US 3276544 A
Description (OCR text may contain errors)
Oct. 4, 1966 Filed May 18, 1965 N. S. HALL.
TRAMPOLINES FIG. 3
5 Sheets-Sheet 1 Oct. 4, 1966 N. s. HALL 3,276,544
TRAMPOLINES Filed May 18. 1965 5 Sheets-Sheet 5 INK/EN t United States Patent 3,276,544 TRAMPOLINES Nevil Siemers Hall, Flat 21, Highlands, 14 Eezuidenhout St., Johannesburg, Transvaal, Republic of South Africa Filed May 18, 1965, Ser. No. 456,758 Claims priority, application Republic of outh Africa, Aug. 13, 1964, 2,236/64 2 Claims. (Cl. 182--139) This invention relates to trampolines.
Trampolines are generally formed as Open frame structures having mats secured within the frames by means of resilient elements in the form of coiled tension springs or strong rubber or like bands stretched between the frame and mat. The frames are either supported on suitable legs or located over an open pit.
It is very often necessary, particularly when such trampolines are located out of doors, to remove the mat and resilient elements from the frame when the apparatus is not in use to prevent theft or avoid the deleterious effects of exposure on the mats and resilient elements.
This removal and re-attachment very often results in stretching of the resilient elements and even where periodical removal of the mat is not necessary, the sustained tension in the mat and resilient elements may damage these components and reduce the efiiiciency of the trampoline.
Apart from this the removal, attachment or replacement of each individual resilient element is a tedious and time consuming operation.
A known folding frame type of trampoline serves to reduce the tension of the resilient elements extending in one direction when the frame is folded but the remaining elements extending in line with the fold remain under full tension.
Also no types of trampolines known to applicant have provision for adjusting the tension of the resilient elements to compensate for stretching of these elements.
It is accordingly an object of this invention to provide a trampoline frame wherein the tension of most or all of the resilient elements can readily be varied and which will facilitate removal and attachment of the mat to the frame.
It is a further object of the invention to provide a folding type of trampoline embodying the above and additional advantageous features.
According to this invention there is provided a trampoline frame comprising a pair of side and a pair of end members connected to form a generally rectangular open structure, a plurality of anchor means embodied in each member for securing resilient mat supporting elements thereto, the anchor means in at least one side and one end member being movable relative to the anchor means in the opposite side and end members respectively, while a mat is secured in the frame by the said resilient elements.
A further feature of the invention provides for at least one side and one end member to be rotatable in relation to the remainder of the frame and for at least one side member to comprise hinged sections rotatable in unison when axially aligned.
Additional features of this invention will become ap parent from a description of one illustrative embodiment thereof with reference to the accompanying drawings in which:
FIG. I is an elevation of a folding trampoline,
FIG. 2 is a plan of FIG. 1,
FIG. 3 to are details,
FIG. 6 illustrates the method of attachment of the resilient mat supporting elements to the frame members,
FIG. 7 is an alternative form of hinge for the trampoline frame and FIG. 8 is an elevation of the trampoline frame in the semi-folded condition.
Broadly, as shown in the drawings the frame 1 comprises a pair of straight tubular side members 2 connected to the ends of a pair of U-shaped tubular end members 3 the centre portions 3A of which are also straight. The side members 2 are rotatable about their own axes, and each consists of three sections 2A, 2B, and 2C connected together by hinges 4, 5 the arrangement being such that all three sections 2A, 2B and 2C and the corresponding hinges 4, 5 can rotate in unison when the sections are axially aligned.
The centre portions 3A of the U-shaped end members 3 are also rotatable and in both members 3 this is achieved by fitting the rotatable portions 3A over spigots as more fully described hereinafter.
The frame carries a mat 6 secured by means of resilient mat supporting elements 7 attached to the mat 6 and anchored to perforations 8 in the rotatable portions of the frame as is more clearly illustrated in FIG. 6.
Thus, rotation of the rotatable portions of the frame will increase or decrease the tension in the resilient elements 7 and the mat 6.
The frame 1 is supported on U'shaped legs 9 secured to the side members 2 by means of sleeves 10 to allow rotation of the side members 2 while supported on the legs 9.
Rotation of each side member 2 is effected by a lever 11 attached to the corresponding side member 2 by means of a cylindrical clamp 12 the lever if being adapted to engage a stop 13 on the legs 9.
Bracing stays 1d extend from the end members 3 are removably attached to the legs 9.
Conveniently, the bracing stays I l serve the dual purpose of stays as well as levers for effecting rotation of the rotatable centre portions 3A of the end members 3. For this reason the stays T4 are adjustably secured to these rotatable portions 3A, so that the tension of the mat 6 may be varied with the stays 14 in the same operative position.
As shown in the drawings the two sides 2 of the frame 1 are formed from two equal lengths of tubing which are rotatably fitted onto the two U-shaped end members 3 of the frame 1, the side members 2 and end members 3 being of equal diameter. This is conveniently achieved by securing short lengths of tubing in the ends of the arms of the U-shaped end members 3 to form projecting spigots 15 over which the ends of the two side members 2 are rotatably fitted with the ends of the side members 2 and end members 3 abutting or closely adjacent as is illustrated in FIG. 3.
With this construction the diameter of the frame 1 at any point is the same so that there are no undesirable projections.
The end sections 2A and 20 of side members 2 adjacent the hinges i, 5 are formed as separate sleeves it} rotatable on spigots 17 secured to and projecting from the bores of section 2A and 2C. The projecting portions of spigots 17 are slightly longer than the lengths of sleeves 10 as is shown in FIG. 4.
The leaves 18 of hinges 5 are welded or otherwise secured to the end of the spigots 17 so that the leaves 18 project radially outwardly of the spigots 17 to form stops for sleeves 10, with the axes of the hinge pins 19 located transversely to the axes of the spigots 17.
The other leaf 20 of each hinge 5 is welded or otherwise secured to the centre section 23 of each side member 2 so that when the inner faces of the hinge leaves 18 and 29 abut all three sections 2A, 2B, 2(1 of the side m-em bers 2 are axially aligned.
The portions of the hinge leaves 18, Zil opposite the and hinge pins are cut away to correspond to the shape of the tubing of the frame 1 wherever possible.
The hinges 4 are located in a similar manner between sections 2A and 2B of each side member 2.
The hinge leaves of the hinges 4 are, however, of such a length that the corresponding hinge pins 19 are located a distance from the outer periphery of the tubing approximately equal to or greater than the diameter of the said tubing, so that these hinges 4 are longer than the hinges 5.
Alternatively, all the hinges may be in the form illustrated in FIG. 7 with the members 21 connecting the two lengths of tubing made of different lengths for opposite ends of the frame.
The leg supports 9 are of substantially U-shape, the ends of each support 9 being pivotally secured to lugs 22, which project from sleeves 10.
The supports 9 can accordingly fold to lie closely adjacent correspondingly shaped end members 3 of the frame 1 but are normally held at an angle of approximately 45 to the frame by means of the bracing stays 14 which are secured to the centre portions 3A of the frame 1 and removably engage the supports 9.
The free ends of the bracing stays 14 are provided with hook formations 23 adapted to engage the portions of the 'U-shaped supports 9 which extend transverse to the length of the frame as shown in FIG. 5. A locking pin 24 is carried in the stay 14 so as to be movable axially therein and the pin 24 serves to lock the end of the stay 14 to the support 9. Any other convenient form of bracing and removable lock arrangement may, however, be employed.
A single length of chain 25 (see FIG. 1) is passed over each corresponding leg of the opposite supports 9 so that the chains 25 lie towards the lower ends thereof. The U-shaped support 9 at one end of the frame has stops 26 for preventing the chain 25 from moving up or down in relation to the legs although it can be freely threaded through the stops 26 and the other U-shaped support has similar stops 27 at corresponding positions but from which the chain 25 can be removed.
Initially the chains 25 are passed through stops 26 and under stop 27 and tautened, preferably by means of a turnbuckle 28 incorporated in the length of each chain 25, so that even with the bracing stays 14 removed, the chains 25 maintain the supports 9 substantially in the operative position. When it is desired to fold the supports 9, the chains 25 are lifted over the one set of stops 27, and, as the one or other set of supports 9 are folded, the chains 25 are allowed to slide up the supports 9 towards the hinges 5.
The effect of this would be that the chains 25 are always maintained in a comparatively taut condition.
The supports 9 or chains 25 will preferably be provided with a protective sheath of resilient material (not shown) such as rubber or a synthetic resin where the chains 25 are likely to rub. The supports 9 may also be provided with similar sheaths 29 at their lower extremities to serve as feet for the apparatus.
The rotatable tubular members of the frame 1 are perforated at intervals (see FIG. 6) so that with the hinge leaves of hinges 4 and projecting downwardly, the perforations 8 in the sides 2 and end members 3 of the frame 1 are directed towards the inside of the frame 1.
The resilient mat supporting elements in this example are lengths of rubber bands '7 folded double and having wire hooks 30 secured to their free ends. The opposite ends of the rubber bands are secured to the edges of the trampoline mat 6 at spaced intervals corresponding to the intervals between the perforations 8 in the frame 1.
The mat 6 is secured within the frame 1 by rotating the side members 2 of the frame so that the perforations 8 are located at the outside of these members and the rubber bands 7 are passed over these members and the hooks .30 passed through the perforations 8.
It will be appreciated that with the perforations 8 located at the outside of the side members 2 of the frame the leaves of the hinges 4, 5 of these members project upwardly.
The lever arm 11, having a handle 31, is used as a locking mechanism for preventing rotation of the side members and is pivotally secured to the lug 32 welded or otherwise secured to both side members 2 of the frame 1 by means of the cylindrical clamps 12. A stop 13 is provided on two opposite legs of the one support 9 and these stops are shaped so that the lever arm 11 may be engaged therein to prevent rotation of the side members 2. In the locked position the leaves of the hinges 4, 5 project downwardly so that in order to secure the side members 2 against rotation it is necessary to rotate the side members and this is facilitated by means of the lever arm 11.
This rotation of the side members 2 and perforations 8 through approximately serves to tension the resilient elements 7 which are of a length that will ensure that in this position they are sufficiently tensioned while in the unsecured position of the side members 2 the hooks 30 can be inserted into the perforations 8 without difficulty.
However, since this movement between the two positions of the rotatable side members 2 may not be correct once the resilient elements have stretched or for any other reason, the angular disposition of each lever arm 11 is made adjustable relative to the side members 2 by means of the cylindrical clamps 12 which may be secured in an appropriate position relative to the side members 2.
With the mat 6 secured within the frame 1 and with the frame erected, the tension in the resilient elements 7 tends to maintain the frame 1 in the erected condition since the hinge pins of hinges 4 and 5 are located below the centre of the frame.
To fold the apparatus both lever arms 11 are released from the stops 13 of the supports 9 and allowed to rotate upwardly under action of the resilient elements 7 so that hinge pins 19 of hinges 4, 5 are above the frame. The bracing stay 14 on the end of the frame nearest the shorter hinges 5 is then disengaged from the corresponding U-shaped supports 9 which is then folded flush against the frame section 2C which latter is then folded over centre section 2B (see FIG. 8). The same procedure is then followed with the other support 9 which, by virtue of the longer hinge 4, may be folded together with section 2A over the previously folded portion of the assembly.
Since the hinges should project vertically to permit the sections of the frame to fold, stops (not shown) may be located to arrest rotation of the side members 2 when the hinges arrive at the correct position.
As described above the chain 25 around one leg of each support 9 is removed from the stops 27 before folding either support 9.
The apparatus is thus folded into a neat assembly which is easy to transport and requires little storage space and the mat 6 and resilient elements 7 are relieved of tension in this condition.
To erect the apparatus for use the reverse procedure is followed.
It will be appreciated that the rotating side members 2 of the frame 1 do not form the only adjustable resilient element locating means since adjustment of the position of bracing stays 14 relative to sections 3A provides for adjustment of the operative tension of the resilient elements at the ends of the frame.
The tension in the end resilient elements 7 is, however, released when disengaging the stays 14 from the supports 9 and swinging the stays outwardly to lie in line with the length of and within the frame.
It is advantageous to extend the length of pipe of reduced diameter forming the supporting spigots 15 for the side members 2 around the bends to form similar spigots for the rotating end members 3A and in this Way strengthen the frame at the bends.
It will be appreciated that various modifications may be made to the example above described without departing from the scope of the invention and while the invention has been described as applied to a folding frame the use of rotatable framing members for varying the tension of the resilient elements could also be applied to a rigid trampoline frame structure.
What I claim as new and desire to secure by Letters Patent is:
1. A trampoline comprising a generally rectangular open structure, end members and oppositely disposed assemblies of side sections forming part of said structure, hinges connecting said side sections together, mountings for the end members allowing rotation thereof about their own axes, mountings for the assemblies of side sections allowing rotation of each assembly with the sections forming each assembly axially aligned, a pair of sleeves on each assembly of side sections, supporting legs secured to said sleeves, braces rigidly secured to said end members and projecting generally radially therefrom, means for detachably securing the braces to the legs and anchor means embodied in the end members and side sections.
2. A trampoline in accordance with claim 1 including a locking arm hinged to a side section of each assembly and a step on the corresponding legs detachably engageable by the locking arm.
References Cited by the Examiner UNITED STATES PATENTS 952,871 3/1910 Browder 182139 2,430,714 11/1947 Geer 182139 2,809,383 10/1957 Fenner 182-439 2,858,551 11/1958 Sidlinger 182-139 3,226,861 1/1966 Bird 160-378 20 REINALDO P. MACHADO, Primary Examiner.