Waterbeds

Abstract: A waterbed mattress comprises walls (12,13,14,16) of film material defining a chamber for holding water, a cornerpiece (21) substantially thicker and tougher than the film material joined to the film material and forming a corner of the mattress, an insert (19) disposed in the chamber for reducing wave action in the water, and a tether (27) connected between the insert (19) and the cornerpiece (21) to retain the insert in a predetermined position in the chamber.

Description: This invention pertains generally to waterbeds and, more particularly, to a waterbed mattress having an insert for reducing wave motion in the water within the mattress. Heretofore, a number of different internal structures or inserts have been employed in waterbed mattresses in an effort to eliminate, or at least reduce, the wave motion which some people find disturbing. Some early efforts involved the use of vertically extending baffles which were connected to the upper wall of the mattress and produced an undesirable pulling or tensioning of the sleeping surface. In other mattresses, horizontally extending baffles are connected to the bottom and/or side walls, but not to the top walls. The connections between the baffle structure and the walls of a mattress are generally made by heat sealing or welding, and such connections can fail and result in leakage. A mattress with an insert or baffle surface of this kind is shown e.g. in US-A- 4 345 348. Some waterbed mattresses have been provided with baffle structures or masses of fiber which float freely within the mattresses and are not attached to the mattress walls. Such mattresses overcome the problems which arise when the insert is attached to the bladder or bag, but they are subject to other problems. The loose insert can slide around inside the mattress, and once out of position, it can be difficult to restore to the proper position. The problem frequently arises when a mattress which has been filled with water must be moved. In order to move the mattress, it is generally necessary to drain the water from it. Typically, however, not all of the water drains out, and when one side or end of the partially drained mattress is raised, e.g., to roll or fold the mattress, the baffles or fibers slide toward the opposite side or end. This problem is particularly troublesome with fibers because they tend to form into a wet mass or ball which is difficult to smooth out when the mattress is refilled. Another problem with waterbed mattresses of the prior art is vulnerability to puncturing by sharp objects such as metal fasteners which hold the frame of the bed together at the corners. It is in general an object of the invention to provide a new and improved waterbed mattress and corner structure which overcome the limitations and disadvantages of mattresses heretofore provided. Another object of the invention is to provide a waterbed mattress and corner structure of the above character in which an insert is retained in position within the mattress without connection to the top, bottom or side walls of the bladder or bag. These and other objects are achieved in accordance with the invention by providing a waterbed mattress comprising walls of film material defining a chamber for holding water, a cornerpiece which is substantially thicker and tougher than the film material joined to the film material and forming a corner of the mattress, an insert disposed in the chamber for reducing wave action in the water, and a tether connected between the insert and the cornerpiece to retain the insert in a predetermined position in the chamber. Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a horizontal sectional view of one embodiment of a waterbed mattress incorporating the invention. Figure 2 is a cross-sectional view taken along line 2-2 in Figure 1. Figure 3 is a rear elevational view of one embodiment of a corner structure for a waterbed mattress according to the invention. Figure 4 is a cross-sectional view taken along line 4-4 in Figure 3. Figure 5 is a cross-sectional view taken along line 5-5 in Figure 3. Figures 6-8 are fragmentary isometric views of additional embodiments of waterbed mattresses incorporating the invention. Figure 9 is an isometric view, partly broken away, of a portion of another embodiment of a waterbed incorporating the invention. Figure 10 is an isometric view of an embodiment of an eyelet for use in a waterbed mattress in accordance with the invention. Figure 11 is an exploded isometric view of another embodiment of a waterbed mattress incorporating the invention. In Figures 1-2, the invention is illustrated in conjunction with a waterbed mattress 11 having generally rectangular top and bottom walls 12, 13, end walls 14 and side walls 16 which define a chamber 17 for holding a body of water (not shown). The walls are fabricated of a flexible, substantially inelastic material such as water impervious plastic film, e.g. 20 mil polyvinylchloride. An insert 19 is disposed in chamber 17 to reduce the wavelike motion of the water in the mattress. This insert can be of any suitable design, e.g. baffles or a fiber matt, which is not attached to the walls of the chamber. Cornerpieces 21 are sealed to the top, bottom, end and side walls to form the four corners of the mattress. These cornerpieces have a base plate 22 with relatively heavy ridges in the form of cleats 23, beads 24 and raised lettering (not shown) projecting from the front side thereof. The cleats, beads and raised lettering provide protection against punctures, as well as resistance to abrasion, and they also engage the bedsheets which are wrapped or tucked around the corners and thus help to retain the sheets in place on the mattress. Means are provided for holding the insert 19 in a predetermined position in chamber 17. These means comprise eyelets 26 which project from the rear side of base plate 22 and tether straps 27 which extend between the cornerpieces and the corners of insert 19. Each of the eyelets includes a ring 28 with an opening 29 through which the strap passes, with the eyelets thus forming anchor points for the straps. In the embodiment of Figures 3-5, each cornerpiece has two eyelets which are spaced vertically apart, with the rings 28 which form the eyelets lying in a common vertical plane and the openings 29 extending horizontally. Depending upon the type of insert, the tether strap can be attached to either the upper eyelet or the lower eyelet, or both. With a more buoyant insert, for example, the strap can be affixed to the lower eyelet to help hold the insert down, whereas a less buoyant insert might be tethered to the upper eyelet to help keep it afloat. The base plate, eyelet rings, cleats, beads and raised lettering are all formed as a monolithic structure by a suitable process such as injection molding. This process provides a rugged solid structure and is preferred to other processes such as vacuum forming or pressure forming which would produce an embossed effect with indentations in the rear surface behind the raised lettering and other protuberances on the front side of the base plate. The cornerpiece is preferably fabricated of a material which can be affixed to the walls of the mattress by heat sealing, is pliant enough to conform to the contour of the mattress and is tough enough to resist puncturing. The cornerpiece is generally fabricated of the same type of material as the rest of the mattress, and in a vinyl mattress, for example, the cornerpiece is fabricated of vinyl. The cornerpiece has a heavy construction which provides good protection against puncturing, maintains the integrity of the eyelets, and also provides a good grip on the bedsheets, as well as being aesthetically pleasing. In one presently preferred embodiment, the corner piece has a length on the order of 8-1/2 inches, a width on the order of 3-1/4 inches and a thickness on the order of .050 inch, with cleats 23 projecting about .110 inch along their outer edges, beads 24 projecting about .050 inch, and the raised lettering (not shown) projecting about .040 inch from the surface of the base plate. In this particular embodiment, the eyelet openings have a diameter on the order of 0.50 inch, and the rings which form the openings have a thickness on the order of .375 inch at the base and .15 inch near the outer end. While .050 inch is currently a preferred thickness for the base plate, the base plate can have a thickness on the order of .020 to .080 inch for a mattress having a walls of 20 mil vinyl, and the other dimensions of the cornerpiece can vary accordingly. The tether straps 27 can be of any suitable type, and three examples of suitable straps are illustrated in Figures 6-8. In the embodiment of Figure 6, each of the tether straps comprises an elongated strap 31 of suitable material, such as vinyl, which is looped through an opening 32 in insert 19 and through the upper eyelet opening 29 in one of the cornerpieces, with the end portions of the strap being knotted together as indicated at 33. In the embodiment of Figure 7, each of the tether straps comprises a plastic tie strip 36 of the type employed for bundling electrical wires and other items together. The tie strip is looped through an opening 37 in the insert and through the lower eyelet opening 29 in one of the cornerpieces, with the end portions of the strip being secured together by a fastener 38 which is formed as an integral part of the strip. In the embodiment of Figure 8, the tether strap comprises a strap 41 of suitable material such as vinyl which passes through an opening 42 in the insert and through the two openings 29 in one of the cornerpieces. Retainers 43 are attached to the two ends of the strap and are adapted to pass through the eyelets relatively freely in a forward direction but not in a reverse direction. In the embodiment illustrated, each of the retainers has a truncated conical shape with a tip diameter smaller than the eyelet openings and a base diameter larger than the eyelet openings, with either the retainer or the eyelet being deformable to permit the retainer to pass through the opening in the forward direction but not in the reverse direction. Thus, once inserted into the eyelets, the end portions of the strap are retained there by the retainers. In addition to keeping the wave reducing insert in position when the mattress is being drained and/or moved, the tether straps can also function as a part of the wave reducing structure. With a relatively thin layer of fibers, for example, the straps can be made short enough to maintain the fibers in tension and keep them afloat during normal use of the mattress. In applications where the straps do not need to support the insert structure, they can be long enough to be relaxed in normal use, coming into tension only when the insert structure starts to shift. Figure 9 illustrates the invention in connection with an elongated tubular bladder 46 for use in a waterbed having a plurality of such tubular bladders positioned side-by-side to form a water mattress. This bladder has a tubular side wall 47 and a pair of end panels 48. The side wall is fabricated of a flexible, substantially inelastic material such as plastic film, e.g., 20 mil polyvinylchloride, and the end panels are fabricated of a material which can be sealed to the side wall. Like the cornerpieces of the previous embodiments, the end panels have inwardly projecting eyelets 49 with openings 51 for receiving tether straps, and external ribs or beads 52 which help to hold the bedsheets in place. The end panels are formed as a monolithic structure by a suitable process such as injection molding, and they are preferably fabricated of a material which can be affixed to the side wall of the bladder by heat sealing and is tough enough to resist puncturing. With a vinyl side wall, for example, the end panels can be fabricated of polyvinylchloride. The side wall and end panels form a chamber 54 which holds a body of water 56. To reduce wave action in the water, a horizontally extending fiber insert 57 is placed in the chamber and retained in position by tether straps 58 which pass through the openings 51 in eyelets 49. The length of the straps, and hence the tension in them, is adjusted in accordance with the degree of support desired for the insert. Figure 10 illustrates an embodiment of an eyelet 59 which can be affixed to any wall of a waterbed mattress or bladder to provide an anchor point for a wave-reducing insert. This eyelet has a generally circular base 61 and a ring 62 which extends from the front side of the base, with an opening 63 in the ring for receiving a tether strap. The back side of the base is adapted to be affixed to the inside wall of the mattress or bladder by suitable means such as heat sealing or a suitable adhesive. Eyelet 59 is preferably formed as a monolithic structure by a suitable process such as injection molding, and it fabricated of a material which can be affixed to a wall of the mattress. With a vinyl mattress, for example, the eyelet can be fabricated of polyvinylchloride. Figure 11 shows another embodiment of the invention in which an insert 72 is tethered to the cornerpiece or base 69 affixed to a wall of a waterbed mattress or bladder by means of angled connector having straight portions 66,67 and 71, one end of the connector having a "T" shape 73 which secures the connector to one of two eyelets 68, in the base 69, the other end of the connector being itself in the form of an eyelet 74 and being secured to the insert 72 by means of a double-headed pin 76 which passes through a corner of the insert 72. The shape of the connector enables the insert 72 to be positioned in a desired location relative to the mattress walls, or to other inserts in the mattress. In mattresses where the tether straps are relaxed and free of tension during normal use, an eyelet for anchoring the tether straps can be made by forming a strip of material such as vinyl into a loop and heat sealing it to a wall of the mattress. With the straps relaxed, there is no stress or pull on the heat sealed area to cause a failure or leakage at this point. The invention has a number of important features and advantages. The wave controlling insert is held securely in place without any connection to the film material which forms the walls of the bag or bladder. With the insert tethered in this manner, the mattress can be drained, moved and reinstalled without any shifting of the insert within the mattress. Even a fiber mat will remain in place and will be smooth and ready to use when the mattress is refilled. In addition, the straps can function as part of the wave reducing structure, e.g. by maintaining a relatively light mat or sheet in tension. It is apparent from the foregoing that a new and improved waterbed mattress and corner structure have been provided. While only certain presently preferred embodiments have been described in detail, as will be apparent to those familiar with the art, certain changes and modifications can be made without departing from the scope of the invention as defined by the following claims.

Claims: A waterbed mattress comprising walls (12,13,14,16) of film material defining a chamber for holding water, a cornerpiece (21) which is thicker and tougher than the film material joined to the film material and forming a corner of the mattress, an insert (19) disposed in the chamber for reducing wave action in the water, and a tether (27) connected between the insert and the cornerpiece to retain the insert in a predetermined position in the chamber. A waterbed mattress as claimed in Claim 1 wherein the cornerpiece has an eyelet (26) on the inner side thereof through which the tether passes. A waterbed mattress as claimed in Claim 2 wherein the cornerpiece (21) and the eyelet (26) are formed as a unitary structure by injection molding. A waterbed mattress as claimed in any one of the preceding claims wherein the tether (27) comprises a strap which is normally in a relaxed condition when the insert is in the predetermined position. A waterbed mattress as claimed in any one of the preceding claims wherein the tether maintains the insert in tension. A method of manufacturing a waterbed mattress comprising the steps of forming a chamber of a flexible film material for holding water, positioning an insert (19) in the chamber for controlling wave action in the water, attaching a cornerpiece (21) to the film material to form a corner of the mattress, and tethering the insert to the cornerpiece to retain the insert in a predetermined position in the chamber. A method as claimed in Claim 6 wherein the insert (19) is tethered to the anchor point by passing a flexible tether (27) through an eyelet (26) attached to the cornerpiece (21). A method as claimed in Claim 7 wherein the cornerpiece (21) and the eyelet (26) are formed as a unitary structure by injection molding. A waterbed mattress comprising a plurality of bladders (46) fabricated at least in part of a flexible material defining a chamber for holding water, an insert (57) disposed in the chamber for reducing wave action in the water, means (49) affixed to the bladder forming an anchor point within the chamber, and a tether (58) extending between the insert and the anchor point to retain the insert in a predetermined position in the chamber. A waterbed mattress as claimed in Claim 9 wherein the means forming the anchor point comprises an eyelet (49) having a opening (51) through which the tether can pass. A waterbed mattress as claimed in Claim 9 or Claim 10 wherein the bladder has a tubular shape, and the anchor point (49) is disposed at one end of the tubular bladder. A waterbed mattress as claimed in any one of Claims 9 to 11 wherein the tether (58) comprises a strap which is normally in a relaxed condition when the insert is in the predetermined position.

Inventors: JOHENNING JOHN B, JOHENNING, JOHN B.
Applicants: STRATA FLOTATION INC, STRATA FLOTATION, INC.
Application year: 1991
Main classification: A47C27
IPC codes: A47C27, A47C17