Grouped screw bunch and related method and machine for production of the same

Abstract

A screw bunch includes a plurality of screws grouped together in a bunch with the enlarged head end of each screw toward a first end of the bunch and the pointed tip end of each screw toward a second end of the bunch. The screws are held together in the bunch by a band structure that extends around the bunch and that engages with the shanks of a multiplicity of the screws that are located along a perimeter of the bunch. The enlarged head ends of the screws are axially staggered. The band structure may be formed by a shrink wrap plastic band that can be separated from the bunch manually to enable individual retrieval of screws from the bunch for use. A method and machinery for production of the screw bunch is also provided.

What is claimed is: 
     
         1 - 16 . (canceled) 
     
     
         17 . A method of producing a screw bunch, comprising:
 positioning a plurality of screws in a set with head ends of the screws commonly oriented toward one axial end of the set and with the head ends having axially staggered positions relative to each other;   positioning a band member about the set of screws;   tightening the band member about the set of screws causing the set to collapse inwardly toward a central axis of the set.   
     
     
         18 . The method of  claim 17 , including:
 separating a plurality of screws into a plurality of screw sets, each screw set including a common number of screws;   dropping one screw set into a tubular member;   applying a shrink sleeve member around the tubular member;   moving the tubular member to a raised position to expose the one screw set, such that the tubular member is no longer positioned between the shrink sleeve member and the one screw set, wherein, in the first raised position, the tubular member surrounds an upper end of the one screw set;   applying heat to the shrink sleeve member while the tubular member is in the raised position, causing the shrink sleeve member to shrink into holding contact with the one screw set to form a wrapped screw bunch;   cooling the shrink sleeve member;   moving the tubular member to a further raised position that is higher than the first raised position, such that the wrapped screw bunch is no longer surrounded by the tubular member and can be removed.   
     
     
         19 . The method of  claim 18  wherein the tubular member is moved to an intermediate raised position after applying the heat and before the cooling, where the intermediate raised position is higher than the raised position and lower than the further raised position. 
     
     
         20 . The method of  claim 17  including:
 positioning the plurality of screws of the set within a tubular member; 
 applying the band member, in the form of a shrink sleeve member, around the tubular member; 
 moving the tubular member to a first set position to expose the screws of the set, such that the tubular member is no longer positioned between the shrink sleeve member and the screws; 
 applying heat to the shrink sleeve member while the tubular member is not positioned between the shrink sleeve member and the screws, causing the shrink sleeve member to shrink into holding contact with the screws to collapse the screws and form a wrapped screw bunch; 
 cooling the shrink sleeve member. 
 
     
     
         21 . A method of producing a screw bunch, comprising:
 separating a plurality of screws into a plurality of screw sets, each screw set including a common number of screws;   selectively feeding one screw set of the plurality of screw sets into a standby position of a drop funnel;   positioning a loading station that includes a tubular member below an outlet opening of the drop funnel;   dropping the one screw set from the drop funnel and into the tubular member;   applying a shrink sleeve member around the tubular member;   moving the tubular member to a first raised position to expose the one screw set, such that the tubular member is no longer positioned between the shrink sleeve member and the one screw set, wherein, in the first raised position, the tubular member surrounds an upper end of the one screw set;   applying heat to the shrink sleeve member while the tubular member is in the first raised position, causing the shrink sleeve member to shrink into holding contact with the one screw set to form a wrapped screw bunch;   cooling the shrink sleeve member;   moving the tubular member to a second raised position that is higher than the first raised position, such that the wrapped screw bunch is no longer surrounded by the tubular member and can be removed from the loading station.   
     
     
         22 . The method of  claim 21 , wherein the applying heat step is a primary heating step and the method further comprises applying further heat to the shrink sleeve member in a secondary heating step to cause the shrink sleeve member to further shrink. 
     
     
         23 . The method of  claim 22  wherein the secondary heating step occurs after the cooling step. 
     
     
         24 . The method of  claim 23  wherein a secondary cooling step occurs after the secondary heating step. 
     
     
         25 . The method of  claim 21  wherein:
 in the separating step each screw set is moved into a respective channel of a carousel; 
 the one screw set is selectively fed to the standby position by rotating the carousel such that an outfeed end of a channel holding the one screw set aligns with a carousel gate that leads to a feed track that runs downward to the drop funnel such that the screws of the one screw set slide down along the feed track and into the standby position; 
 the loading station is positioned below the outlet opening of the drop funnel by rotating a station turntable; 
 the one screw set is dropped from the drop funnel by linear movement of a gate member from a hold position to a drop position, wherein, in the hold position, the gate member supports the screws of the one screw set by engagement with the enlarged head ends of the screws and wherein, in the drop position, the gate member moves away from the enlarged head ends of the screws; 
 the tubular member is moved to the first raised position by engaging the tubular member with a tube lifter, wherein the tube lifter has a lower end, an upper end for engaging the tubular member and a radially inner end, wherein the lower end includes a lower roller that rides upward along a ramp surface as the station turntable rotates to a position for applying heat, wherein the radially inner end includes an inner roller that rides within a cam slot as the station turntable rotates and the cam slot is configured such that tube lifter is disengaged from the tubular member when the shrink sleeve member is applied around the tubular member and such that the tube lifter moves into engagement with the tubular member after the shrink sleeve member is applied around the tubular member and before the lower roller rides upward along the ramp surface; 
 the heat is applied to the shrink sleeve member by rotating the loading station through a curved heat shrink tunnel; 
 the cooling is performed by blowing air onto the shrink sleeve member through one or more openings in the station turntable that are located proximate to the loading station; and 
 the tubular member is moved to the second raised position as the station turntable rotates causing the lower roller to ride upward along a second ramp surface. 
 
     
     
         26 . A machine for producing wrapped screw bunches, comprising:
 a turntable including a plurality of screw load stations, the turntable rotatable about a first rotation axis, each screw load station including an associated tubular member and an associated tube lifter;   a carousel including a plurality of downwardly sloped screw channels for supporting groups of screws, the carousel rotatable about a second rotation axis, the carousel surrounded by a stationary wall having an outlet gate that is selectively alignable with an outfeed end of each screw channel based upon rotational position of the carousel;   a curved feed track running downwardly from the outlet gate such that screws can slide downward along the feed track, the feed track having an outlet end;   a drop funnel having a support track with an inlet end that is aligned with the outlet end of the feed track, the support track formed in part by a wall of the drop funnel and in part by a movable gate of the drop funnel, the drop funnel including a bottom opening;   wherein each screw load station is rotatable along a path that includes a position below the bottom opening so that a group of screws can be dropped into the tubular member of the load station to form a loaded tube.   
     
     
         27 . The machine of  claim 26 , further comprising:
 a shrink sleeve applicator located along the path, in a position that follows the drop funnel, for applying a shrink sleeve member around the loaded tube,   wherein the tube lifter is moved to a position away from the tubular member during application of the shrink sleeve member.   
     
     
         28 . The machine of  claim 27 , further comprising:
 a shrink sleeve heater located along the path, in a position that follows the shrink sleeve applicator, for applying heat to the shrink sleeve member,   wherein, during shrink sleeve heating, the tube lifter is moved to a position engaging the tubular member and lifting the tubular member to a raised position such that the screws in the loaded tube are at least partially exposed and the tubular member is no longer positioned between the shrink sleeve member and the screws.   
     
     
         29 . The machine of  claim 28 , further comprising:
 a shrink sleeve cooling station located along the path, in a position that follows the shrink sleeve heater, at which cooling air is blown onto the shrink sleeve member.   
     
     
         30 . The machine of  claim 29 , wherein the tube lifter includes a lower end, an upper end for engaging the tubular member and a radially inner end, wherein the radially inner end includes an inner roller that rides within a cam slot as the turntable rotates, wherein the cam slot is configured such that tube lifter is spaced away from the tubular member when the tubular member aligns with the shrink sleeve applicator, wherein the cam slot is configured such that the tube lifter moves back toward and into engagement with the tubular member as the tubular member moves toward the shrink sleeve heater, wherein the lower end includes a lower roller that rides upward along a ramp surface as the turntable rotates to move the tubular member through the shrink sleeve heater. 
     
     
         31 . The machine of  claim 27 , wherein each loading station includes a screw support surface that is non-planar. 
     
     
         32 . The machine of  claim 31 , wherein each screw support surface is conical.