GB2075350A

GB2075350A - Playground making apparatus

Info

Publication number: GB2075350A
Application number: GB8114023A
Authority: GB
Original assignee: B Hirst and Sons Ltd
Current assignee: B Hirst and Sons Ltd
Priority date: 1980-05-09
Filing date: 1981-05-07
Publication date: 1981-11-18
Also published as: GB2075350B

Abstract

The apparatus comprises a seat assembly (body portion 12) pivotally connected to ground supports 14, such that a child riding thereon can rock the seat assembly to and fro, torsion joints being provided where pivotal links 16 are connected to body portion 12 and/or supports 14 in order to prevent dangerous rocking actions of the seat assembly at its limits of movement. The braking force provided by the torsion joints increases as the seat assembly moves towards said limits. <IMAGE>

Description

SPECIFICATION Playground apparatus The invention relates to playground apparatus and more particularly to apparatus having a seat assem bly which is arranged to be pivotally connected to at least one ground support rigidly secured to the ground, so that a child riding on the apparatus can rock the seat assembly to and fro. Such apparatus twill hereinafter be denoted by "rocking apparatus of the kind referred to".

Conventional rocking apparatus such as, for example, rocking horses and rocking boats, has a seat assembly which is pivotally connected at each of its ends to a connecting link, each link being itself pivotally connected to a respective ground support.

The arrangement is such that when a child mounts the conventional rocking apparatus and moves to and fro, the seat assembly is pivoted about each link, and each link is pivoted about the associated ground support with the result that the seat assembly pit ches and heaves relatively to the ground, one end of the seat assembly rising as the other end falls. Occa sionally, when the seat assembly has sufficient momentum, an end of the seat assembly will, near to the upper limit of its travel, rapidly reverse its direc tion of movement from an upward to a downward path. This latter jerky movement is potentially dangerous in that a child mounted on the apparatus could easily be thrown from or against the seat assembly as the said end of the seat assembly rapidly changes direction.

The present invention seeks to provide a rocking apparatus which is safer in use than conventional rocking apparatus.

According to the invention a rocking apparatus of the kind referred to includes a torsion joint con nected between the seat assembly and one ground support, the torsion joint being arranged to provide a braking force on movement of the seat assembly, which braking force increases as the seat assembly moves towards its limits of movement. This progres sively braking force exerted on the seat assembly damps the motion of the seat assembly particularly at the rearward and forward limits of movement thereof, so that the sudden and jerky movement experienced by conventional seat assemblies is avoided or at least substantially reduced. The brak ing force provided by the torsion joint depends upon the relative "stiffness" of that joint to the movement of the seat assembly relatively to the ground sup port.

Preferablythetorsion joint comprises inner and outer elements having one or more deformable elas homeric members located between them, the or each elastomeric member being adapted to be stressed by relative rotation between the inner and outer elements, wherein one of these elements is con nected to the seat assembly and the other of the elements is connected to the ground support.

The seat assembly may be connected to more than one ground support and a torsion joint may be con nected between the seat assembly and each ground support. A pivotal link may be pivotally connected between each ground support and the seat assembly, one end of each pivotal link being pivotally connected at a first connection point to a ground support and the other end of each link being pivotally connected at a second connection point to the seat assembly. A torsion joint may be arranged at any one, or at each of the first and/or second connection points to provide a braking force between one or more pivotal link(s) and the seat assembly and/or one or more ground supports. Thus, for example, a torsion joint may be arranged between each pivotal link and the seat assembly and/or between each pivotal link and each associated ground support.

The rocking apparatus may have a pair of pivotal links connected one at each end of the seat assembly, each pivotal link being pivotally connected to, and supported on an associated ground support.

The torsion joint preferably comprises a torsion bearing and may have a pair of co-axial bearing collars having an elastomeric packing such as, natural or synthetic rubber secured therebetween so that relative rotation between the outer collar of the pair of collars and the inner collar of the pair of collars results in the packing being stressed, the resistance of the packing to deformation increasing with increase in the relative rotation of the outer and inner collars. Atorsional bearing can thus be arranged at one or more of the first connection point(s), one collar of each bearing being connected to a pivotal link, and the other collar thereof being connected to a ground support.Alternatively, or in addition a torsional bearing can be arranged at one or more of the second connection point(s), one collar of each bearing being connected to a pivotal link and the other collar thereof being connected to the seat assembly. The increasing resistance to deformation of the packing of the or each torsional bearing thus provides the increasing braking force on the seat assembly as the latter moves towards its forward and rearward limits of travel.

The ground support may comprise a bracket having one or more flanges. A pivotal link may be secured, for example, by means of one or more nut and bolt connections, to the or each flange of a bracket.

Each pivotal link may comprise an elongate arm having an eye socket formed at each end thereof, and a torsional bearing or other torsional joint may be located within one or more of the eye sockets of one or more ofthe pivotal links.

The invention also includes a method of adapting existing conventional rocking apparatus to rocking apparatus according to the invention, as described above, comprising providing a torsional joint such as a torsional bearing, between the seat assembly and one or more ground support(s) of a conventional rocking apparatus. Where the method comprises the provision of a torsional bearing as aforesaid, the torsional bearing may be substituted for another bearing of the conventional rocking apparatus.

For a better understanding of the invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is a side elevation in part-section of a rock ing horse; Figure 2 is a cross-sectional part view of the rocking horse taken on the line ll-ll of Figure 1; and Figure 3 is a view similar two Figure 2, but showing an alternative arrangement.

A rocking apparatus in the form of a rocking horse is indicated generally at 10 and comprises a body portion 12 and a pair of ground support brackets 14.

A pivot arm 16 is secured between each bracket 14 and the body portion 12, one bracket 14 being located near to a forward end 18 of the body portion and the other bracket 14 being spaced apart from the said one bracket and located near to the rearward end 20 of the body portion 12.

The body portion 12 is of a conventional form having a horse's head 20 secured to the upper surface 22 at the forward end 18 thereof. A series of metal seats 24 is secured in spaced-apart relationship to the upper surface 22 of the body portion 12 along the length thereof, and a hand grip rail 26 is formed on the rear upper end of each but the rear seat 24. A pair of hand grips 28 project outwardly one from each side of the head 20. The arrangement of the body portion 12 is such that a child (not shown) can sit in one of the seats 24 with its legs astride the body portion 12 and can grip one of rails 26, or the hand grips 28 positioned immediately in front of the child.

Afoot rest 30 in the form of a flat board is provided along the length of the lower part of the body portion 12 at each side thereof, so that a child seated on the body portion 12, as previously described, can support each of its feet on a corresponding one of the rests 30.

Each bracket 14 is U-shaped in cross-section having a web and two flanges, the flanges each extending substantially parallel to the longitudinal axis of the body portion 12, from the web. A pair of rails 32 is secured between the webs of each bracket 14 by means of nuts 34 threaded one on each end of each rail 32, the rails 32 being spaced-apart from each other vertically. The rails 32 ensure that the brackets 14 are rigidly maintained parallel with each other, the brackets 14 each depending substantially verticalls from an associated end of the body portion 12.

The lower portion of each bracket 14 and the lower of the rails 32 are rigidly located in the ground 36 by means of concrete 38 which is hardened around the lower end of each bracket to ensure that the brackets 14 do not move to any great extent (if at all) relatively to the ground 36. The brackets 14thus provide a rigid support on which the body portion 12 can rock to and fro on each pivot arm 16.

The pivot arms 16 each comprise a pairofcylindri- cal sockets 40, the sockets of each arm 16 being formed one at each end thereof. A spindle 42 is secured within each socket 40 by a taper pin and each end of each spindle 42 isjournalled in bearings. The upper spindle 42 of each socket is journalled in roller bearings 41 mounted on a fixing plate 44, each fixing plate 44 being bolted to the web of the U of an associated bracket 14 near to the top thereof. The lower spindle 42 of each socket is journalled in bearings 43 located in respective mounting housings 54 which are each secured by nuts and bolts 45 one to each foot rest 30 and side panel 46 of the body portion 12. The lower spindles 42 are also secured at each of their ends to an inner collar 48 of a torsion bearing 50.The torsion bearings 50 each comprise the inner collar 48 and an outer collar 52 co-axial with the inner collar 48, a rubber packing 49 being nipped between the inner and outer collars 48 and 52.

Each outer collar 52 is rigidly welded to the mounting housing 54 secured to an associated one of the foot rests 30 and side panels 46. The arrangement of each torsion bearing 50 is such that as the lower spindle 42 secured to the inner collar 48 thereof, is rotated, the inner collar 48 rotates. The outer collar 52 is prevented from rotating since it is rigidly secured to the housing 54 which itself is bolted to a foot rest 30 and side panel 46. As this relative rotation between the inner collar 48 and the outer collar 52 takes place, the rubber packing 49 therebetween is deformed, the resistance to deformation thereof increasing with increase in the relative rotation between the collars 48 and 52. The resistance to deformation of the rubber packing 49 of each torsion bearing 50 provides a braking effect on the rotation of each housing 54 relatively to the associated lower spindle 42.The oscillatory motion of the rocking horse loins thus damped by means ofthetorsion bearings 50.

As seen clearly in Figure 1, the pivotal arms 16 are opposed to each other so that when a child is seated on the rocking horse 10, as previously described, and rocks back and forth on the body portion 12, the forward and rearward arms 16 are pivoted so that the rocking horse 10 oscillates to and fro the forward end 18 of the rocking horse being lowered as the rearward end 20 is raised and vice versa. This latter arrangement is conventional, but in conventional rocking horses, quite often near to the upper limit of travel, one or other of the ends of the body portion 12 will suddenly change direction producing a bucking action of the body portion which is potentially dangerous in that a child seated on the rocking horse could be thrown therefrom or against the horse as it bucks.The present invention ensures that the horse 10 will not buck since the torsion bearings 50 progressively apply a braking force to the lower end of each arm 16 so that the pivot arms 16 are restricted in the extent to which they are able to pivot relatively to their associated housings 54. It is intended that the rubber packing material 49 shall be of sufficient resistance to deformation to ensure that the braking effect caused by the provision of the torsion bearings 50 at the lower end of each arm 16, is sufficient to prevent the bucking action of the body portion'12.

The rocking horse 10 of the invention is thus less dangerous than conventional rocking horses since it is restricted in the limits of its movement by the torsion bearings 50 so that the bucking action apparent in conventional rocking horses is obviated It will be appreciated that alternr dve embodiments according to the inventior jre also envisaged.

Thus, for example, the invention could be applied to other rocking apparatus such as for example a rocking boat. Also, it will be appreciated that an existing rocking apparatus can be converted to a similar apparatus within the scope of the invention by the provision of a torsion bearing 50 or othertorsion joint acting between the body portion and the ground supports (the brackets 14) of the apparatus.

The torsion bearing 50 could be of any desired size, and could if required be replaced by some other torsional joint. Also, one or more ofthe upper spindles 42 could alternatively, or in addition be each journalledin a torsion bearing 50 or other torsion joint. It will be understood that sufficient braking effect could in some instances, be achieved by providing a torsion bearing 50 at each side of only one of the lower and/or upper spindles 42 and this is also envisaged as a further possible embodiment according to the invention.

In the variant shown in Figure 3, each lower spindle 42 is journalled in a pair of respective roller bearings 41, whilst each upper spindle 42 is journalled in a pair of respective torsion bearings 50. This arrangement may be particularly advantageous, in that the situation of the torsion bearings 50 around the upper spindles 42 may have a more positive limiting action on movement of the body 12, whilst provision of the roller bearings 41 around the lower spindles 42 may facilitate starting of the rocking action, from rest.

As may be seen in Figure 3, each arm 16 is keyed to the upper and lower spindles 42 by means of respective taper pins 64 which pass through registering apertures in the arm 16 and spindles 42. The lower roller bearings 41 are secured in downwardly extending portions of fixing plates 66 secured to the foot rests 30 and side panels 46.

Each torsion bearing 50 is mounted by an interference fit in a respective aperture formed in a respective one of the fixing plates 44. To secure the outer collar 52 firmly against rotation relative to the fixing plate 44 (which may be a casting and therefore sub jest to appreciable tolerances), a respective hard steel collar 65 is hammered down around each outer collar 52, to ensure a very tight interference fit therewith, and is secured to the respective fixing plate 44 by three securing bolts 61. For additional security against rotation, a respective Allen screw 62 or the like threadedly engages each steel collar 65, and abuts against the outer collar 52 of the respective torsion bearing 50. Preferably, the outer collar 52 is formed with an indentation, for example in the form of a dimple, to receive the Allen screw 62.

It may be seen that the inner collar 48 of each torsion bearing 50 projects inwardly thereof, and is keyed to the respective upper shaft 42 by means of a pin 63 which passes through registering holes in the inner collar48 and the upper spindle 42.

It may be appreciated that the position of the arms 16 relative to their respective torsion bearings 50 is important, to ensure correct functioning of the apparatus. Thus, a preferred method of assembly is to place each arm 16 in a position corresponding to the neutral position of the body 12 (i.e. the body 12 then being completely horizontal), whereafter the respective upper spindle 42 (then being keyed to the arm 16) is drilled with apertures registering with those in the inner collars 48. For example, for convenience, such apertures may be drilled in a truly vertical position. An alternative method of fixing is to key together the arm 16, the upper spindle 42 and inner collars 48 of the torsion bearings 50, which in this case are not a tight interference fit in the fixing plates 44. The arm 16 is then placed in its neutral position, whereupon the torsion bearings 50 are rotated to their corresponding neutral positions in the fixing plates 44. The steel collars 65 are then hammered down tightly around the outer collars 52 of the torsion bearings 50, and secured to the fixing plates 44 by means of the securing bolts 61, to locate the torsion bearings 50 positively in their desired positions.

In addition to providing enhanced performance, the arrangement illustrated in Figure 3 affords the further advantage that the torsion bearings 50 are better protected from weather, being concealed within the body 12.

Claims

1. Rocking apparatus of the kind referred to, including a torsion joint connected between the seat assembly and one ground support, the torsion joint being arranged to provide a braking force on movement of the seat assembly, which braking force increases as the seat assembly moves towards its limits of movement.

2. Rocking apparatus according to Claim 1, wherein the torsion joint comprises inner and outer elements connected one to the seat assembly and the other to the ground support, and one or more deformable elastomeric members located between said elements such that the elastomeric member is adapted to be stressed by relative rotation therebetween.

3. Rocking apparatus according to Claim 1 or2, wherein the seat assembly is connected to more than one ground support, and a respective said torsion joint is connected between the seat assembly and each ground support.

4. Rocking apparatus according to Claim 3, wherein the seat assembly is connected to two ground supports at or adjacent opposite respective ends of the seat assembly.

5. Rocking apparatus according to any preceding claim, wherein the seat assembly is connected to the or each ground support by a respective pivotal link which is pivotally connected to the ground support and seat assembly at first and second connection points respectively.

6. Rocking apparatus according to Claim 5, wherein a respective said torsion joint is provided at the or each first connection point.

7. Rocking apparatus according to Claim 5 or 6, wherein a respective said torsion joint is provided at the or each second connection point.

8. Rocking apparatus according to Claim 5, wherein a respective said torsion joint is provided at the or each second connection point and a respective roller bearing is provided at the or each first connection point.

9. Rocking apparatus according to Claim 2 or any one of Claims 3 to 8 as appendant thereto, wherein the or each torsion joint cmprises a torsion bearing in which said inner and outer elements comprise inner and outer collars respectively, and said elastomeric member comprises an annular packing dis posed between the collars.

10. Rocking apparatus according to Claim 9, wherein said packing is of natural or synthetic rub ber.

11. Rocking apparatus according to Claim 5 or any one of Claims 6 to 10 as appendant thereto, wherein the or each pivotal link comprises an elongate arm having a respective eye socket formed at each of two opposite ends thereof.

12. Rocking apparatus according to Claim 11, wherein each end of each said arm is secured to a ;,respective spindle passing through the respective ;eye socket, which spindle is journalled in a pair of bearings, each at or adjacent a respective end thereof. -

13. Rocking apparatus according to Claim 12 as appendant to Claim 9whernin the or each said inner collar projects longitudinally of the respective torsion bearing and is secured to a respective one of the spindles.

14. Rocking apparatus according to Claim 13, wherein the or each said inner collar is secured to its respective spindle by a pin passing through registering holes in the collar and spindle.

15. Rocking apparatus according to Claim 19 or any one of Claims 10 to 14 as appendant thereto, wherein the or each said outer collar is secured by an interference fit in an aperture formed in a part of, or a part fixed to, said seat assembly or ground support.

16. Rocking apparatus according to Claim 15, wherein the or each said outer collar is also secured by an interference fit in a steel collar which is secured to the respective said part.

17. Rocking apparatus according to Claim 15 or 16, wherein respective securing means is provided for positively engaging the or each said outer collar to prevent rotation thereof with respect to the respective said part.

18. Rocking apparatus according to Claims 16 and 17, wherein the or each said securing means comprises a respective Allen screw or the like retained in the respective said steel collar and engaging the respective said outer collar.

19. Rocking apparatus according to Claim 18, wherein the or each said outer collar is formed with a recess to receive the respective said Allen screw or the like.

20. Rocking apparatus of the kind referred to and substantially as hereinbefore described with reference to Figures 1 and 2 or Figures 1 and 3 of the accompanying drawings.

21. A method of modifying the rocking apparatus of the kind referred to, comprising the steps of pro .viding a torsion joint between the seat assembly and one ground support, the torsion joint being arranged to provide a braking force on movement of the seat assembly, which braking force increases as the said assembly moves towards its limits of movement.

22. A method according to Claim 21, wherein the rocking apparatus is modified to provide rocking apparatus according to any one of Claims 2 to 20.

23. A method according to Claim 21 or 22, wherein the or each torsion joint is a torsion bearing, and the method includes the step of substituting the or each torsion bearing for an existing bearing of the rocking apparatus.