an opposite side of an applicable support structure as the “inside” or “inner” areas or surfaces of an applicable tier.

Further, elements may be labeled herein generically as an unmodified element number (such as “a tier 12”) or modified with a character to identify elements of a specific tier when such designation is helpful in describing relational features (such as “lowest tier 12a”).

Each support structure 16 has a floor-engaging base member (often terms a “casterhorn”) 162, a support column 164 extending upward from a rear portion of the base member 162, and a cantilever beam 166 extending forward from the support column 164 substantially parallel to the base member 162. The height of the columns establish the height of the tiers and carry the loads placed on the platforms.

Each seating platform 14 includes a nose beam 146, or nose, attached at the distal ends of cantilever beams 166. Decking 142 is attached to a top surface of the cantilever beams 166. In some embodiments, a rear riser beam 144 extends vertically to both act as the main load carrying member of the structure and close the gap between the decking 142 of its tier and the nose beam 146 of an adjacent higher tier when the lower tier is in an extended position relative to the higher tier.

In some embodiments, seating 148 may be provided adjacent the nose of each seating platform 14, leaving a space between the seating and rear riser beam to serve as an aisle-accessway for seating occupants to walk along to get to a seated spectating location. In some examples, seating 148 can be in the form of a bench such as that shown in FIG. 1, which is sized to slide under the nose beam 146 of a next higher tier when the lower tier is in retracted stored position.

Alternatively, seating 148 can be chairs (not shown but known in the art) that are stowed vertically against the front of a higher tier when the tiers are retracted or can fold flat along the decking and slide under the next higher tier when retracted.

When tiers are in their extended positions, preventing relative movement therebetween acts both to provide a more controlled retracting sequence as well as increasing the stability and safety of the seating system. As discussed earlier, previous methods of preventing such relative movement focused on releasing a locking mechanism that was preventing relative movement between tiers, and would allow a controlled retraction of a seating assembly between the lowest tier 24, FIG. 2, and the next higher of the un-retracted intermediated tiers 22. Once the locking mechanism is released, a compressive force, whether applied from the front to move the lowest tier 24 under the next higher tier, or from the back to the move all higher tiers 22/28 over the lowest tier 24, initiates the retract of the seating system as shown in FIG. 2B. Additional compressive force then puts the two lowest tiers in stack 25 under the next higher tier 22 as in FIG. 2C, and again with that retracted stack of tiers 25 under the next higher tier 22 as shown in FIG. 2D.

A major drawback of a “lowest first” retracting system such as that shown in FIGS. 2A-2D is that the lowest, and typically most accessible from the floor level, tier, which is also closest to a spectator event in front of the seating assembly, is rendered unusable by virtue of its stowed and nested position. Furthermore, access to higher tiers may be blocked by virtue of the lowest tier being inaccessible.

A “highest first” retracting system, following the sequence shown in FIGS. 3A-3D allows the footprint of seating assembly 30 to be reduced while maintaining the lowest tier 34 and all adjacent and non-retracted tiers in a usable extended position, and also preserving access to higher tiers 32 that have not been retracted. Highest tier 38 and the next lowest of intermediate tiers 32 will be the first to retract into a nested arrangement as shown in FIG. 3B. Once nested together into stack 36, movement of the lower tiers 32 toward stack 36 will disengage the next tier catch and allow the seating assembly 30 to retract further as shown in FIG. 3C, and then similarly once again as shown in FIG. 3D.

FIG. 4 shows movable support structures 16a-16e in a partially-retracted configuration. Support structures 16a-16e are nested within one another with each support structure becoming more narrow in overall width as you move from structure 16e to 16d to 16c etc, to 16a. Support structures 16e and 16d are retracted against the stop plate 70c of support structure 16c. The tier catch 60b of adjacent support structure 16b has been lifted by the catch plate 50d of support structure 16d, freeing catch plate 50c of support structure 16c to move forward unobstructed by tier catch 60b. Support structure 16b is locked against retracting to a nested state by a locking system comprised of catch plate 47b of support structure 16b interlocked with tier catch 60a of support structure 16a.

In some examples, the highest and rearmost support structure 16e is not interlocked with the next lowest support structure 16d, which allows for initiation of a retract procedure without having to first unlock, or disengage, the rear support structure 16e either manually or through some other external initiator. In some examples, the highest support structure 16e is locked to the adjacent tier, in which case it must be unlocked before initiating a retract procedure.

In some example embodiments, the lowest tier 12a is fixed in place relative to the floor using securing plates 45 (as shown in FIG. 5). Securing plates 45 can utilize typical mechanical fasteners such as bolts or hooks or can include electro-mechanical fasteners such as electromagnets to secure the front tier to the floor, increasing stability of the seating structure during use, as well as resisting the compression force from rearward tiers during a retracting procedure when higher tiers are pushed towards the lower tiers.

FIG. 6 shows a close-up front view of the assembly of FIG. 4, illustrating the relative sizes and clearances between adjacent tiers, as well as details of base members 162 such as an exemplary tier locking assembly having tier catches 60 and catch plates 47/50 as described in more detail below. Stop plates 70b-70e have been removed in the view of FIG. 6 to allow for better visibility.

The full height of support structure 16a of the lowest tier 12a is shown in FIG. 6 supporting an end of seating platform 14a with column 164a and cantilever 166a (shown in ghost). The outermost portions of nose 146 and seating 148 (as well as rear riser 144 not shown) are situated on the tier 12a to be within the opening within the next larger tier 12b. The confines of the next higher tier's 12b opening are substantially defined by the lower edge of seating platform 14b and the inner edges of support structure 16b, including the inner surfaces of column 164b. So, to generalize, each lower tier fits within the next adjacent higher tier, which is both wider and higher than substantially all of the lower tier (with the exception of tier catches 60, stop plates 70, and catch plates 47/50).

Tier catches 60 are located in front of the base of their associated column 164 and stop plate 70a of tier 12a prevents the next higher tier, including the column that appears to be in the path of the lower tier catch, from sliding past the lower tier. Tier catch 60c in FIG. 14 shows another example of this relationship with the column 164d of next-higher tier support structure 16d.

FIG. 6 also illustrates the interaction of a tier catch 60 of a lower tier with the catch plates 47/50 of an adjacent higher tier. For example, catch plate 47b is mounted on an inner surface of base assembly housing 40b of support structure 16b, and extends over the upper surface 426 of the base assembly 162a of support structure 16a. Because, as seen in FIG. 4, support structure 16b is in an extended state with regards to support structure 16a, tier catch 60a is engaged with the catch plate 47b to prevent support structure 16b from sliding into a retracted position.

Support structure 16c is in a position just before moving forward along locked support structure 16b, as next-higher support structure 16d is contacting stop plate 17c and will begin pushing thereagainst to move support structure 16c forward. This is possible because catch plate 50d has lifted tier catch 60b with cam arm 59 (see FIG. 10B), unlocking the catch plate 50c from the tier catch 60b.

Support structure 16d as shown in FIGS. 4 and 6 has been moved forward after catch plate 50e disengaged tier catch 60c from catch plate 50d.

FIG. 7 shows a semi-exploded view of an example support structure 16. Support structure 16 has a base member 162 having a base member housing 40 comprising a channel body 42 defining a channel that houses one or more wheels 44 therein. Base member 162 further includes locking system elements attached thereto, including tier catch 60 that is pivotally mounted to the outside surface of channel body 42 via fasteners 68 extending through an aperture 424 in the channel body and an aperture in the tier catch 60, and catch plate 50 that is rigidly attached to an inside surface of channel body 42 via fasteners 58 extending through apertures 422 of channel housing 42. Stop plate 70 is rigidly attached to the front of channel body 42 and extends outward to be in the path of an adjacent higher support structure.

Support column 164 extends upward from a back end of base member 162 to define the height of and to transfer the load of a seating platform attached thereto. A cantilever 166 extends forward from the top end of column 164. Attachment plates 1644 and 1646 provide mounting points for a seating platform attached to the support structure 16. Tier catch 60 includes elements that extend inward to be over the base housing 40 in order to define limits of rotation. Specifically, as seen in FIG. 9, tier catch 60 includes a strike plate 65 that defines a lowest position when the strike plate 65 is in contact with an upper surface 426 of channel body 42. Tier catch 60 also includes a pivot tab 68 that defines a highest position when the pivot tab 68 contacts an inner surface 1644 of column 164.

FIGS. 8A-8E show support structures 16a-16e, respectively, to clearly show the configuration of locking system elements of each support structure to allow the extension and retraction of the seating assembly. In general, any higher tier that moves over a lower tier includes a catch plate 47/50 on an associated base member 162 that can be locked in place by a tier catch 60 when the higher tier is in an extended position with respect to an adjacent lower tier. The process of locking and unlocking adjacent tiers to one another is done automatically as described more fully below. Also in general, lower tiers prevent motion of an adjacent higher tier therepast with an associated tier catch 60 on its base member 162.

An exception may arise when the highest tier is locked in place in its extended position by some other means to allow for easier initiation of a retracting procedure. However, a tier catch can be lifted manually by pulling up on the pivot tab 68 of a tier catch 60 and pushing the highest tier forward until the catch plate 50 thereof is beyond a locking area. Once able to move, movement of the highest tier against lower tiers will automatically disengage tier catches 60 as the cam arms 59 of catch plates 50 slide past.

Referring again to FIGS. 8A-8E, each of support structures 16b, 16c, 16d and 16e is movable with respect to a lower support structure, and as such each has a catch plate 47/50. In the shown example embodiment, each support structure 16a, 16b and 16c have tier catches 60a, 60b, and 60c, respectively, to prevent higher support structures from moving thereover. Support structure 16d in this example does not rely on a tier catch 60 to prevent the support structure 16e from moving (as described above), and therefore does not include a tier catch 60. Alternatively, support structure 16d may utilize a tier catch 60d (not shown) to prevent movement of support structure 16e thereover if tier catch 60d is disengaged by some external means.

Each of the support structures 16a-16e also includes a respective stop plate 70 attached at a front end thereof. In some examples, stop plates 70 are configured to provide a pushing surface on a front side thereof that contacts an abutment surface on the rear side of the stop plate 70 of an adjacent lower support structure to transfer a force thereto. In some examples, the front surface of stop plate 70 does not extend beyond the front end of the base housing 40 to which it is attached. In that case the rearmost highest tier does not need to include a stop plate 70 because it would neither transfer or receive a force to or from an adjacent support structure.

FIG. 9 shows a detailed view of a tier catch 60 to further illustrate its features. Tier catch 60 is comprised of a substantially vertically orientated tier catch body 62 through which a pivot aperture 64 is defined. A cam follower 66 extends horizontally from the tier catch body 62 into the path of an adjacent higher support structure. Cam follower 66 is shaped to ride along a cam surface 592 of a catch plate 50FIG. 10B of an adjacent tier to raise and lower a front end of the tier catch 60. A strike plate 65 extends inwardly from the tier catch body 62 and includes a rear edge 653 that, when the tier catch 60 is in its lowest position as described above, rests on the top surface 426 of the base housing to which the tier catch 60 is attached.

When the tier catch is in its lowest position, the strike plate is angled upwards such that the forward edge 651 thereof FIG. 11A extends higher than the top surface 474/54 of an adjacent catch plate 47/50. This allows for a bottom surface 652 of strike plate 65 to contact and slide upwards against the adjacent catch plate 47/50 when its support structure is being moved to an extended position (see FIG. 13E for relative positioning, but with movement of catch plate 50 in a direction opposite to arrow A).

Pivot tab 68 also extends inward and is configured to contact a front surface 1644 of the column 164 to which it is connected. This prevents the tier catch 60 from rotating to a position where its center of mass is above or behind the pivot point 64, so that the tier catch is always gravitationally biased towards its lowest position.

Tier catch body 62 includes a latch formation 690 that defines a capture area between the latch formation and the top surface 426 of the connected base housing 40 when the tier catch 60 is in its lowest position. A catch plate 47/50 is substantially locked in place when disposed within the capture area of a tier catch 60. The capture area of latch formation 690 is comprised of three main surfaces: a clearance surface 691, a rear abutment surface 692, and a forward abutment surface 693. The clearance surface 691 is configured to define the top of the capture area remain above and not interfere with the lock arm 474/54 of a catch plate 47/50 disposed within the capture area. Rear abutment surface 692 is situated at the back of the capture area adjacent a front surface 1644 of its connected column 164. In some examples, rear abutment surface 692 is rearward of the column front surface 1644 such that a rear edge 478/58 of catch plate 47/50 within the capture area contacts the column surface 1644 when the support structure 16 of the associated catch plate 47/50 is in a “most-extended” position (as shown in FIG. 11A). In that case, the column front surface 1644 defines a rearward limit of the capture area.

In some examples, rear abutment surface is forward of the column surface 1644, and a catch plate 47/50 within the capture area contacts the rear abutment surface 692 when the support structure 16 of the associated catch plate 47/50 is in a “most-extended” position.

Forward abutment surface 693 defines a forwardmost limit of the capture area and limits the movement in the forward retracting direction of a catch plate 47/50 captured therein. In some examples forward abutment surface 693 is disposed at an angle parallel to an axis 11x such that when a forward edge 476/56 of a catch plate 47/50 contacts and pushes against the forward abutment surface 693 (see FIG. 11B), the major component of the pressing force is normal to the forward abutment surface 693. In some examples, the angle of axis 11x is chosen such that the normal force at the point of contact of an abutting catch plate 47/50 lies along an axis 11y that goes through the pivot point 64 to provide a stronger and more reliable latching action of the tier catch 60.

Catch plates 47 and 50 are shown in FIGS. 10A and 10B, respectively. Each catch plate 47/50 includes a vertical mounting body 472/52 that is fixed to an inner-facing surface of base housing 40. A catch plates 47/50 is fixed such that its lock arm 474 extends over the base housing 40 of an adjacent lower support structure at a height that rides above the upper surface 426 of the adjacent base housing 40 but is lower than the front edge 651 of the strike plate 65 of an adjacent tier catch 60.

Tier catches 47 and 50 are substantially alike except for the addition of a cam arm 59 attached to the lock arm 54 of catch plate 50. As shown in FIG. 10B, cam arm 59 includes a forward cam surface 592, a peak 596, and a trailing cam surface 598. FIGS. 12A-12F and 13A-13F illustrate the interaction of a tier catch 60 with the cam arm 59 of catch plate 50.

FIGS. 12A/13A show a first position where tier catch 60a connected to base member 162a has catch plate 47b of base member 162b locked within the capture area of its hook formation 690. Catch plate 50c attached to the front of base member 162c is moving forward (in a seating assembly extended or deployed position) in the direction indicated by arrow F.

In the position of FIGS. 12B/13B, base member 162c has moved further forward such that cam follower 66 of tier catch 60a has contacted and moved upward along the forward cam surface 582, lifting the strike plate 65 off base housing upper surface 426. At this position base member 162c has not yet contacted the stop plate 70b of base member 162b.

FIGS. 12C/13C show the point at which base member 162c has made contact with stop plate 70b of base member 162b, and cam follower 66 has reached the peak 596 of cam arm 59. As base member 162c continues forward, now along with base member 162b and catch plate 47, cam follower 66 has slid down the trailing cam surface 598 to a position where a slide point 694 of the hook portion 690 of the tier catch 60 has contacted the top surface of the lock arm 475. In some example implementations of the invention, slide point 694 is configured to remain off the top surface 426 of base housing 40 when tier catch 60 is in its lowest position where rear edge 653 of strike plate 65 is resting on the housing surface 426 (as described above). However, when the tier catch 60a is rotated to the position of FIGS. 12D/13D where slide point 694 is riding along the catch arm 475, the rear edge 653 of strike plate 65 is at the same (or higher) height of the contact area of slide point 694 and lock arm 475. This allows the rear edge 653 of strike plate 65 to clear the front edge 476 of catch plate 47b as catch plate 47b moves past strike plate 65.

In the position of FIGS. 12E/13E, the strike plate 65 of tier catch 60a is sliding off the back edge 478 of the lock arm 475, and comes to rest on the housing top surface 426 as base members 162b and 162c continue forward. When the base members are moving in the opposite direction of F during an extending procedure, the steps shown in FIGS. 12A/13A-12F/13F occur in the reverse order to re-engage the catch plates 47/50 within tier catches 60.

FIGS. 14 and 15 show an example arrangement of support structures having substantially the same front structures 16a-16e with their typical base members 162a-162e, but adds a powered base member 150 that acts to both prevent motion of the rearmost highest support structure 15, as well as providing motive force to compress the support structures 16 (and associated tiers 12) into a stacked nested configuration. As shown in FIG. 16, powered base member 150 includes a power transfer mechanism (such as a motor having an attached gear or pulley) connected to a drive wheel 158. Drive wheel 158 can likewise be connected to one or more additional drive wheels 159 to provide additional traction while pushing or pulling the lower tiers to or from a stacked configuration.

Having described the invention it should be understood that the foregoing description of the invention is intended merely to be illustrative thereof and that other modifications, embodiments and equivalents may be apparent to those who are skilled in the art without departing from its spirit.

The present invention is not intended to be limited to a device or method which must satisfy one or more of any stated or implied objects or features of the invention and should not be limited to the preferred, exemplary, or primary example(s) described herein. Modifications and substitutions by one of ordinary skill in the art are considered to be within the scope of the present invention, which is not to be limited except by the allowed claims and their legal equivalents.

Claims

1. A tier locking system for allowing highest-to-lowest tier retract in a telescopic seating assembly that includes a plurality of seating tiers with seating platforms supported by movable supports structures that move relative to one another along a first direction, the tier locking system comprising: a first tier catch having a substantially vertical tier catch body, a strike plate and a pivot tab extending from one side of the tier catch body, and a cam follower extending from an opposite side of the tier catch body, wherein the tier catch is pivotally attached to a first support structure;a first catch plate having a substantially vertical body attached to a second support structure and a substantially horizontal lock arm extending over the first support structure in the path of the strike plate of the first tier catch in the first direction; anda second catch plate having a substantially vertical body attached to a third support structure, a substantially horizontal lock arm extending over the second support structure, and a cam arm extending from the lock arm in the path of the cam follower in the first direction;wherein the interaction of the cam arm and the cam follower caused by movement of the first support structure relative to the second support structure in a horizontal direction acts to pivot the tier catch about its pivot axis.