Patent Publication Number: US-11653778-B2

Title: Paper drinking straw

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a paper drinking straw. 
     Description of the Prior Art 
     Recently, with hand shake beverages become popular, the use of drinking straws is more extensive. Specifically, plastic drinking straws have advantages of low cost, lightweight and good durability so that the plastic drinking straws are frequently used. However, the plastic drinking straws are not biodegradable and inconvenient to be reused, which results in environmental pollution. 
     To reduce the pollution caused by the plastic drinking straws, drinking straws made of stainless steel, glass or silicone are provided. However, stainless steel drinking straws are relative heavy, high cost and inconvenient to clean; glass drinking straws are fragile; and silicone drinking straws are also inconvenient to clean and easy to absorb fluids and bacteria. In addition, a length of each of the drinking straws mentioned above is unchangeable, which is inconvenient to storage and carry. 
     The present invention is, therefore, arisen to obviate or at least mitigate the above-mentioned disadvantages. 
     SUMMARY OF THE INVENTION 
     The main object of the present invention is to provide a paper drinking straw which is convenient to storage and carry and is environmentally friendly and contributed to plastic waste reduction. 
     To achieve the above and other objects, the present invention provides a paper drinking straw, including: a main tube and a sub-tube. The main tube includes a first segment, a second segment and a first neck segment. An outer diametrical dimension of the first segment is larger than an outer diametrical dimension of the second segment. The first neck segment is connected between the first segment and the second segment, and the first neck segment is tapered in a direction from the first segment toward the second segment. The sub-tube is movably sleeved with the main tube and includes a third segment, a fourth segment and a second neck segment. An outer diametrical dimension of the third segment is larger than an outer diametrical dimension of the fourth segment. The second neck segment is connected between the third segment and the fourth segment, and the second neck segment is tapered in a direction from the third segment toward the fourth segment. The outer diametrical dimension of the third segment is smaller than or equal to an inner diametrical dimension of the first segment, and the outer diametrical dimension of the fourth segment is smaller than or equal to an inner diametrical dimension of the second segment. The sub-tube is movable in a stretching direction to increase a length of the fourth segment protruding beyond the second segment. When the sub-tube is moved to a predetermined position, the second neck segment is restricted to the first neck segment, and the sub-tube is unmovable in the stretching direction. 
     The present invention will become more obvious from the following description when taken in connection with the accompanying drawings, which show, for purpose of illustrations only, the preferred embodiment(s) in accordance with the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a stereogram of a preferable embodiment of the present invention; 
         FIG.  2    is a breakdown drawing of a preferable embodiment of the present invention; 
         FIG.  3    is a cross-sectional view of a preferable embodiment of the present invention; 
         FIG.  4    is a partial enlargement of  FIG.  3   ; 
         FIG.  5    is a drawing showing a paper substrate according to of a preferable embodiment of the present invention; and 
         FIG.  6    is partial side view of  FIG.  5   . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Please refer to  FIGS.  1  to  6    for a preferable embodiment of the present invention. A paper drinking straw of the present invention includes a main tube  1  and a sub-tube  2 . 
     The main tube  1  includes a first segment  11 , a second segment  12  and a first neck segment  15 . An outer diametrical dimension of the first segment  11  is larger than an outer diametrical dimension of the second segment  12 . The first neck segment  15  is connected between the first segment  11  and the second segment  12 , and the first neck segment  15  is tapered in a direction from the first segment  11  toward the second segment  12 . 
     The sub-tube  2  is movably sleeved with the main tube  1  and includes a third segment  21 , a fourth segment  22  and a second neck segment  23 . An outer diametrical dimension of the third segment  21  is larger than an outer diametrical dimension of the fourth segment  22 . The second neck segment  23  is connected between the third segment  21  and the fourth segment  22 , and the second neck segment  23  is tapered in a direction from the third segment  21  toward the fourth segment  22 . The outer diametrical dimension of the third segment  21  is smaller than or equal to an inner diametrical dimension of the first segment  11 , and the outer diametrical dimension of the fourth segment  22  is smaller than or equal to an inner diametrical dimension of the second segment  12 . The sub-tube  2  is movable in a stretching direction  4  to increase a length of the fourth segment  22  protruding beyond the second segment  12 . When the sub-tube  2  is moved to a predetermined position, the second neck segment  23  is restricted to the first neck segment  15 , and the sub-tube  2  is unmovable in the stretching direction  4 . 
     Specifically, the first neck segment  15  and the second neck segment  23  are cone-shaped respectively so as to provide different strength of restriction force therebetween according to movement of the sub-tube  2  relative to the main tube  1  in the stretching direction  4 . The longer the length of the fourth segment  22  protrudes beyond the second segment  12 , the tighter the first neck segment  15  is restricted with the second neck segment  23 , which provides good positioning effect. 
     Preferably, an end of the first segment  11  remote from the second segment  12  has a constricted portion  13 , and the constricted portion  13  extends toward an interior of the first segment  11  and is blockable with the sub-tube  2  in a direction opposite to the stretching direction  4 . In manufacturing, the sub-tube  2  is inserted within the main tube  1 , and then the constricted portion  13  is formed to block the sub-tube  2  from removing from the main tube  1  in the direction opposite to the stretching direction  4 . In other words, the main tube  1  effectively restricts the sub-tube  2  by the constricted portion  13  and the first neck segment  15  to prevent the sub-tube  2  from removing therefrom. 
     The main tube  1  further includes at least one blocking unit  14  protruding from an inner wall of the first segment  11 . When the sub-tube  2  is received within the second segment  12 , the third segment  21  is located at a side of the at least one blocking unit  14  remote from the second segment  12  and is interferable with the at least one blocking unit  14  in the stretching direction  4  so as to avoid unexpected movement of the sub-tube  2  relative to the main tube  1 . When the sub-tube  2  is in the predetermined position, the at least one blocking unit  14  provides supporting force to the sub-tube  2  in the stretching direction  4 . Therefore, the sub-tube  2  is non-retractable into the main tube  1  when the sub-tube  2  is inserted through an object (such as a sealing film of a beverage). 
     In this embodiment, the main tube  1  includes two said blocking units  14 , and the two said blocking units  14  are arranged on radial opposite sides of the main tube  1  so as to stably support the sub-tube  2 . Moreover, the first segment  11  has the two said blocking units recessed integrally and radially thereon, which is easy to be processed. In the stretching direction  4 , a distance between one said blocking unit  14  and the first neck segment  15  is smaller than a distance between one said blocking unit  14  and the constricted portion  13 . 
     Specifically, each said blocking unit  14  includes a blocking portion  141  and a connecting portion  142 . Relative to an axial direction of the main tube  1 , the blocking portion  141  extends obliquely toward an interior of the first segment  11  and is axially abuttable against the sub-tube  2 , and the connecting portion  142  is connected with a side of the blocking portion  141  opposite to the first neck segment  15 . Preferably, an acute angle between the axial direction and an extending direction of the blocking portion  141  is larger than an acute angle between the axial direction and an extending direction of the connecting portion  142 , and a length of the blocking portion  141  is shorter than a length of the connecting portion  142 . Therefore, the connecting portion  142  is easy to deform to allow the sub tube  2  to move to the predetermined position, and the blocking portion  141  can provide sufficient supporting force to avoid retraction of the sub tube  2 . 
     Please refer to  FIGS.  5  and  6   , the main tube  1  includes a first paper layer  31 , a second paper layer  32  and a third paper layer  33 , and shapes of the first paper layer  31 , the second paper layer  32  and the third paper layer  33  are parallelograms respectively. The first paper layer  31 , the second paper layer  32  and the third paper layer  33  are partially overlapped with one another in sequence and dislocated from one another in a predetermined distance  6  along an arrangement direction  5  to form a paper substrate  34 . The main tube  1  is formed by helically rolling up the paper substrate  34  so that the first paper layer  31 , the second paper layer  32  and the third paper layer  33  are stacked layer by layer to provide good structural strength 
     Furthermore, in the arrangement direction  5 , a portion of the third paper layer  33  protruding beyond the second paper layer  32  has a notched portion  331  disposed thereon, and the first paper layer  31  covers the notched portion  331  after helically rolling up the paper substrate  34 , so that the main tube  1  has a smooth end surface. 
     A thickness of the first paper layer  31  is smaller than a thickness of the second paper layer  32  and a thickness of the third paper layer  33 . Preferably, the second paper layer  32  and the third paper layer  33  are entirely covered by the first paper layer  31 . The first paper layer  31  is an outmost layer of the main tube  1 , and the second paper layer  32  and the third paper layer  33  are inner layers of the main tube  1 . In this embodiment, a color of the first paper layer  31  is different from a color of the second paper layer  32  and a color of the third paper layer  33 , and the color of the second paper layer  32  and the color of the third paper layer  33  are the same. 
     In summary, the paper drinking straw of the present invention is made by helically rolling up three paper layers overlapped with one another, which is environmentally friendly and has good structural strength. In addition, the paper drinking straw is stretchable by configuration of the main tube and the sub-tube, which is convenient to storage and carry. 
     Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.