Patent Publication Number: US-2019191885-A1

Title: Folding Chair Armrest with Integrated Cup Holder

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     In general, the present invention relates to the structure of the armrests that are used on folding chairs, collapsible chairs, camp chairs, beach chairs and other portable lightweight chairs. More particularly, the present invention relates to armrests that contain cop holders within the structure of the armrests. 
     2. Prior Art Description 
     There exist many different styles and models of collapsible chairs that are intended to be carried by a user. In addition to be being foldable or collapsible, such chairs are made to be as lightweight as possible while still being functionally sound. In this manner, the chair is not burdensome to carry. 
     Such chairs are often brought to the beach, to tailgates, to concerts and to other such locations that require a chair to be carried a significant distance. 
     In order to make a chair lightweight, a folding chair is typically manufactured with minimalistic armrests. Often the armrests are little more than strips of fabric or thin moldings of lightweight plastic. The armrests are strong enough to support the weight of an arm, however, the armrests have little integrity to serve any other purpose. Auxiliary items, such as cup holders and cell phone pockets are simply attached to some reinforced part of the armrest or to the support frame under the armrest. Such prior art armrests are exemplified by U.S. Patent Application Publication No. 2003/0193222 to Welsh. 
     When a cup holder is attached to an armrest in an automobile or to an armrest in a movie theater seat, there is enough mass of material to integrate the cup holder into the central structure of the armrest. This is typically done by providing a cylindrical depression into the structure of the armrest that is large enough to receive a can, cup or bottle of an average diameter. Such prior art is exemplified by U.S. Pat. No. 5,150,946 to Marfilius and U.S. Pat. No. 7,614,703 to Bergin. However, in a portable beach chair, the material available at the armrest is so thin that it makes the formation of a cup holder impractical. Furthermore, due to the scarcity of material and support, any cup holder that can be formed is little more than a hole in the material of the armrest. The cup holder does not have any specialized features, such as a tightening mechanism, that can close around small diameter cans, cups, and bottles. 
     A need therefore exists for an armrest design for a lightweight folding chair that incorporates a cup holder, wherein the cup holder is structurally sound and has the ability to retain a wide variety of cans, cups and bottles without adding significantly to the weight or cost of the armrest. This need is met by the present invention as described and claimed below. 
     SUMMARY OF THE INVENTION 
     The present invention is an armrest assembly for use on a lightweight folding chair or collapsible chair. The armrest assembly has a molded plastic body with a top surface upon which a person&#39;s arm rests. 
     The molded plastic body has an underside that is reinforced by support ribs for strength. The molded plastic body of the armrest assembly is molded in two parts. A first body section is molded of a first material and a second body section is molded of a second material. The first material is a rigid plastic material that provides the armrest assembly with strength and structural integrity. The second material is a flexible plastic material, such as a thermoplastic rubber. The second body section of flexible plastic material is overmolded onto the first body section of the rigid plastic material. 
     A cup holder construct is formed into the armrest assembly. The cup holder construct is formed within part of the rigid plastic material of the first body section and within part of the flexible plastic material of said second body section. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a better understanding of the present invention, reference is made to the following description of an exemplary embodiment thereof, considered in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a perspective view of an exemplary embodiment of an armrest assembly with a cup holder construct; 
         FIG. 2  is a bottom view of the exemplary embodiment of the armrest assembly shown with the cup holder construct; 
         FIG. 3  is an enlarged view of the cup holder construct; 
         FIG. 4  is an exploded view of the exemplary embodiment of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     Although the present invention armrest assembly can be adapted for use in many styles and models of folding chairs, the armrest assembly is shown in only one example. The exemplary embodiment is selected in order to set forth one of the best modes contemplated for the invention. The illustrated embodiment, however, is merely exemplary and should not be considered a limitation when interpreting the scope of the appended claims. 
     Referring to  FIG. 1  in conjunction with  FIG. 2  and  FIG. 3 , an armrest assembly  10  is shown that can be used on a folding chair  11 . The armrest assembly  10  includes a two-part plastic body  12 , which includes a first body section  14  and a second body section  16 . The first body section  14  and the second body section  16  are molded from two separate plastic materials. The first body section  14  is molded from a hard plastic, such as PVC. The second body section  16  of the two-part plastic body  12  is molded from a soft, flexible elastomeric plastic, such as thermoplastic rubber (TPR). 
     When complete, the two-part plastic body  12  has a generally planar top surface  18  and a peripheral side wall  20  that extends downwardly from the edges of the top surface  18 . When positioned in an unfolded chair, the top surface  18  of the two-part plastic body  12  is generally positioned in a horizontal plane and the surfaces of the peripheral side wall  20  are generally oriented in the vertical. In use, a person&#39;s arm and/or hand rests upon the top surface  18  of the two-part plastic body  12 . The top surface  18  is generally smooth with the exception of the entrance opening to a cup holder construct  24  being accessible from the top surface  18 . 
     The first body section  14  of the two-part plastic body  12  and the second body section  16  of the two-part plastic body  12  are both exposed on the top surface  18  of the two-part plastic body  12 . The elastomeric material of the second body section  16  is over-molded onto the first body section  14 . The first body section  14  of the two-part plastic body  12  is the primary structure of the two-part plastic body  12  and provides the two-part plastic body  12  with its structural strength. The first body section  14  of the two-part plastic body  12  has a first end  26  and an opposite second end  28 . The first end  26  of the first body section  14  attaches to the backrest framing  29  of the folding chair  11 . The first body section  14  of the two-part plastic body  12  is not solid. Rather, to minimize material, weight, and expense, the first body section  14  is molded to be mostly hollow. The first body section  14  of the two-part plastic body  12  does not have a smooth bottom surface. Rather, below the top surface  18  is a complex underside  30 . The underside  30  consists of a series of molded reinforcement ribs  32  within the confines of the peripheral side wall  20 . The reinforcement ribs  32  provide structural integrity and strength to the first body section  14  of the two-part plastic body  12 . 
     Referring to  FIG. 3  and  FIG. 4 , in conjunction with  FIG. 1  and  FIG. 2 , it can be seen that the cup holder construct  24  has a lower segment  34  and an upper segment  36 . The lower segment  34  is molded as part of the first body section  14  in the hard plastic material of the first body section  14 . The upper segment  36  is molded as part of the second body section  16  in the elastomeric material of the second body section  16 . 
     The lower segment  34  of the cup holder construct  24  is molded as a receptacle  25  that is large enough to receive a cup, can or bottle that is larger than the average size. The receptacle  25  has a horizontal base  38  that is suspended between side walls  40 . The side walls  40  can be custom molded or can ce formed by the reinforcement ribs  32 . The side walls  40  are vertical or diverge slightly from vertical. The base  38  can be either solid of perforated to allow for drainage. Likewise, the side walls  40  can be solid or can contain various openings  42  to reduce mass and provide for drainage. 
     The upper segment  36  of the cup holder construct  24  has a ring structure  44  that concentrically aligns over the receptacle  25 . The ring structure  44  has an inside diameter D 1  that is large enough to accommodate oversized cups, bottles and cans. In order to prevent movement of cups, cans and bottles that are average sized or undersized, a plurality of flexible tabs  46  are molded as part of the ring structure  44 . The flexible tabs  46  are symmetrically positioned around the ring structure  44  and extend inwardly toward a common center point in a common plane. In the shown embodiment, four flexible tabs  46  are illustrated. This is exemplary, and it will be understood that any plurality of flexible tabs  46  can be used. The ring structure  44  has an inner diameter D 1 . Each of the flexible tabs  46  gas a length L 1  that is at least 20 percent of the diameter D 1  of the the ring structure  44 . In this manner, the open area  48  between the various flexible tabs  46  is significantly smaller than the diameter D 1  of the ring structure  44 . Preferably, the open area  48  between the flexible tabs  46  is smaller than the average sized can, cup or bottle. The flexible tabs  46  are molded from the same elastomeric material as is the remainder of the second body section  16 . As such, the flexible tabs  46  will bend when contacted with a cup, can or bottle. If a smaller than average cup, can, or bottle is placed in the cup holder construct  24 , the flexible tabs  46  may not be contacted or may just bend a small amount. If a larger than normal cup, can or bottle is placed into the cup holder construct  24 , then the flexible tabs  46  will bend significantly. In either scenario, the flexible tabs  46  prevent a cup, can or bottle from tilting within the confines of the cup holder construct  24 . 
     Referring to  FIG. 3  and  FIG. 4 , it can be seen that the elastomeric material of the second body section  16  is overmolded onto the first body section  14  of hard plastic. To accommodate the overmolding process, a relief  50  is formed in the first body section  14  of the two-part plastic body  12  that corresponds to the size and shape of the second body section  16 . In this manner, when the second body section  16  is molded onto the first body section  14 , the top and sides of the two-part plastic body  12  remain smooth and flush across the transitions lines between body sections  14 ,  16 . 
     The armrest assembly  10  may be exposed to large variations in temperature and humidity over its working life. Since the armrest assembly  10  is made of two different plastics, the first body section  14  and the second body section  16  may react slightly differently to the changes in temperature and humidity. To prevent any chance of plastic separation, locking elements  52  are molded into the two-part plastic body  12 . The locking elements  52  can have a variety of forms. In the shown embodiment, a plurality of fins  54  are molded into the first body section  14  within the relief  50 . The fins  54  are arranged in a tight formation so that narrow gaps  56  separate the various fins  54 . When the elastomeric material of the second body section  16  is molded over the first body section  14 , the elastomeric material of the second body section  16  fills the gaps  56  between the various fins  54 . The fins  54  appear as decorative elements on the final armrest assembly  10 . However, the primary purpose of the fins  54  is to create a mechanical interlock between the material of the first body section  14  and the material of the second body section  16 . 
     It will be understood that the embodiment of the present invention that is illustrated and described is merely exemplary and that a person skilled in the art can make many variations to that embodiment. For instance, the present invention can be adapted to most any plastic armrest used on folding or collapsible chairs. All such embodiments are intended to be included within the scope of the present invention as defined by the claims.