Device and method for opening the edge of a tubular knitted article or similar

Abstract

The device comprises: a tubular member (5A; 5B) in which the articles are inserted; a plurality of mobile gripping members (49) mobile between a first closed position and a second open position, arranged on one outlet end of said tubular member; and guiding and orienting means (71, 73) associated to said outlet end of said tubular member, for guiding and orienting the tubular article inserted in said tubular member towards said gripping members.

1 . A device for opening an end of a flexible tubular article, specifically a tubular knitted article including a tubular member ( 5 A;  58 ) in which the articles (M) are inserted; a plurality of gripping members ( 45 A;  45 B) mobile between a first closed position and a second open position, arranged on one outlet end of said tubular member; and guiding and orienting means associated to said outlet end of said tubular member, for guiding and orienting the tubular article inserted in said tubular member towards said gripping members, characterized in that: said guiding and orienting means comprise two counterpoised contoured bodies ( 71 ,  73 ) which extend from said outlet end of the tubular member towards the inside of the tubular member, said counterpoised contoured bodies reciprocally delimiting a passage for said article and presenting a slanted guiding and orienting surface (X 71 , X 73 ) facing the direction of provenience of said article, the slanted surfaces of the two contoured bodies having opposite slants; and that each of said slanted surfaces present a portion which is essentially flat and a portion which is essentially helical.  
     
     
         2 . Device according to  claim 1 , characterized in that said passage presents an elongated transversal cross-section.  
     
     
         3 . Device according to  claim 1 , characterized in that four gripping members ( 45 A;  45 B) are reciprocally arranged at 90° around an axis.  
     
     
         4 . Device according to  claim 2 , characterized in that two of said gripping members, reciprocally counterpoised, are aligned according to a direction which is essentially parallel to the larger dimension of the transversal cross-section of said passage and that the other two gripping members, reciprocally counterpoised, are aligned according to a direction which is essentially orthogonal to said greater dimension.  
     
     
         5 . Device according to  claim 1 , characterized in that said two contoured bodies present two flat lateral surfaces (Y 71 , Y 73 ) laterally delimiting said elongated transversal cross-section passage.  
     
     
         6 . Device according to  claim 5 , characterized in that said flat lateral walls of said contoured bodies are essentially parallel one with respect to the other and to the axis of the tubular member.  
     
     
         7 . Device according to  claim 1  characterized in that each of said contoured bodies presents a lateral surface (S 71 ; S 73 ) which is essentially cylindrical, whose shape corresponds with the shape of the internal surface of the tubular member.  
     
     
         8 . Device according to  claim 1 , characterized in that each of said two contoured bodies consists of three portions; two lateral portions ( 71 A,  71 B;  73 A,  73 B) being integral with a unit ( 63 ) which is movable with respect to said tubular member, and an intermediate portion ( 71 C,  73 C) being integral with said tubular member; said tubular member and said unit being reciprocally mobile, to distance the unit from the outlet end of the tubular member.  
     
     
         9 . Device according to  claim 8 , characterized in that said mobile unit presents housings ( 65 ) for inserting said gripping members ( 45 A,  45 B).  
     
     
         10 . Device according to  claim 9 , characterized in that said mobile unit presents two of said seats for the gripping members arranged between the two portions which are integral with said unit of each of said two contoured bodies, each of said two housings being additionally delimited by the respective portion, integral with the tubular member, of the respective contoured body when the mobile unit is closed on the outlet end of said tubular member.  
     
     
         11 . Device according to  claim 1 , characterized in that said gripping members ( 45 A,  45 B) are carried by an annular structure ( 31 ) surrounding the axis of the tubular member and equipped with a movement which is parallel to the axis of said tubular member.  
     
     
         12 . Device according to claim  1 , characterized in that opening members are provided to open the edge of said tubular article.  
     
     
         13 . Device according to  claim 12 , characterized in that said opening members comprise stems ( 51 ) extending in a direction which is essentially parallel to the axis of said tubular member.  
     
     
         14 . Device according to  claim 11 , characterized in that said opening members are carried by said mobile annular structure ( 31 ).  
     
     
         15 . Device according to  claim 13 , characterized in that it comprises a number of said stems ( 51 ) which is the same as the number of the gripping members ( 45 A,  45 B).  
     
     
         16 . Device according to  claim 13 , characterized in that said stems are equipped with a movement between a first reciprocally closed position and a second open position.  
     
     
         17 . Device according to  claim 16 , characterized in that movement of said stems between said first and said second position is essentially parallel with respect to the movement of said gripping members between their respective first and second position.  
     
     
         18 . Device according at least to  claim 11 , characterized in that said gripping members are fitted on sliders ( 53 ) which slide on guides ( 55 ) integral with said mobile annular structure, said sliders being operated by respective actuators.  
     
     
         19 . Device according to  claim 14 , characterized in that said stems are elastically connected to said sliders.  
     
     
         20 . Device according to  claim 19  characterized in that said gripping members are operated with movements which are displaced at least in part.  
     
     
         21 . Device according to  claim 3 , characterized in that said gripping members ( 45 A,  45 B) are operated by initially controlling a first pair consisting of two counterpoised gripping members for gripping and opening the tubular article and, after the movement of said first pair, by controlling the movement of the second pair of gripping members, which are, reciprocally counterpoised to grip and open the tubular article.  
     
     
         22 . Device according to  claim 16 , characterized in that said stems are operated in a coordinated fashion with the movement of said second pair of gripping members to be taken inside the article withheld by said gripping members and subsequently opened.  
     
     
         23 . Device according to  claim 1 , characterized in that said gripping members are suction members.  
     
     
         24 . Device according to  claim 1  characterized in that said tubular member may be connected to a suction tube ( 61 ) whose inlet is arranged on the opposite side of said gripping members with respect to the outlet end of said tubular member.  
     
     
         25 . Device according to  claim 24 , characterized in that it comprises means ( 67 ) of intercepting the tubular article between the gripping members and the inlet of the suction tube.  
     
     
         26 . Device according to  claim 8 , characterized in that said suction tube ( 61 ) is connected to said mobile unit ( 63 ).  
     
     
         27 . Device according at least to  claim 11 , characterized in that said mobile annular structure ( 31 ) carrying said gripping members ( 45 A;  45 B) comprises radial pressers ( 35 ) for engaging said article and making it slide on the outer surface of said tubular member ( 5 A,  5 B) with a movement of said mobile annular structure with respect to said tubular member.  
     
     
         28 . Device according to  claim 27 , characterized in that it comprises sensors for verifying that the article has been gripped by said gripping members.  
     
     
         29 . Device according to  claim 11 , characterized in that said tubular member is formed by two tubular elements ( 5 X,  5 Y) inserted one inside the other and reciprocally axially mobile, at least part of said guiding and orienting means being integral with the innermost tubular element.  
     
     
         30 . Device according to  claim 29 , characterized in that the outermost tubular element presents slots developing from the edge of the outlet end in parallel to the axis of the tubular member.  
     
     
         31 . Device according to  claim 1 , characterized in that a collar ( 8 ) for reducing the passage cross-section of the tubular member ( 5 A,  5 B) is arranged inside said tubular member, upstream to said guiding and orienting means with the direction of advancement of the tubular article.  
     
     
         32 . Method for opening an end of a flexible tubular article, specifically a tubular knitted article, comprising the following phases: 
 pneumatically transferring said article towards one end of a tubular member;    directing the end of said article in a predetermined position with respect to a plurality of gripping units;    holding said article with said gripping members in correspondence with the end to be opened;    opening the gripping members whereby opening said ends of the article, wherein    said end edge of the article is oriented to assume a conformation which is approximately orthogonal to a first direction of reciprocal alignment of a first pair of said counterpoised gripping members,    a second pair of gripping members are aligned and counterpoised along a second direction, essentially orthogonal to said first direction, and    said article is engaged by said first pair of gripping members and stretched along said first direction, while the gripping members of the second pair are held distanced from the article; and in which the gripping members of the second pair are subsequently approached to the article, gripping the article and stretching it in said second direction.    
     
     
         33 . Method according to  claim 32 , comprising the following phases: 
 inserting a plurality of opening means in the open end of said article;    tensioning the article in correspondence with its end by said opening means;    turning the end edge of the article inside out by means of said opening means on the outer surface of said tubular member.    
     
     
         34 . Method according to  claim 33  comprising the phase of turning the entire article inside out on the outer surface of said tubular member.  
     
     
         35 . Method according to  claim 32 , in which said gripping members pneumatically engage the article.  
     
     
         36 . Method for opening an end of a flexible tubular article, specifically a tubular knitted article, comprising the following phases: 
 pneumatically transferring said article towards one end of a tubular member;    directing the end of said article in a predetermined position with respect to a plurality of gripping units;    holding said article with said gripping members in correspondence with the end to be opened;    opening the gripping members whereby opening said ends of the article.    
     
     
         37 . Method according to  claim 36 , comprising the following phases: 
 inserting a plurality of opening means in the open end of said article;    tensioning the article in correspondence with its end by said opening means;    turning the end edge of the article inside out by means of said opening means on the outer surface of said tubular member.    
     
     
         38 . Method according to  claim 37  comprising the phase of turning the entire article inside out on the outer surface of said tubular member.  
     
     
         39 . Method according to  claim 36 , in which said end edge of the article is oriented to assume a conformation which is approximately orthogonal to a first direction of reciprocal alignment of a first pair of said counterpoised gripping members, and wherein a second pair of gripping members are aligned and counterpoised along a second direction, essentially orthogonal to said first direction.  
     
     
         40 . Method said first pair of gripping members and stretched along said first direction, while the gripping members of the second pair are held distanced from the article; and in which the gripping members of the second pair are subsequently approached to the article, gripping the article and stretching it in said second direction.  
     
     
         41 . Method according to  claim 36  in which said gripping members pneumatically engage the article.