US 3222827 A
Description (OCR text may contain errors)
Dec. 14, 1965 P. A. SMITH GRANDSTAND CONSTRUCTION 6 Sheets-Sheet 1 Filed Jan. 25, 1962 INVENTOR. 1 904, 7. 6m! 77/.
Dec. 14, 1965 P. A. SMITH GRANDSTAND CONSTRUCTION 6 Sheets-Sheet 2 Filed Jan. 25, 1962 INVENTOR. P904, 69. QSM-r 77% Dec. 14, 1965 P. A. SMITH 3,222,827
GRANDSTAND CONSTRUCTION Filed Jan. 25, 1962 6 Sheets-Sheet 5 llcl w 82 M ---/30 90 J6- 0 so I as I: 90 I -54 54 use, I l l I 1 7e. 24" i '1 I I l l s INVENTOR. A404, 67 QSMI M #1 I I E II A M M 74 120$ J 9 7' TUBA/.5 18.
Dec. 14, 1965 sMlTH 3,222,827
GRANDSTAND CONSTRUCTION Filed Jan. 23, 1962 6 Sheets-Sheet 4 4s 4 as I O 4 666, B4 6 46 INVENTOR.
Dec. 14, 1965 P. A. SMITH 3,222,827
GRANDSTAND CONSTRUCTION Filed Jan. 23, 1962 6 Sheets-Sheet 5 I NVENTOR Paul. 9. @071 TH.
6' 7- TOEA/E. KS.
Dec. 14, 1965 P. A. SMITH GRANDSTAND CONSTRUCTION 6 Sheets-Sheet 6 Filed Jan. 25, 1962 WiEEI-ZEEH 2 4 70 INVENTOR.
United States Patent 3,222,827 GRANDSTAND CONSTRUCTION Paul A. Smith, Gibsonia, Pa., assignor to Playtime Equipment Corporation, Mars, Pa., a corporation of Pennsylvania Filed Jan. 23, 1962, Ser. No. 168,113
3 Claims. (Cl. 529) This invention relates to a retractable grandstand construction which is usable in extended position to provide tiers of horizontal seats for spectators whereby a substantial audience can be seated for indoor events. The grandstand is readily retractable from its extended position of use, to an internested compact position in which condition it is stored and occupies a minimum of valuable space within an indoor location.
Numerous indoor foldable grandstands have been proposed and many of them embody strength, stability and ease of actuation to a degree. I have found however that those grandstand structures which have the required degree of strength and stability preventing them from swaying and moving with audience motion, are proportionately more diflicult to extend and retract. Similarly, those grandstands having a facility of retraction and extension tend to be unstable and will pitch noticeably under some conditions such as an audience rising simultaneously or swaying from side-to-side in unison. Also, certain of these grandstands will tremble and tend to move retractively as the grandstand begins to fill up under the momentum of the audience moving upwardly in the grandstand to take their places.
All of these described instabilities, even if they are not indicative of failure of a grandstand, can produce apprehensions in the audience and are generally unsatisfactory for that reason.
Another severe shortcoming which I find in numerous foldable grandstand constructions is that the sections are interconnected by articulative linkages having multiplying lever ratios. During retractive movement, all of the linkages and pivot connections must work satisfactorily or the grandstand resists retractive movement and this is particularly the case if the binding occurring at one linkage is multiplied through a series of levers. As a result, the linkages must be made very loose to insure freedom of movement and consequently such looseness of connections fails to bind the sections rigidly together.
It is one of the objects of the present invention to provide a retractable (i.e., internesting sections), grandstand which is rigidly supported in its extended condition of use so that it is more stabilized against sway and retractive movement during all conditions of audienece use, i.e., during seating, standing, while the audience is emptying or filling the grandstand or moving about therein or following various audience motions.
It is a further object of the invention to provide a stable grandstand construction which is relatively easy both to extend and to retract but without compromising the strength advantages of the grandstand against accidental or unstable movements.
A further object of the invention is to provide a series of grandstand sections which can be retracted or nested together by relative movements of substantially frictionless character in order to reduce the effort (either manual or power actuated), required to extend the grandstand sections or internest them as desired.
A further object of the invention is to provide a grandstand comprised of a plurality of individual sections each of which is independently supported on floor-engaging wheels or other antifriction means so that one section cannot bind the retracting or extensible movement of another section.
It is another object of the invention to provide a substantially frictionless connection between successive sections of grandstand whereby the grandstand sections are simultaneously guided along a prescribed path of retractable and extensible movements, and appropriate vertical spacing is maintained between portions of each section in order to reduce binding of any sort between said sections.
It is a further object of the invention to provide a novel locking and reinforcing means between successive sections which is located at the seating level of the audience in order to resist various loads on the grandstand at their point of input. In other Words, the forces which arise during seating of an audience and causing the grandstand to retract or nest are resisted adjacently to the force input point in order to reduce leverage effects of these forces. The retractable grandstand sections are thus held against untoward extension, retraction, and lateral movements by resisting such movements in the vicinity of the seat and footboard portions thereof.
A further object of the invention is to provide a foldable grandstand in which the individual sections thereof are independently retractable or extensible so that the resistance of the sections is noncurnulative. The grandstand as a whole is serially or successively retracted with the respective retractive movements of each section providing an unlocking effect for succeeding sections.
Another object of the invention is to provide a novel actuation and support mechanism for the forward row by which its weight is selectively transferred from roller support to frictional sliding support on the floor to prevent inadvertent retractable or nesting movement of the front row and thereby succeeding rows are prevented from accidental retraction movement.
Another object of the invention is to provide a retractable grandstand having sections which include both horizontal and diagonal braces to obtain rigid vertical support for the sections; yet, the braces of the sections are disposed relatively to the braces of the next succeeding sections so as not to cause binding or interference which might preclude complete internesting of one section within the next. Consequently, the sections are rigidly supported but the rigid support does not detract from complete internesting of the sections into a compact condition.
Other objects and features of the invention will become apparent from a consideration of the following description which proceeds with reference to the accompanying drawings, wherein:
FIGURE 1 is an end View of the grandstand when it is fully extended and ready for usage;
FIG. 2 is an end view of the grandstand looking in the same direction as shown in FIG. 1 and illustrating the fully retracted or internested position of the grandstand;
FIG. 3 is a section view of the grandstand taken on line 3-3 of FIG. 1 when it is partially extended showing relative lateral positions of successive rows;
FIG. 3A is a detail view of the base support located at the lower part of the grandstand;
FIG. 4 is a sectional view taken on line 44 of FIG. 5, the cross-brace being broken to bring the ends of the frame closer together, and illustrating the guide rollers which serve a number of functions including guiding the retractable sections and effecting proper vertical spacing of the stepped sections;
FIG. 5 is an enlarged detail view illustrating the unlocking procedure wherein the lowermost section shown is in the process of moving rightwardly in a retracting or nesting direct-ion to effect unlocking of the latch mechanism for the next vertical section (the intermediate section) to permit its retracting or nesting movement;
FIG. 6 is a detail end view of the column portion of a complete grandstand section detached from the other secitons and shown together with its interconnected structure including the base, cantilever channel, footboard and seatboard members;
FIG. 7 is a detail view of the base portion provided for the column at the outer end of the bleacher viewed from the left-hand end of FIG. 3;
FIGS. 7A and 7B are side and top views respectively of the wheel support mechanism of FIG. 7 and the manner which the grandstand sections are vertically supported except when live load (spectators) partially or fully occupy the stand;
FIG. 8 is a sectional view of the row-lock lever taken on line 8-8 of FIG.
FIG. 9 is a rear view of the grandstand in open or nested condition and looking in the direction of the arrows 9-9 of FIG. 2;
FIG. 10 is a detailed view of the row-lock mechanism and channel illustrating in full line and dotted line positions how the row lock is actuated by the roller which guides the upper end of the column portion of the grandstand and how the sections are disposed in maximum extension and retraction;
FIG. 11 is a detail view of the forwardmost ro'w illustrating in dotted line position the components when the grandstand is extended initially and then actuated to full line position to rest the forwardmost row on pads rather than rollers whereby the forwardmost row will not be inadvertently actuated in closing or nesting direction to produce unintentional closing or nesting of successive sections; and
FIG. 12 is an alternate embodiment for raising and lowering the forwardmost section from roller to a fixed pad support.
Referring now to the drawings, and particularly to FIGS. 1-3 a grandstand, designated generally by reference numeral 10, includes a plurality of telescoping sections each of which intermediate the largest section 12 and smallest section 14 consists of a frame having an end view as it appears in FIG. 6, and an internal support of similar construction except the base as shown in FIG. 3A. Each of the movable grandstand sections comprises a pair of frames which are related to each other as righthanded and left-handed constructions (or inboard and outboard elements), these frames being spaced apart to reduce the unsupported length for the seatboards and footboards respectively. A typical set of frames is designated generally by reference numerals 18 and 20 (FIG. 3) and an understanding of one of the frame sets is sufficient to understanding of the others, except the front or foremost row to be described hereinafter.
The sections comprised of the respective frame sets become progressively narrower and shorter proceeding forwardly, i.e., away from the fixed wall 22 so that the sections will nest one in the next to provide a compact nested relationship of the sections when they are fully retracted to the condition shown in FIG. 2 wherein the grandstand structure occupies substantially less volume than is the case when it is fully extended. When retracted the grandstand thereby occupies less of the useful space in an indoor structure such as a gymnasium, arena, auditorium or the like.
Referring now to details of the frame 20, there is provided a vertical column 24 (FIG. 6) comprising two spaced interconnected members 26 and 28 which may be angular or tubular in cross section depending upon design requirements, these members being interconnected by transverse plates 30 or the like which are riveted or otherwise secured at 32 (FIG. 7) to the two upright members 26, 28. At the top of the two members 26, 28 is an angle 34 (FIG. 4), one leg of which provides a pedestal 36 onto which is settled the seat section of the next higher row when the stand is loaded and which is vertically supported by the column 24.
Vertical support load is transferred through each column 24 to a base 38 to which the column 24 is connected by welds 40 (FIG. 7) and a brace 42. The base 38 is supported on floor-engaging wheels 44 which are mounted on axles 46 at the ends of levers 48 having pivot connections 50 with the base 38. The wheels are moved downwardly by rotary movement of the levers 48 about pivots 50 in the direction of the arrows (FIG. 7) by a caged spring 52 which is compressed bet-ween side 54 and washer 56 to urge the stem 58 upwardly and bringing the eye 60 and crosspin 62 therewith which passes through aligned elongated openings 64 of ends 66, 66a of levers 48. The compression of spring 52 is adjustable by means of nut 68 which can load the spring 52 to any degree determining the resistance of levers 48 to turning and thereby establishing the point at which the weight from columns 24 can overcome their springs 52 and by turning levers 48 transfer the support load from rollers 44 to pads 70 which settle onto the floor in supportive engagement therewith. The spring 52 is adjusted so that the grandstand weight proper is sustainable on the wheels 44 but the weight of an audience is taken mainly through the pads 70 because this added weight overcomes spring 52 and causes the base 38 to settle onto the floor 72 engaging the pads 70 therewith.
Each pair of columns comprising a frame is interconnected by horizontal braces 74 and alternate braces have in addition thereto an X-brace 76 acting in conjunction with members 74 (FIG. 4) to resist swaying movement of the sections as well.
At the top or head of each column is a vertical leg 80 (FIG. 4) of angle 34 having a roller 82 with flanges 84, the roller being supported on an axle 86 including a striker pin 88 which serves as an actuator, successively releasing or unlocking the rows and thereafter permitting retraction thereof. The rollers 82 serve a plurality of functions, among which is to guide the movement of the sections 18, 20 so that the opposite ends thereof do not advance one ahead of the other; the rollers also serve as antifriction means facilitating extension and retraction of the sections; the rollers also define the vertical displacement between successive rows in the retracted positions thereof; the roller axles, acting through striker pins 88, serve to unlock the sections which are locked in extended positions, by gravity row locks (FIGS. 8 and 10) except when it is desired to nest the stand into closed position; and the rollers interlock through slot 90 with channel 94 of the next higher frame to transmit longitudinal (sway) force from the section to the X-brace and thereby minimize bending of the columns 24, 24', 24", etc.
Each roller 82 is received in a complementary guideway slot 90 of a box-shaped cantilever channel beam 94 projecting forwardly from the next higher section, this section serving as a weight-transmitting cantilever beam which settles down into contact with the pedestal 36. The channel associated with frame 20 is designated by reference numeral 94 (FIG. 6) and is welded at 98 to uprights 26, 28, the channel member 94 providing a suitable support for a footboard 100 extending the length of the grandstand and secured by bolts 101 (see FIG. 5) or the like to the spaced cantilever beam supports 94. At the end of the cantilever beam 94 is a strap steel member 102 welded at 104 and so bent as to provide a resting surface 106 for seatboards 108 which are secured thereto by bolts or the like 110.
At the end of each cantilever beam support 94 is an abutment 112 which may comprise an end portion of the strap 102 and which is contacted by the angle 34 of the column 24' of the next lower tier (FIG. 5) in order to limit its extending movement. As the lower section having tier column 24 is being fully extended, lever 114 having a transverse hook end 116 and supported through pivot 118 on the column 24' (FIG. 5), engages its cam face 120 with surface 122 at the forward or projected end of 94, thereby rotating lever 114 counterclockwise about pin 118 until hook face 124 clears surface 122 and the weight of the depending arm portion 126 overbalances the hook end 116 at the opposite side of pin 118, causing the hook face 124 to engage the abutment 112 and thereby clamp the abutment 112 between the hook face 124 and the leading end of the angle 34. The lower column 24 (FIG. 5) is thus prevented from rightward movement relative to the channel 94 which is associated with the frame section 24. In this manner the successive tiers are held against retracting, closing or nesting movement by means of their locking levers 114 which form latch connections at the outboard ends of the grandstand.
It will be further noted that the locking is effected at the spectator level where input forces tending to cause retraction are first communicated to the grandstand, it being highly advantageous to resist these forces as closely as possible to their location of input to the grandstand in order that they will not be multiplied through any leverage prior to meeting an effective resistance. When the lower column 24' (FIG. 5) reaches its maximum extension, its attached roller 82 overlies a concave enlargement 130 of track 90 in order that no substantial vertical load will be carried by the roller 82 and its axle 86. Thus, assuming a substantial load in the direction of the arrow F (FIG. 5), the column 24 will depress, carrying the roller there with through a distance represented by the clearance of roller 82 with the bottom of the concave notch 130 and the column 24 will come to rest on its fixed pad 70. Furv thermore, the cantilever channel beam 94 provided by column 24 will move downwardly and settle on the top of column 24 (FIG. 4) to distribute such load between columns 24 and 24. Force F from a standing load on footboard 100 is equivalent to a seated load on seatboard 108 carried by column 24 and is resisted as described.
Assuming a substantial audience weight imposing a force F in FIG. 5 the cantilever support 94 carried by column 24" will bend downwardly because of the resilient support at the foot of the column 24" and end 112 thereof will come downwardly into resting position on the pedestal 36 (FIG. 4) of the column 24. There is very slight clearance C (FIG. 4) which is less than the clearance C between the upper edge of each guideway opening 90 and its companion roller 82 so that the force F is transmitted to the intermediate column 24 without imposing any force on roller 82. Likewise, any force transmitted from seatboard carried by column 24" is communicated through its cantilever beam 94 to the intermediate column 24 and without passing through the roller 82 which is located over the intermediate column 24 in FIG. 5. In this way, the rollers 82 can be made of non-weight supporting dimension and are therefore small enough to be non-obstructive. Likewise, the rollers can be of inexpensive construction owing to their reduced size and they can be constructed primarily for this function as frictionless nonweight-supporting members which guide and space the sections as they move along their prescribed paths of motion.
During closing or nesting movement of the sections, each section is successively released and allowed to retract, one section being unlocked by movement of the next lower section into nested relation therewith. Thus, the grandstand nests by movement from front to back starting with the first section, or forwardmost section, which is completely retracted and when brought into nested relation with the next section, will effect unlocking of that section and so on to successive sections which are serially unlocked, and nested into their next higher complementary section to produce an unlocking of that section until all are nested into one large internested package shown in FIG. 2 wherein all of the sections are nested against the highest section 138 secured by anchor bolts 140 to the wall and floor. When no wall is available, the highest section 140 can be bolted or anchored to the floor if desired.
The nesting operation can proceed only by first initiating nesting movement of the lowermost section, i.e., the one at the extreme left-hand end of FIG. 1, one section then proceeding to unlock a succeeding section andso on until all are nested together. During nesting movement, each roller 82 raises upwardly from the concave portion and into the rectilinear portion of the guideway slot 90, guiding its respective column 24 (FIG. 5) rightwardly relative to the foot and seatboards and projecting channel 94 of the next higher section.
What limits the extent of retraction of each section one within the next is that each movable column moves into engagement with the horizontal braces 74 of the next higher section at which time the seatboard 108 just fits beneath the projecting cantilever beam channel of the next higher section, the proper vertical clearance between these sections being assured by the rollers 82 of the respective sections which serve as spacers between the columns and overprojecting cantilever beams of the contiguous section.
Since each section, comprised of a set of frames, is independently mounted for nesting and extending movements, nesting forces are developed between the sections by forming a thrust transmitting abutment connection therebetween. Thus, starting with the lowermost section of FIG. 1 a force exerted to the right will cause one section to fold within the next section and the retractive foroe is transmitted between these sections through the abutting relation of the shorter columns with the horizontal braces 74 of the next succeeding section. For ex ample, in FIG. 5 the section comprised of column 24' will move to the right relatively to columns 24 and its interconnected beam 94, footboard 100 and seatboard '108 until engagement is effected with reinforcement member 74 which limits further retraction of the columns 24' and provides a force-transmitting connection between the sections whereby both are then translated together in a retractive direction.
During retraction, the base portions 38 at the outboard ends of the grandstand (FIG. 3) overlap slightly to provide guidance for the sections as they move retractively into nested relation one within the next. The inboard sides of each section, still referring to FIG. 3, are supported on bases which are not elongated and are supported on a single vertical spring mounted roller as indicated in FIG. 3A.
As previously mentioned, the lowermost sections are impeded from free retractive movement because if they should retract accidentally this will permit successive roller supported sections to nest. Therefore, special precaution is taken to transfer the weight of the endmost section from rollers to the floor so that sliding movement is retarded, preventing retraction unintentionally. When retraction is intended, by simple actuation, the weight can be transferred from pads onto rollers to commence retraction, by raising the front apron which releases spring 52 thereby lowering rollers 44 as shown in FIGS. 12 and 11, and elevating the front section off its pads 70.
Referring to FIG. 11, one such means for the endmost section comprises a column 162 and base 164 having a footboard 166 and seatboard 168 fastened to the base 164 through a bent strap section 170 welded at 172 to the base 164. The base 164 is supported on rollers 44 which are mounted on the ends of levers 48, said rollers being pivoted at 178 on the base 164. The levers are actuated about their pivots 178 by a caged spring 52 having a spring load which is regulatable by a nut 182 which can be turned to any preferred position on the threaded stem 184 so that the rollers 44 are held in engagement with the floor 72 to support the Weight of the grandstand, for retracting or extending the stand.
To insure that the front row will not move inadvertently I provide that once the grandstand is extended the weight of the forward row is transferred from the rollers 44 to friction pads 70 which are brought into engagement with the floor 72, this being accomplished by means of an apron 190 having a hinge connection 192 with the strap 170 and swung downwardly from the dotted line position to the full line position (FIG. 11) and bringing the striker plate 194 into engagement with the arm 195 of bellcrank 196 pivoted at 198 and moving the bellcrank arm 200 from dotted line position to full line position. The arm 200 engages the threaded stem 184 and forces the eye 202 downwardly, said eye having a pin connection 204 with the ends of levers 48 and turning the levers about their pivots 178 to raise the rollers out of engagement with the floor 72 and bring friction pads 70 into engagement with the floor 72.
Thus, responsively to lowering of the apron 190 from dotted line position to the full line vertical position where it is latched in place, it is possible to raise the forwardmost rollers 44 and frictionally resist inadvertent movement of the forward row. The apron 190 is generally provided with gripping openings 208 to facilitate manual operation of the apron 190.
A second embodiment of the lowering mechanism which is illustrated in FIG. 12 comprises, in place of a bellcrank, a simple lever 210 which is pivoted at 212 and has a roller forming a cam follower 214 at its ends 216 so that the opposite end 218 will move angularly effecting vertical displacement of the stem 184 which provides the same operation as described in the embodiment of FIG. 11. The lever 210 is caused to pivot from its dot-ed line position wherein the rollers are lowered, to the full line position wherein the rollers are raised by means of lowering apron 220 and causing cam end 222 to engage the follower 214. The apron 220 is locked in place by a detent 224 on the cam 222 so that the follower 214 will snap into the detent 224 by the compressive action of spring 52 thereby locking the rollers in a raised position when the apron 220 is lowered to full line position. The apron can include openings 225 or the like to form a handle facilitating raising and lowering of the apron.
In all other respects, the forward section is the same as described in FIG. 6.
In operation, to extend the grandstand manually, the apron 190, assuming the use of the embodiment illustrated in FIG. 11, is pulled forwardly allowing the weight of the forwardmost set of frames to transfer from the friction pads 70 to rollers 44.
The pulling effort manually exerted from gripping openings 208 is exerted on section 160 which rolls forwardly on rollers 44, its forward movement being guided by the small rollers 82 which are longitudinally movable within the guideways of the box-shape cross-section cantilever beams of the next higher section. The section 160 continues to move forwardly relatively to its internesting section until the column 162 bottoms against the abutment 112 carried at the end of the projecting cantilever beam on the adjacent section and thereby forming a drawing connection between the first or forwardmost section which is the smallest section, and the next succeeding section which then proceeds to move outwardly on its roller supports, the two sections now moving in unison until the columns of the second section bottom against the projected ends 112 on the cantilever beams of the next higher or third section and then the first, second, and third sections move in unison.
The action can be easily understood by reference to FIG. 6 which, except for the stationary frame and smallest frame, illustrates the basic frame support for all of the outboard intermediate frame sections, and FIG. 3A for the inboard frame sections. The outboard and inboard frame sections shown in FIGS. 6 and 3A differ from one section to the next only in the change in height and the distance by which the sections of FIGS. 6 and 3A are spaced apart (FIG. 3). Each section, it will be seen, is individually mounted on its floor-engaging rollers 44, and is guided at its uppermost end by a small 8 roller 82 (FIG. 4) and provides an abutment 112 limiting relative movement of its smaller internested section forwardly thereof in an extending direction and forming a drawing connection whereby extensible drawing effort is communicated from one section to the next while the grandstand is being extended.
The sections are rigidly reinorced by means of both diagonal and horizontal braces, yet these braces do not detract from complete internesting of one section into another. The grandstand, as a whole, is thereby rigid and does not sway perceptibly yet it may be internested to a compact condition without interference of one section to the next.
The described extension operation continues with one section pulling the next until all of the sections are spaced equidistantly from each other and each section reaches its maximum displacement from the fixed end section 138 adjacent the wall 22 which is held against movement by the anchor members 140.
As each section moves outwardly on its extending travel, it rolls on floor-engaging rollers 44, the weight of the grandstand being insufficient to overcome the springs 52 which are located at the base of each movable section and which rotate the rollers 44 downwardly in opposition to the weight of the grandstand.
As the sections travel outwardly they are guided along a prescribed path of extending movement by virtue of the overlapping base portions (FIG. 3) at the outboard ends of the section, these overlapping base portions serving to provide a suitable guidance. The upper ends of the sections have small diameter rollers 82 equipped with flanges 84 to prevent one side of the section from moving ahead of the other. Thus, referring to FIG. 3, and selecting any one of the movable sections, should one outboard end of the section, say the right-hand end, move ahead of the left-hand outboard end, the roller 82 (FIG. 4) at the right-hand end will bind within the slotted guideway of the cantilever beam projecting from the next higher section and the only way in which this binding can be relived, is by straightening the section so that it travels forwardly with each end advancing at the same rate and to the same extent.
Just prior to the engagement of upper end of column 24 with abutment 112 on the cantilever beam 94 of the next higher section, the cam portion of row lock 114 engages the inner surface 122 of the abutment 112 and is rotated about its pivot 118 (FIG. 6) so that the hook 116 passes beyond the abutment 112 and the weight of the depending arm portion 126 rotates the lever 114 to a normal position shown on the column 24 (FIGS. 5, 10) thereafter preventing retractable movement of column 24 relatively to the next higher column 24", there being two such locks at each of the opposite outboard ends of the grandstand. When the grandstand is thus fully extended and each section is locked against further extensible or retractable movement it assumes the position shown in FIG. 1, and no nesting movement can take place unless it occurs serially, i.e., progressively from one section to the next, starting from the lowermost section. To guard against inadvertent nesting or closing movement of the lowest section, the last act performable upon extending the grandstand is to raise the rollers 44 out of engagement with the floor and transfer the weight of the forward most section from the rollers to the pad 70 which are brought into engagement with the fioor 72 to frictionally resist retractive movement. Thus, it is unlikely to initiate by inadvertence a nesting operation of the grandstand. Raising of the rollers 44 occurs by pivoting the apron in the case of the embodiment shown in FIG. 11 or the apron 220 in FIG. 12 to compress spring 52 and concurrently pivot levers 48 in opposite directions about their pivots 178 and thereby raising rollers 44 which has the effect of settling the weight of the forward section upon the pads 70.
In the grandstand there is sometimes an audience surge upwardly by simultaneous movement of numbers of people all climbing to their seats. This tends to retract the grandstand sections but is resisted by the row-lock levers 84 which, being located in proximity with the force tending to retract the grandstand, is capable of resisting these forces at their point of input. Thus the described forces are not multiplied by transmittal through leverages or the like.
The dead weight of each section is carried through its base but the audience weight is distributed difierently. Considering FIGS. 1, 4, and 6, assuming that sufficient seated audience weight designated F on seatboard 108 (FIG. 5) the column 24 will tip slightly forwardly so that the cantilever beam will settle downwardly through the clearance C (FIG. 4) transferring the audience weight onto column 24 of the adjacent smaller section. Note that when the sections are extended there is a column for each seat section at the outboard and inboard ends directly beneath the ends of the rows and intermediate the rows of seatboards 108. Thus, the audience seating load is transferred from one section to the succeeding smaller section where it is borne on the column members thereof. Audience load is not sustained to any degree on the small rollers 82 since the cantilever beams 94 will settle down into solid supporting engagement before the clearance C (FIG. 4) is taken up and which would otherwise transmit a major part of the audience load from the cantilever beam to the roller 82 before it reaches column 24. In other words, the clearance C is smaller than the clearance C The next higher section which carries the seated audience load F causes the beam 24" to deflect forwardly until clearance is taken up between the cantilever beam 94 secured to 24" and the column 24 and thereafter the seated audience load F is sustained directly by column 24. If the audience should then rise, standing on footboard 100 secured to beam 94 of column 24 the load F then deflects column 24 and its beam 94 and the beam takes support on column 24 which sustains the standing audience load F Similarly the standing load F of the audience transfers to the next smaller column adjacent 24' (FIG. 5).
From the foregoing it will be seen that each section is independently movable and is self-supporting. Seated audience load is transferred from one section to the next lower section; and, the same audience load, but standing, is transferred to the next succeeding lower section.
When the weight sustained by any one section is great enough, the spring 52 at the base of the section is overcome and the weight settles the section downwardly until the pad 70 comes into the contact with the floor 72.
When it is desired to retract the grandstand the forwardmost section 160 is actuated to raise the pads 70 out of contact with the floor and onto rollers 44, this being accomplished by pulling the apron 190 (FIG. 11) from the full line position to the dotted line position and allowing the spring 52 to move the stern 184 upwardly and turning the levers 48 in opposite directions about the pins 178 to lower the rollers 44. Then, by applying translating effort on the forward section in the direction of the wall 22, column 162 and the entire section 160 is moved toward the right until the guide rollers carried by column 162 come into contact with and pivot the row-lock levers (FIGS. 8, disengaging their hooking connection with stop plate 112 on the cantilever beam which projects forwardly from the next higher section. As shown in FIGS. 4, 5 and 8, each outside roller 82 has a striker pin exten sion 88 which engages the lever and (FIGS. 8, 10) tilts it in the direction and manner indicated by the lower row lock 114, FIG. 10, so that the column 24 carrying the released row lock will travel rightwardly, being guided by its roller 82 traveling within the guideway slot of the cantilever beam projecting from the next higher section.
During retraction the roller 82 rides within the narrower slot of the guideway 94, thus fixing the vertical position of the seatboard with respect to the contiguous lower and higher sections and thus insuring minimum binding between the sections as they slide nestibly together. Retracting, or nesting movement, once it is initiated, progresses from one section to the next, the rollers 82 of one section serving to unlock the row locks of the next higher section so that nesting or closing movement cannot take place out of turn but proceeds in series one after the next until all are nested one within the other and are contiguous with the largest section 138 which is relatively fixed and provides an immovable shield for the other sections in order to prevent damage thereto while they are stored.
As the sections move together, what limits the extent of retractive movement and communicates retractive force from one section to the next is the engagement of the columns 24 of the lower section with the horizontal cross members 74 of the next higher section. As an example, referring to FIG. 5, the left-hand columns 24' will move toward the right, nesting that section within the intermediate section having columns 24, until columns 24' engage the horizontal braces 74 secured to columns 24. The columns 24 then becoming unlocked are free to move toward the right. Retractive effort is thus transmitted from one section to the next by the engagement of the columns of the lower section with the horizontal cross-beam rein forcement of the next higher section, the unlocking of each section being dependent upon the next lower section to produce serial, i.e., progressive nesting of one section into the next and in succession.
In assembling the grandstand, it is convenient to ship sections of the grandstand as they appear in FIG. 6 and then assemble them into frames by attaching the horizontal reinforcement members 74 after the lower section is fitted in place. This order of assembly prevents the sections from moving apart and they are interlocked both retractively and extensively. Once the frames are constructed and assembled into sections, the seatboards and footboards are then bolted in place. The entire assembly procedure can be performed by a semi-skilled crew in the shortest possible time.
To provide additional reinforcement, diagonal braces 76 are added to alternate sections and the pairs of sections at the higher rows can be tied together by additional braces to further eliminate any degree of sway in the stand.
The grandstand describe-d is capable of meeting all of the structural and functional requirements of each State and Territory of the United States as well as requirements of American Seating Association, and is capable, from actual tests, of sustaining vertical, lateral and other tangential loads more than sufiiciently to meet the conditions presented with a capacity load adult audience. Moreover, the stand is capable of sustaining this load assuming the audience movements such as occur by mass movement surging upwardly to fill the stand and downwardly to empty the stand. The construction is further adapted to resist lateral stresses of 24 pounds per lineal foot to prevent sway and consequent buckling of the stand. It is known, for example, in numerous indoor sports that the audience will sway in unison or move in unison imposing peculiarly high and stressful loads on a grandstand. My construction is capable of meeting these contingencies.
Although the present invention is described in connection with a single example embodiment it will be appreciated that this is in no way limitative but instead is illustrative thereof. It is to be reasonably expected that those skilled in this art can make numerous revisions and adaptations of the invention to meet individual design requirements and it is intended that such revisions and variations of the invention, as incorporate the herein disclosed principles, will be included within the scope of the following claims as equivalents of the invention.
I claim as my invention:
1. In a movable grandstand, a forward section having a horizontal seating surface, roller means providing vertical support for said section and disposed in rolling support with a floor, lever means carrying said roller means and pivotally secured to said section for lowering said roller means into rolling support with said floor and for raising said roller means whereby the weight of said section is transferred from said roller means to said floor, spring means compressible between an extension of said lever means and a portion of said section for pivotally moving said roller means into rolling engagement with said floor, actuator means depending from a forward edge portion of said seating surface and pivotally secured to said forward section, cam means carried by said actuator means, and arm means pivotally secured intermediate of its ends to said section and having a cam follower at one end thereof engageable with said cam means and at the other end engageable with the extension of said lever means to compress said spring means whereby said roller means are raised to transfer the weight of said section from said roller means to said floor.
2. A foldable grandstand, comprising a plurality of grandstand sections each proportioned to receive nested therein lower grandstand sections contiguous thereto; each of said grandstand sections comprising a set of substantially vertically positioned columns each having a support pedestal including antifriction rolling members permitting free movement of the grandstand sections over a supporting surface; means for resiliently connecting said antifriction rolling members to the supporting pedestals whereby each of said grandstand sections is movable toward and away from contact with said supporting surface; lateral brace means extending between adjacent columns of each grandstand section for reinforcing said grandstand sections against lateral swaying movement; a plurality of cantilevered weight carrying members disposed in vertically stepped relation, each of said cantilevered weight carrying members being secured at one end to one of the columns of one of the grandstand sections and projecting horizontally therefrom over the upper end of the column of the next lower grandstand section, each of said cantilevered weight carrying members normally being vertically spaced from the upper end of the column of the next lower grandstand section and being displaced into engagement with the upper end of the column of the next lower grandstand section when subjected to the weight of an audience; means forming a substantially friction-free guiding connection between adjacent grandstand sections for guiding each grandstand section during movement thereof toward a nested position and a fully extended position of use, said means forming a substantially friction-free guiding connection comprising a roller member rotatably supported at the upper end of each of said columns, and ecah of said cantilevered weight carrying members having a longitudinal recess receiving the roller member of the next lower grandstand section and whose width is greater than the diameter of the roller member, each of said roller members being spaced from the edges of said longitudinal recesses whereby movement of said roller members relative to said cantilevered weight carrying members is substantially friction-free and whereby ecah of said grandstand sections is displaceable into engagement with said supporting surface independently of the other of said grandstand sections; and means for limiting the extending movement of said grandstand sections comprising abutment members carried by said cantilevered weight carrying members and positioned for engagement with corresponding abutment members carried at the upper ends of the subjacent columns.
3. The foldable grandstand of claim 2 wherein said weight carrying members comprise C-shaped channel members having vertical downwardly and upwardly projecting flanges defining said longitudinal recess, each of said roller members being horizontally supported and positioned centrally within said longitudinal recess.
References Cited by the Examiner UNITED STATES PATENTS 2,183,056 12/1939 Albach 529 2,183,057 12/1939 Albach et al 529 2,706,835 4/1955 Ullom 529 2,870,492 l/ 1959 Chervenka 529 2,877,507 1/1959 Walworth 5210 3,088,176 5/1963 Delf et al 529 3,107,399 10/1963 Murphy 5210 OTHER REFERENCES Closed Deck Roll Out Gym Seats: (publication), published by the Hussey Mfg. Co. Inc., North Berwick, Maine, November 1960, pp. 2, 4, and 7.
Berlin Bleacher: (publication), published by Berlin Chapman Co., Berlin, Wisconsin, pages 2 and 3 relied on, November 1960.
FRANK L. ABBOTT, Primary Examiner.
WILLIAM I. MUSHAKE, EARL J. WITMER,
JACOB L. NACKENOFF, Examiners.