Abstract:
Playground apparatus of the teeter-totter or seesaw type for a plurality of riders which is characterized by completely individual movement of each rider wherein the movement of any one rider does not affect the movement of any other riders, as follows. A plurality of spaced-apart rocker arms are separately pivotally mounted to a vertically disposed support without interconnection to the other of the rocker arms for up and down movement. A biasing member is provided for each of the rocker arms for individually biasing the rocker arms in an upward direction and for allowing downward movement against the bias thereof. A rider supporting unit is on each of the outer ends of each of the rocker arms.

Description:
FIELD OF THE INVENTION 
     This invention relates to playground apparatus of the teeter-totter or seesaw type for a plurality of riders which is characterized by completely individual movement of each rider wherein the movement of any one rider does not affect the movement of any other rider. 
     BACKGROUND OF THE INVENTION 
     Playground apparatuses of the teeter-totter or seesaw type have become quite popular for children in recreational areas including public parks, nursery or day schools, back yards, etc. These apparatuses are generally of the type utilizing a central support, a plurality of spaced-apart rocker arms containing a rider supporting unit or seat on the outer end thereof and being connected together and to the support at the inner ends thereof. The apparatuses may include some sort of biasing means for biasing the rocker arms thereof in an upward direction. 
     One of the more popular of these teeter-totter or seesaw type playground apparatuses is marketed by Game-Time Inc. of Hillsdale, Michigan under the name &#34;BUCK-A-BOUTS&#34; and is purportedly constructed in accordance with their Ahrens U.S. Pat. No. 3,836,140, issued Sept. 17, 1974. 
     Additional examples of these types of playground apparatuses may be seen in the following additional U.S. Pat. Nos. considered with respect to the present invention. 
     
         ______________________________________U.S. Patent Number          Inventor       Issue Date______________________________________1,566,765      A. Natale      Dec. 22, 19252,130,438      P. H. Westerlund                         Sept. 20, 19382,198,947      E. V. Olson    April 30, 19402,542,359      I. J. Rocklin  Feb. 20, 19513,089,699      N. F. Flesch   May 14, 19633,292,924      R. S. Wormser  Dec. 20, 1966          et al3,390,879      L. F. French   July 2, 19683,675,919      R. L. Ewers    July 11, 1972______________________________________ 
    
     All of the teeter-totter or seesaw type of playground apparatuses known to applicant and exemplified in the above-identified U.S. Patents include an interconnection between each of the spaced-apart rocker arms forming part of the playground apparatuses such that movement of one rider will affect and control movement of the other rider, e.g. downward movement of one rider on one rocker arm causes upward movement of an oppositely disposed rider on an oppositely disposed rocker arm, etc. While this sort of ride or movement is desirable in some playground apparatuses of this type, it is undesirable in other uses of playground apparatuses of this type; particularly, when different sizes and weights of riders are involved inasmuch as the larger and heavier rider will in effect completely control the ride and movement of the smaller and lighter rider. 
     Summary of the Invention 
     Accordingly, it is the object of this invention to provide playground apparatuses of the teeter-totter or seesaw type for a plurality of riders which are characterized by completely individual movement of each rider wherein movement of any one rider does not affect the movement of any other riders. 
     It has been found by this invention that the above object may be accomplished by providing playground apparatus, generally as follows. 
     A generally vertically disposed support means is provided. A plurality of spaced-apart rocker arms having an inner end and an outer end extend generally radially outwardly from said support means. Separate pivot means individually connect the inner end of each of the rocker arms to the support means, without interconnection to the other of the rocker arms, for individual pivotal up and down movement of each of the rocker arms. Separate resilient biasing means are provided for each of the rocker arms for individually biasing each of the rocker arms in an upward direction and for allowing downward movement of each of the rocker arms against the bias thereof. A rider supporting unit is provided on the outer end of each of the rocker arms. 
     Preferably, the biasing means comprises a coil spring device and further includes means for adjusting the biasing means to increase and/or decrease the biasing force thereof for different size and weight riders. 
     With the above broad constructional features of playground apparatus in accordance with this invention, a plurality of riders may individually support themselves on the supporting units and effect an independent up and down ride by moving the rocker arms individually about the separate pivot means with and against the bias of the separate biasing means without affecting the movement of the ride of other riders. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Some of the objects and advantages of this invention having been set forth, other objects and advantages will appear when taken in conjunction with the accompanying drawings, in which: 
     FIG. 1 is a perspective view of a first embodiment of playground apparatus in accordance with this invention; 
     FIG. 2 is a partially exploded, perspective view of the first embodiment of playground apparatus illustrated in FIG. 1; 
     FIG. 3 is a sectional view, taken generally along the line 3--3 of FIG. 1; 
     FIG. 4 is a sectional view, taken generally along the line 4--4 of FIG. 3; 
     FIG. 5 is a perspective view of a second embodiment of playground apparatus in accordance with this invention; and 
     FIG. 6 is a sectional view, taken generally along the line 6--6 of FIG. 5. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     In the accompanying drawings, there are illustrated two preferred embodiments of playground apparatuses 10, 10&#39; constructed in accordance with this invention; however, it is to be understood that other embodiments of playground apparatuses could be constructed utilizing the novel features of this invention. 
     Referring firstly to the first embodiment of playground apparatus 10, illustrated in FIGS. 1-4, this playground apparatus 10 comprises a generally vertically disposed support means 12. This support means 12 may comprise a base plate 13 secured by bolts or otherwise to the surface upon which the apparatus 10 is resting, such as a cement block embedded in the ground, as illustrated in FIGS. 1 and 2, if the apparatus 10 is located outdoors. The support means 12 may further include an upstanding post member 14 of generally square cross-sectional configuration having four oppositely disposed faces. The support means 12 may further include arms 15 of a generally upside down U-shape configuration extending radially outwardly from the top of the post member 14 and being spaced approximately 90° from each other. The support means 12 may further include a cover member 16 which may be of any desired shape for being placed over and substantially covering the above-described components of the support means 12 and may be bolted to the other components of the support means 12. 
     The playground apparatus 10 further includes a plurality of spaced-apart rocker arms 20 having an inner end 20a and an outer end 20b and extending generally radially outwardly from the support means 12. Preferably, the plurality of rocker arms 20 comprises at least two rocker arms spaced approximately equi-distant from each other and preferably four rocker arms spaced approximately 90° from each other, as illustrated in FIGS. 1, 2 and 4. However, it is to be understood that any number of rocker arms 20 may be utilized in accordance with this invention. In the embodiment of FIGS. 1-4, each rocker arm is generally L-shaped with the inner end portion 20a forming a first shorter leg and the outer end portion 20b forming a second longer leg which are disposed with respect to each other at an acute included angle. 
     The playground apparatus 10 further includes separate pivot means 25 for individually connecting the inner end 21 of each of the rocker arms 20 to the support means 12, without any interconnection to the other of the rocker arms 20, for individual pivotal up and down movement of each of the rocker arms 20. Each of these pivot means 25 may be in the form of a bolt and nut device, as shown particularly in FIG. 4, which passes through the arms 15 of the support means 12 and through the inner end 20a of the rocker arms 20 which may be received within the inverted U-shaped arms 15. 
     The playground apparatus 10 further includes separate resilient biasing means 30 for each of the rocker arms 20 for individually biasing each of the rocker arms in an upward direction and for allowing downward movement of each of the rocker arms against the bias thereof. 
     These resilient biasing means 30 are preferably in the form of a coil spring, as shown in FIGS. 2-4, extending between each of the rocker arms 20 and a stationary surface, such as a respective face of the upstanding post 14 of the support means 12, for compressing and elongating during the up and down movement of the rocker arms. 20. 
     Each of the biasing means 30 further preferably includes means for adjusting the biasing means 30 to increase and/or decrease the biasing force thereof for different size and weight riders. In the embodiment of playground apparatus 10 illustrated in FIGS. 1-4, this bias adjusting means comprises serially-arranged, spaced-apart, stud means 31,32 respectively on each of the rocker arms and on the stationary surface, i.e. the respective faces of the upstanding post member 14 of the support means 12, for receiving and positioning each of the coil spring biasing means 30 in a plurality of positions, two of which are illustrated in FIG. 3, for adjusting the biasing means 30 to increase and/or decrease the biasing force thereof for different size and weight riders. 
     As illustrated in the first embodiment of playground apparatus 10 in FIGS. 1-4, there are four serially arranged studs 31 on each of the faces of the upstanding post 14 of the support means 12 and four serially arranged studs 32 on the inner section 20a of each rocker arm 20 for receiving the coil spring biasing means 30 in any one of four positions so that the bias of the coil spring 30 exerted on the respective rocker arm 20 may be increased or decreased according to the chosen position. 
     The playground apparatus 10 preferably further includes stop means 35, in the form of a pin extending through the respective arms 15 of the support means 12 for abutment by the inner end portion 20a of each rocker arm 20 for limiting the upward movement of each respective rocker arm 20. 
     A rider supporting unit 40 is contained on each of the outer ends 20b of each rocker arm 20. This rider supporting unit 40 may be of any desired configuration, such as the seat and bar mechanism along with foot supports illustrated in the drawings for receiving and supporting a rider on the outer end 20b of each of the rocker arms 20. 
     With the above arrangement of playground apparatus 10 in accordance with this invention, a plurality of riders may individually support themselves on the supporting units 40 and effect an independent up and down ride by moving the respective rocker arm 20 individually about its separate pivot means 25 with and against the bias of the separate biasing means 30 without affecting the movement of the ride of other riders. This has not been accomplished with similar types of seesaw or teeter-totter playground apparatuses heretofore known inasmuch as the rocker arms of the prior playground apparatuses were all interconnected in some fashion to each other so that movement of one rider affects movement of another rider. 
     Referring now to the second embodiment of playground apparatus 10&#39; in accordance with this invention, illustrated in FIGS. 5 and 6, this playground apparatus 10&#39; utilizes all of the above-described constructional features of the first embodiment of playground apparatus 10 illustrated in FIGS. 1-4 and like reference numerals with prime notations have been applied to these structural features of the second embodiment of playground apparatus 10&#39; in FIGS. 5 and 6. 
     The differences in the apparatus 10&#39; of FIGS. 5 and 6 and the apparatus 10 of FIGS. 1-4 reside in the shape of the rocker arm 20&#39; with the inner portion 20a&#39; forming a first longer leg and the outer portion 20b&#39; forming a second shorter leg and which are disposed at generally an obtuse angle with respect to each other. Also, the coil spring biasing means 30&#39; extends between each rocker arm 20&#39; and a stationary surface, such as a concrete block upon which the apparatus 10&#39; rests. With this arrangement, the serially arranged, spaced-apart studs 31&#39;, 32&#39; will be arranged as illustrated in FIGS. 5 and 6. 
     These differences will not alter the operation of the playground apparatus 10&#39; over the playground apparatus 10 and are only illustrative of the different way of constructing playground apparatus in accordance with this invention. It is to be understood that other arrangements of playground apparatus could also be utilized taking advantage of the novel features of this invention. 
     In the drawings and specification, there have been set forth preferred embodiments of this invention and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation.