Patent Publication Number: US-2017367492-A1

Title: Bassinet support

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. Non-Provisional patent application Ser. No. 14/021,934 filed Sep. 9, 2013, which claims the benefit of U.S. Provisional Patent Application Ser. No. 61/698,951 filed Sep. 10, 2012, U.S. Provisional Patent Application Ser. No. 61/817,472 filed Apr. 30, 2013, U.S. Provisional Patent Application Ser. No. 61/840,861 filed Jun. 28, 2013, and U.S. Provisional Patent Application Ser. No. 61/846,241 filed Jul. 15, 2013, the entireties of which are hereby incorporated by reference herein. 
    
    
     TECHNICAL FIELD 
     The present invention relates generally to the field of infant and childrens&#39; products, and more particularly to a child containment device having an improved mattress and mattress support assembly. 
     BACKGROUND 
     Child containment devices such as play yards, play pens, bassinets, cribs, sleepers, cradles, and the like are commonly used to provide a safe and comfortable area for infants and small children to play and rest. Such devices generally include a horizontal floor and vertical walls, and may include a foldable frame structure and fabric panels extending between the frame elements for portability and ease of use. 
     Continuing improvements are sought in the field of children&#39;s products, for example for improved comfort, convenience, safety, and/or performance. Accordingly, it is to the provision of improved child containment systems, and to improved mattress support assemblies for such systems, meeting these and other needs that the present invention is primarily directed. 
     SUMMARY 
     In example embodiments, the present invention provides an improved child containment device, such as a play yard, play pen, bassinet, crib, sleeper, cradle, and the like, and/or an improved mattress support assembly for a child containment device. A raised bassinet mattress may be provided in a child containment device for supporting the infant or child above the floor, for example for napping or diaper changing, and to position the child for easier access by a care-giver. Various support assemblies within the scope of the present invention may be incorporated to maintain structural support and flatness of a mattress, and to provide for improved comfort, convenience, safety, and/or performance to a child containment system with an elevated mattress support assembly. 
     In one aspect, the present invention relates to a support structure for a mattress within a child containment device, the child containment device comprising at least one wall. The support structure preferably includes a support panel having a periphery configured to align with at least a portion of the at least one wall of the child containment device. The support structure preferably also includes at least one retractable support member for engagement with the support panel to maintain the support panel in a generally flat configuration. 
     In another aspect, the invention relates to a mattress for a child containment device. The mattress preferably includes a plurality of mattress panels and structural couplings between two or more of the plurality of mattress panels, the structural couplings allowing repositioning of the plurality of mattress panels between an expanded state and a compact state, and wherein in the expanded state, the structural couplings maintain the mattress in a generally flat configuration. 
     In still another aspect, the invention relates to a mattress for a child containment device, the mattress comprising at least two sides defining a corner therebetween, and further comprising a chamfered corner assembly at the corner for resisting curling. 
     In still another aspect, the invention relates to a child containment device. The child containment device preferably includes a mattress comprising a plurality of mattress panels and structural couplings between two or more of the plurality of mattress panels, the structural couplings allowing repositioning of the plurality of mattress panels between an expanded state and a compact state, and wherein in the expanded state, the structural couplings maintain the mattress in a generally flat configuration. The child containment device preferably also includes a support structure for supporting the mattress in its expanded state, the support structure comprising a support panel having a periphery configured to align with at least a portion of a wall of the child containment device, and at least one retractable support member for engagement with the support panel to maintain the support panel in a generally flat configuration. 
     These and other aspects, features and advantages of the invention will be understood with reference to the drawing figures and detailed description herein, and will be realized by means of the various elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following brief description of the drawings and detailed description of the invention are exemplary and explanatory of preferred embodiments of the invention, and are not restrictive of the invention, as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a child containment apparatus having a bassinet mattress support assembly according to an example embodiment of the invention. 
         FIG. 2  is a perspective view of a bassinet mattress and support assembly for a child containment apparatus according to another example embodiment of the invention. 
         FIG. 3  is a perspective view of a bassinet mattress and support assembly for a child containment apparatus according to another example embodiment of the invention. 
         FIGS. 4 and 5  are perspective views of a bassinet mattress and support assembly for a child containment apparatus according to another example embodiment of the invention. 
         FIG. 6  is a perspective view of a bassinet mattress and support assembly for a child containment apparatus according to another example embodiment of the invention. 
         FIG. 7  is a perspective view of a bassinet mattress and support assembly for a child containment apparatus according to another example embodiment of the invention. 
         FIG. 8  is a perspective view of a bassinet mattress and support assembly for a child containment apparatus according to another example embodiment of the invention. 
         FIGS. 9 and 10  show perspective views of child containment devices having a bassinet mattress support assembly according to alternative example embodiments of the invention. 
         FIG. 11  is a perspective view of a child containment apparatus having a bassinet mattress support assembly according to another example embodiment of the invention. 
         FIG. 12  is a perspective view of a child containment apparatus having a bassinet mattress support assembly according to another example embodiment of the invention. 
         FIG. 13  is a perspective view of a bassinet mattress and support assembly for a child containment apparatus according to another example embodiment of the invention. 
         FIGS. 14A and 14B  are a perspective view and a partial detail view of a bassinet mattress and support assembly for a child containment apparatus according to another example embodiment of the invention. 
         FIGS. 15A, 15B and 15C  show a perspective view and side views showing a sequence of operation of a child containment apparatus having a bassinet mattress support assembly according to another example embodiment of the invention. 
         FIGS. 16A, 16B and 16C  show a perspective view and side views showing a sequence of operation of a child containment apparatus having a bassinet mattress support assembly according to another example embodiment of the invention. 
         FIGS. 17A, 17B and 17C  show a perspective view and side views showing a sequence of operation of a child containment apparatus having a bassinet mattress support assembly according to another example embodiment of the invention. 
         FIGS. 18A, 18B, 18C and 18D  show perspective and side views showing a sequence of operation of a child containment apparatus having a bassinet mattress support assembly according to another example embodiment of the invention. 
         FIGS. 19A, 19B, 19C and 19D  show perspective, side and partial detail views of a child containment apparatus having a bassinet mattress support assembly according to another example embodiment of the invention. 
         FIGS. 20A, 20B and 20C  show a perspective view and side views showing a sequence of operation of a child containment apparatus having a bassinet mattress support assembly according to another example embodiment of the invention. 
         FIGS. 21A, 21B and 21C  show a perspective view and side views showing a sequence of operation of a child containment apparatus having a bassinet mattress support assembly according to another example embodiment of the invention. 
         FIGS. 22 and 23  show perspective detail views of a child containment apparatus having a bassinet mattress support assembly according to another example embodiment of the invention. 
         FIGS. 24, 25 and 26  show perspective and partial detail views of a child containment apparatus having a bassinet mattress support assembly according to another example embodiment of the invention. 
         FIGS. 27, 28 and 29  show partial detail views of a previously known bassinet mattress ( FIG. 27 ) and an improved bassinet mattress ( FIGS. 28 and 29 ) according to another example aspect of the invention. 
     
    
    
     DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS 
     The present invention may be understood more readily by reference to the following detailed description of the invention taken in connection with the accompanying drawing figures, which form a part of this disclosure. It is to be understood that this invention is not limited to the specific devices, methods, conditions or parameters described and/or shown herein, and that the terminology used herein is for the purpose of describing particular embodiments by way of example only and is not intended to be limiting of the claimed invention. Any and all patents and other publications identified in this specification are incorporated by reference as though fully set forth herein. 
     Also, as used in the specification including the appended claims, the singular forms “a,” “an,” and “the” include the plural, and reference to a particular numerical value includes at least that particular value, unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” or “approximately” one particular value and/or to “about” or “approximately” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment. 
     With reference now to the drawing figures, wherein like reference numbers represent corresponding parts throughout the several views,  FIG. 1  illustrates an example bassinet mattress support assembly  100 , according to one embodiment of the present invention. As shown, the bassinet mattress support assembly  100  comprises a sidewall enclosure  102  coupled to a floor panel  104  and can be configured to be suspended within a play yard  106  or other child containment device. The floor panel  104  is generally rectangular, having a length that is longer than its width. At least one reinforcing rod  108  is coupled to the floor panel  104  and is selectively positionable in a functional configuration and a storage configuration. In the functional configuration, the reinforcing rods  108  lie on top of the floor panel  104  and are oriented parallel to the length of the floor panel. The rods  108  can provide support to a mattress (not shown) positioned on the floor panel  104 . In the storage configuration, the reinforcing rods  108  are repositioned in a substantially vertical orientation perpendicular to the floor panel  104 . The bassinet mattress support assembly  100  can include pockets  110  that retain the reinforcing rods  108  in the storage configuration, or other retaining means such as hook-and-loop fasteners, elastic loops, etc. 
       FIG. 2  illustrates an example bassinet mattress  200  for a child containment device, according to another embodiment of the present invention. The mattress  200  comprises a plurality of panels or boards  202  removably affixed to one another. A first board  202 A includes a hollow channel  204  and a second board  202 B includes an extrusion  206  that is configured to be removably received within the channel. For example, in the drawing figure, the channel  204  is a T-shaped channel and the corresponding extrusion  206  is a T-shaped extrusion. Locking interengagement of adjacent panels  202  by the cooperating engagement profiles, and the stiffening effect of the engagement profiles provides a substantially flat mattress assembly that resists sagging under the weight of a child placed on the mattress. The mattress  200  can be disposed within a liner  208  or cushioned pad or the boards  202  can include a cushioned layer to provide a comfortable support surface for a child. Cushioning inserts may be provided on the mattress panels or the liner between the engagement profiles to provide a smooth and continuous resting surface. In this manner, the panels  202  can be assembled for use as a mattress, and taken apart for more compact storage and transport. 
       FIG. 3  illustrates a mattress  300  according to another example embodiment of the present invention. One or more fasteners  302  are positioned around the perimeter of the mattress  300 . The fastener  302  is configured to removably mate with a corresponding mating fastener  304  located on a child support device, such as, for example, a play yard  306  or bassinet. For example, the fasteners  302  and  304  can be interengagable rows of zipper teeth that are fastened by zipping them together about the perimeter of the mattress. Alternative fasteners such as snaps, clips, buttons, hook-and-loop materials, and/or the like may be utilized instead of or in addition to the zipper. 
       FIGS. 4 and 5  illustrate another example embodiment of a mattress  400 , according to the present invention. The mattress  400  comprises a plurality of substantially rigid mattress panels or boards  402  hingedly coupled to one another and is convertible between an expanded configuration for use and a collapsed configuration for transport and storage. For example, the rigid boards  402  can be encased in a fabric sleeve  404  that includes seams  406  stitched between adjacent boards, which allow adjacent boards to pivot relative to one another. At least one reinforcing rod  408  is coupled to the at least one board  402  to support the boards in the expanded mattress configuration. In the depicted embodiment a pair of reinforcing rods are provided, one along each side of the mattress. Preferably, the reinforcing rods  408  are selectively positionable in a functional configuration, in which the reinforcing rods lie across a plurality of consecutive boards  402  to prohibit folding along the seams  406 , and a storage configuration, wherein the mattress  400  can fold along the seams. Optionally, the reinforcing rods  408  can be telescoping or multiple rod segments can be configured to couple end to end, to allow for more compact storage when not in use. 
       FIG. 6  illustrates another example embodiment of a mattress  600 , according to the present invention. The mattress  600  comprises a plurality of substantially rigid mattress panels or boards  602  hingedly coupled to one another by one or more hinge mechanisms  604 , such that the mattress is convertible between an expanded configuration and a collapsed configuration. The boards  602  can include integral stop surfaces  606  configured to interengage at the interface between adjacent boards to prevent the boards from rotating more than 180° with respect to one another in the expanded configuration of the mattress and maintain flatness (i.e., a generally planar configuration) of the mattress under the weight of a child placed thereon. The mattress  600  can be disposed within a liner  608  or the boards  602  can include a cushioned layer to provide a comfortable support surface for a child. 
       FIG. 7  illustrates another example embodiment of the bassinet  700 , according to the present invention. As shown, the bassinet  700  comprises a sidewall enclosure  702  coupled to an elevated floor or support panel  704  and is configured to be suspended within a play yard  706  or other child containment device. At least one telescoping reinforcing rod  708  is coupled to the bassinet floor  704  and is selectively positionable between an extended configuration and a collapsed configuration. A mattress can be installed over the support panel or can be integrally formed therewith. 
       FIG. 8  illustrates yet another example embodiment of a mattress  800 , according to the present invention. The mattress comprises a plurality of substantially rigid mattress panels or boards  802  removably affixed to one another. The panels of the mattress  800  can include one or more socket panels  804  configured to receive a portion of a first board  802 A and a portion of a second board  802 B in opposite sides thereof, in order to secure the first and second boards together. Alternatively, each board can include a male insertion profile on one side and a female receiver profile on the other side, so that boards can be assembled by interengagement of the respective profiles in a tongue-and-groove fashion into a substantially planar mattress assembly. The mattress  800  can be disposed within a liner  806  or the boards  802  can include a cushioned layer to provide a comfortable support surface for a child. 
       FIGS. 9 and 10  illustrate additional example embodiments of a bassinet  900 , according to the present invention. The bassinet  900  comprises a sidewall enclosure  902  coupled to a floor panel  904  and is configured to be suspended within a play yard  906  or other child containment device. The bassinet  900  can include one or more reinforcing rods  908  configured to pivot between a functional configuration (solid lines), wherein the reinforcing rods lie diagonally across the floor panel  904  and can provide support to a mattress (not shown) positioned on the floor panel, and a storage configuration (broken lines), wherein the reinforcing rods are pivoted to a substantially vertical orientation perpendicular to the floor panel. In alternate embodiments, the reinforcing rods  908  can be configured to slide downward when pivoted to the storage configuration, so that the reinforcing rods do not extend above the upper perimeter of the play yard  906 . 
       FIG. 11  illustrates another example embodiment of a bassinet  1100 , according to the present invention. The bassinet  1100  comprises a sidewall enclosure  1102  coupled to a floor panel  1104  and is configured to be suspended within a play yard  1106  or other child containment device. The bassinet  1100  can include one or more reinforcing rods  1108  configured to pivot between a functional configuration (solid lines), wherein the reinforcing rods lie diagonally across the floor panel  1104  and can provide support to a mattress (not shown) positioned on the floor panel, and a storage configuration (broken lines), wherein the reinforcing rods are pivoted to a substantially vertical orientation perpendicular to the floor panel. In this example embodiment, the bassinet  1100  also includes a central connection hub  1110  configured to releasably couple inner ends of the reinforcing rods  1108  together. Additionally, the reinforcing rods  1108  are optionally configured to telescope between an extended configuration and a collapsed configuration. 
       FIG. 12  illustrates another example embodiment of the bassinet  1200  of the present invention. The bassinet  1200  comprises a sidewall enclosure  1202  coupled to a floor panel  1204  and is configured to be suspended within a play yard  1206  or other child containment device. One or more substantially rigid plates  1208  are secured to the floor panel  1204  and are configured to provide support to a mattress  1210  when the mattress is positioned atop the floor panel. The plates  1208  can be positioned adjacent to hinge points  1212  on the mattress  1210  to prevent the mattress from bending at the hinge points. 
       FIG. 13  illustrates another example embodiment of a mattress  1300 , according to the present invention. The mattress  1300  comprises a plurality of substantially rigid boards  1302  hingedly coupled to each other by one or more hinge mechanisms  1304 , such that the mattress is convertible between an expanded configuration and a collapsed configuration. The mattress  1300  is preferably configured with abutment faces at confronting ends of the boards such that adjacent boards  1302  cannot rotate more than 180° with respect to one another. In this manner, the mattress is self-supporting and maintains a substantially flat profile in its expanded state (hinged open) under load of a child supported thereon, and can be folded into a compact configuration for storage and transport. The mattress  1300  can be disposed within a liner  1306  or the boards  1302  can include a cushioned layer to provide a comfortable support surface for a child. 
       FIG. 14A  illustrates another example embodiment of a mattress  1400 , according to the present invention. The mattress  1400  comprises a plurality of substantially rigid panels or boards  1402  hingedly coupled to each other by one or more hinge mechanisms  1404  (shown in greater detail in  FIG. 14B ), such that the mattress is convertible between an expanded configuration and a collapsed configuration. The mattress  1400  is preferably configured such that adjacent boards  1402  cannot rotate more than 180° with respect to one another. The mattress  1400  can be disposed within a liner  1406  or the boards  1402  can include a cushioned layer to provide a comfortable support surface for a child. 
       FIGS. 15A-15C  illustrate another example embodiment of a mattress  1500 , according to the present invention. The mattress  1500  comprises a plurality of substantially rigid panels or boards  1502  and is convertible between an expanded configuration and a collapsed configuration. Each board  1502  includes a support rod  1504  that is pivotally connected to a central hub  1506 . In the expanded configuration, the rods  1504  fan or pivot outwardly, fanning out the boards  1502  to form a substantially flat, horizontal mattress  1500  that can support a child. In the collapsed configuration, the rods  1504  pivot inward, folding the boards  1502  up into a vertical or otherwise more compact configuration for storage or travel. 
       FIGS. 16A-16C  illustrate another example embodiment of a mattress  1600 , according to the present invention. The mattress  1600  comprises a plurality of substantially rigid, telescoping panels or boards  1602  and is convertible between an extended configuration, wherein the telescoping boards are slid out from one another, lengthening the mattress  1600 , and a collapsed configuration, wherein the telescoping boards are slid or nested at least partially inside one another, shortening the mattress. In the extended position, the mattress  1600  can be positioned within a play yard, bassinet, or other child containment device and is configured to support a child. 
       FIGS. 17A-17C  illustrate another example embodiment of a mattress  1700 , according to the present invention. The mattress  1700  comprises a plurality of substantially rigid panels or boards  1702  adapted to support a child. The mattress  1700  is configured to be positioned on the floor or other support surface of a suspended child support device within a child containment system such as a bassinet or play yard. One or more drop bars or support columns  1704  is/are configured to extend between the mattress  1700  and a support surface (e.g. the ground or the floor of a play yard  1706 ) to provide support to the suspended mattress. In the drawing figure, the lower end of the support column  1704  is configured to engage a portion of the play yard  1706 , such as for example a bottom frame hub or other structural component of the play yard. In some example embodiments, the support column  1704  can be pivoted (or otherwise moved) to a collapsed configuration for easy storage or travel. 
       FIGS. 18A-18D  illustrate another example embodiment of a mattress  1800 , according to the present invention. The mattress  1800  comprises a plurality of substantially rigid panels or boards  1802  hingedly coupled to each other by one or more hinge mechanisms  1804 , such that the mattress is convertible between an expanded configuration and a collapsed configuration. The mattress  1800  is preferably configured such that adjacent boards  1802  cannot rotate more than 180° with respect to one another. In the extended position, the mattress  1800  can be positioned within a play yard, bassinet, or other child containment device and is configured to support a child. 
       FIGS. 19A-19D  show a play yard  1900  according to an example embodiment of the present invention. The play yard  1900  includes a lower frame  1902 , upper frame  1904 , and one or more support legs  1906  extending vertically between the lower and upper frames. One or more reinforcing rods  1908  are coupled to the support legs  1906  and extend generally horizontally and diagonally across the interior of the play yard  1900 . The reinforcing rods  1908  are configured to support a bassinet floor and/or mattress (not shown) positioned within the play yard  1900 . In some embodiments, the reinforcing rods  1908  are foldable to a collapsed configuration. One or more connection pins are optionally provided to connect the rods and/or forming pivot joints for extension and collapsibility of the support structure. 
       FIGS. 20A-20C  illustrate an example embodiment of yet another mattress  2000 , according to the present invention. The mattress  2000  comprises a plurality of substantially rigid panels or boards  2002  hingedly coupled to one another. One or more loops  2004  are attached around or along one or more sides of the perimeter edge of the mattress  2000  and are configured to removably receive one or more corresponding bars or hooks  2006  attached to a child support device, such as a bassinet or a play yard  2008 , in order to secure the mattress to the child support device. In alternative embodiments, the loops  2004  are attached to the child support device and the hooks  2006  are attached to the mattress  2000 . 
       FIGS. 21A-21C  illustrate an example embodiment of another mattress  2100 , according to the present invention. The mattress  2100  comprises a plurality of substantially rigid panels or boards  2102  hingedly coupled to one another. One or more hooks  2104  are attached around or along one or more sides of the perimeter edge of the mattress  2100  and are configured to removably engage one or more support bars or rails  2106  attached to a child support device, such as a bassinet or a play yard  2108 , in order to secure the mattress to the child support device. Alternatively, the hooks may be secured along the side(s) of the child support device and the rails secured along the edge(s) of the mattress. In still further alternative embodiments, the mattress includes loops configured to slide onto the rails. 
       FIGS. 22 and 23  illustrate another bassinet  2200 , according to an example embodiment of the present invention. The bassinet  2200  comprises a sidewall enclosure  2202  coupled to a floor panel  2204  and is configured to be suspended within a play yard  2206  to support a mattress or forming an integral mattress and support structure. At least one fastener  2208  is coupled to the underside of the floor panel  2204  and is configured to removably engage at least one corresponding mating fastener  2210  located on the play yard  2206 . For example, the fastener  2208  can be a female buckle component and the mating fastener  2210  can be a male buckle component adapted to releasably engage the female buckle component. When the fastener  2208  and mating fastener  2210  are engaged, the floor panel  2204  is pulled substantially taut, minimizing or eliminating sagging of the floor panel. Optionally, straps to which the fasteners are affixed can provide length adjustment for tightening or loosening the floor panel. In example embodiments, a plurality of releasable interengaging cooperative fastener pairs are spaced about the periphery or about one or more side(s) of the play yard and the periphery or side(s) of the floor panel at corresponding locations. For example, two or more (four are depicted) fasteners may be provided along each side edge of the support panel. In alternate embodiments, the fasteners can comprise resilient snap couplings, buckles, clips, and the like. 
       FIGS. 24, 25, and 26  illustrate another example embodiment of a bassinet  2400 , according to the present invention. The bassinet  2400  comprises a sidewall enclosure  2402  coupled to a floor panel  2404  and is configured to be suspended within a play yard  2406 . At least one reinforcing strap  2408  is coupled to the sidewall enclosure. Preferably, the reinforcing strap  2408  extends along the height of the sidewall enclosure  2402  substantially perpendicular to the floor panel  2404 . In some example embodiments, the reinforcing strap  2408  terminates at or before the floor panel  2404 . In other example embodiments, the reinforcing strap  2408  continues at least partially across the floor panel  2404 , as shown in  FIG. 26 , optionally extending beneath and/or across the floor panel. A mattress  2410  adapted to support a child can be removably placed atop the floor panel  2404 , or alternatively the floor panel can comprise an attached or integral mattress assembly. Example embodiments of mattress  2410  can be foldable, for example according to one or more example embodiments described herein, and the reinforcing straps  2408  can be positioned to align with and provide support to the fold lines  2412  of the mattress. 
     In further alternative embodiments of a bassinet according to the present invention, the bassinet comprises a sidewall enclosure coupled to a floor panel. One or more fasteners are secured to the floor panel and are configured to mate with one or more corresponding mating fasteners secured to a mattress when the mattress is positioned atop the floor panel. The fasteners and mating fasteners can be, for example, hook and loop fasteners, snaps, magnets, or another convention fastener. Alternatively, the floor panel and/or mattress can include rubber strips or other retention elements configured to prevent the mattress from sliding on the floor panel. 
       FIGS. 28 and 29  show a chamfered corner  2800  of a mattress panel  2802  according to another example aspect of the invention. In example embodiments, the corner  2800  comprises a living hinge, for example formed by stitching a seam between the mattress end and side, for example forming a foldable triangular tab at the corner of the mattress. When the mattress is installed into a play yard  2900 , the chamfered corner  2800  folds at least partially upright to provide increased stiffening to resist rolling or curling of the end of the mattress, thereby maintaining a flatter mattress configuration than with a standard mattress corner as shown in  FIG. 27 . Cushioning or stiffening material within the mattress may be reduced or omitted at the fold line of the chamfered corner  2800 , allowing the fabric or other outer shell material of the mattress  2802  to function as an integral hinge. 
     While the invention has been described with reference to preferred and example embodiments, it will be understood by those skilled in the art that a variety of modifications, additions and deletions are within the scope of the invention, as defined by the following claims.