Device and method for tying a knot

Abstract

An automatic machine that holds, inflates, then securely knots ordinary latex party balloons without using accessories includes a filling nozzle, surrounding clamps, and a balloon neck stretcher. Two closable jaws can be raised, lowered, advanced, retracted and twisted about the stretched neck so that a knot is formed in the stretched neck prior to release of the balloon. Mechatronics techniques make the required motions. An optional supply mechanism pre-mounts balloons on rows of nozzles on parallel sliding strips, so that a particular strip can be selected and moved to cause inflation and knotting.

1 . Knot-tying mechanical apparatus employing mechatronics for forming a knot near an end of a flexible elongate element ( 60   a ), characterised in that the apparatus includes releasable means ( 14  with  30 ), and means  40  to hold a length of the flexible elongate element in tension during a knotting process across a space near to a hooking mechanism having a rotatable shaft ( 52 ) and a tangential projection or hook ( 51 ,  51 ) extending from said shaft; the hooking mechanism being capable of moving within the space in order to make contact with a first portion of the elongate element then of twisting the first portion into a loop by rotating the hook, said hook including releasable gripping means capable of grasping a second portion of said elongate element and then orienting the second portion towards holding means  40 ; meanwhile releasing the releasable means, and means ( 40 ) to pull one end of the elongate element, and thereby draw the looped first portion over and past the gripping means and the held second portion of the elongate element; and thereby forming a knot ( 60   c ) in use. 
     
     
         2 . Knot-tying apparatus as claimed in  claim 1  adapted for inflating and then sealably tying a latex rubber balloon, characterised in that the apparatus includes: a hook ( 51 ,  51 ) having a shaft ( 52 ) lying generally on an axis of rotation and a tangential projection ( 51 ) from said shaft, by which in use a first portion of the elongate element (a neck of the balloon) can be caught and twisted into a loop by rotation of the hook, said projection including releasable gripping means by which a second portion of said elongate element can be grasped in use; and means ( 40 ) to apply tension to the elongate element, and thereby draw the looped first portion over, and past the gripping means and the held second portion of the elongate element and thereby form a knot ( 60   c ) in use. 
     
     
         3 . Knot-tying apparatus as claimed in  claim 2 , characterised in that the gripping means comprises a pivotally connected pair of jaws ( 51 ) tapering to a narrow distal point ( 51   b ) from a wide rounded base ( 51   a ) proximal to said shaft ( 52 ). 
     
     
         4 . Knot-tying apparatus as claimed in  claim 3 , characterised in that the jaws have dished facing edges ( 51   c ) which can be substantially adjoined to form a cup ( 71 ) between them, whereby in use an end (mouth  60   b ) of the elongate element can be seated in said cup, such that the looped first portion of the elongate element is capable of being drawn over and past said end when drawn over and past the jaws ( 51 ) and the held second portion of the elongate element to form a knot in use. 
     
     
         5 . Knot-tying apparatus as claimed in  claim 4 , characterised in that at least one said jaw ( 51 ) is provided with a detent ( 70 ) on an outward edge positioned distally relative to a widest part of said rounded base ( 51   a ) but proximally relative to said cup ( 71 ). 
     
     
         6 . Knot-tying apparatus as claimed in  claim 2 , wherein the hook is tiltable between a first orientation ( FIG. 3   e ) in which in use a first portion of the elongate element can be caught and twisted into a loop, and a second orientation ( FIG. 3   j ) in which said second portion of said elongate element can be grasped and the elongate element pulled to draw the looped first portion over and past the gripping means ( 51 ) and the held second portion of the elongate element, and thereby form a knot in use. 
     
     
         7 . Knot-tying apparatus as claimed in  claim 2 , characterised in that the apparatus further includes a clamp ( 30 ) to releasably hold an end of said elongate element ( FIG. 3   b ), and stretching means ( 40 ) movable to draw out the elongate element away from said held end of the elongate element ( FIG. 3   d ). 
     
     
         8 . Knot-tying apparatus as claimed in  claim 7 , characterised in that said stretching means ( 40 ) is capable of movement in at least two directions, a first direction away from said held end of the elongate element ( FIG. 3   d ), and a second direction transverse to said first direction to pull the elongate element ( FIG. 31 ) to draw the looped first portion over and past the gripping means ( 51 ) and the held second portion of the elongate element, and thereby form a knot in use. 
     
     
         9 . Knot-tying apparatus as claimed in  claim 8 , characterised in that said stretching means ( 40 ) includes a pair of prongs ( 41 ,  42 ) dimensioned and arranged to allow the elongate element ( 60   a )  575  to lie between them, whereby in use said prongs can engage with a wider body of said elongate element when moved in said first direction, to draw out the elongate element away from said held end of the elongate element ( FIG. 3   d ). 
     
     
         10 . Knot-tying apparatus as claimed in  claim 9 , characterised in that said stretching means ( 40 ) further includes a latch ( 43 ) at a distal end of one said prong ( 41 ), movable to engage or disengage with a distal end of the other said prong ( 42 ), whereby when engaged in use said latch can pull said elongate element when moved in said second direction ( FIG. 31 ) to draw the looped first portion over and past the gripping means ( 51 ) and the held second portion of the elongate element, and thereby form a knot in use. 
     
     
         11 . Knot-tying apparatus as claimed in  claim 7 , characterised in that the elongate element ( 60   a ) comprises the neck of the balloon ( 60 ), and wherein said held end of the elongate element comprises a mouth ( 60   b ) of said balloon, the apparatus further including a gas vent ( 14 ) through which a charge of gas can be delivered from a controlled supply of gas, said clamp being arranged to releasably hold said mouth on said vent in use. 
     
     
         12 . Knot-tying apparatus as claimed in  claim 11 , characterised in that the apparatus includes a sequencing controller by which (A) the movements of said apparatus are controlled to occur in a predetermined sequence, and (B) the charge of gas provided through said vent can be controlled to partially or fully inflate a balloon in use. 
     
     
         13 . Knot-tying apparatus as claimed in  claim 12 , characterised in that a state diagram embodies the predetermined sequence used by the sequencing controller. 
     
     
         14 . Knot-tying apparatus as claimed in  claim 12 , characterised in that said gas vent is provided with a series of nozzles ( 14 ) movable between a loading position ( 14   a ) at which in use a deflated balloon can be mounted on a salt) nozzle and a discharge position ( 14   b ) at which in use a charge of gas can be provided through a said nozzle. 
     
     
         15 . Knot-tying apparatus as claimed in  claim 11 , characterised in that said plurality of nozzles ( 14 ) are provided on a rotatable spindle ( 24 ). 
     
     
         16 . Knot-tying apparatus as claimed in  claim 11 , characterised in that a plurality of said nozzles ( 130 ) are provided in a row on an elongate carrier ( 202 ) movable longitudinally from a storage position to a discharge position at which in use a charge of gas can be provided through a said nozzle. 
     
     
         17 . Knot-tying apparatus as claimed in  claim 16 , characterised in that a plurality of rows of nozzles on at least one said earlier ( 202 ) are provided in an array in a support frame ( 204 ), the support frame being movable in a flat or a curved plane relative to a direction of said longitudinal movement, whereby in use different said tows can be moved into longitudinal alignment with said discharge position. 
     
     
         18 . Knot-tying apparatus as claimed in  claim 15 , characterised in that a plurality of carriers ( 202 ) are provided, movably mounted in a plurality of removable cartridges ( 203 ) in turn mounted in said support frame ( 204 ). 
     
     
         19 . Knot-tying apparatus as claimed in  claim 17 , characterised in that a plurality of carriers ( 202 ) are mounted in a parallel series in each said removable cartridge ( 203 ). 
     
     
         20 . Knot-tying apparatus as claimed in  claim 18 , characterised in that the apparatus includes a control and monitoring system, having at least one of: (a) means ( 218 ) to detect the position of the support frame; (b) means ( 214 ) to monitor nozzles ( 130 ) in the support frame to determine which nozzles have balloons mounted on them; (c) means to determine the type of balloon held on a nozzle in the supports frame; and (d) user control means ( 211 ,  215 ) by which a type of balloon can be selected, so that the support frame and carrier can be moved under system control to present a nozzle holding a balloon of that type to the gas vent ( 205 ) in the balloon-inflating apparatus. 
     
     
         21 . Knot-tying apparatus as claimed in  claim 15 , characterised in that the apparatus further includes at least one of: (a) sensing means ( 213 ) capable of detecting the presence of a balloon ( 200 ) at said gas vent ( 205 ); sensing means ( 213 ,  214 ) capable of detecting the colour of a balloon ( 200 ); sensing means ( 212 ) capable of detecting the size of a balloon ( 200 ); sensing means ( 217 ) to monitor a supply of gas at a pressure, from a compressor or a tank or a cylinder, for inflation of the balloons. 
     
     
         22 . Knot-tying apparatus as claimed in  claim 21  characterised in that the control and monitoring system further includes at least one display means, by which a nearby ( 215 ) or a remote ( 216 ) operator can be advised of the numbers and types of balloons held in the support frame. 
     
     
         23 . Knot-tying apparatus as claimed in  claim 11 , characterised in that the apparatus is slidably mounted within a protective casing ( 10   b ), such the it can be raised out of the casing when in use and the casing forms a base on which the apparatus stands. 
     
     
         24 . A method for tying an extensible cord near one end using apparatus as claimed in  claim 1 , characterised in that the method comprises the steps of: clamping a first, end portion of the cord; then clamping a second portion of the cord extending an intermediate portion of the cord: moving a hook to catch the intermediate portion, said hook having gripping means at a distal end thereof and then rotating said hook to twist a first portion of the intermediate portion into a loop; tilting the hook to catch a second portion of the intermediate portion by closing the gripping means; moving said hook anti said stretching means apart, so as to draw said looped first portion of the intermediate portion off the hook and past the gripped second portion of the intermediate portion, to form a knot during which phase the first end is released; and releasing said gripping means to release said extensible cord. 
     
     
         25 . A method according to  claim 24  adapted for distending, then tying the neck of a balloon having a mouth, a neck and an inflatable body, characterised in that the method comprises the steps of: clamping the mouth of the balloon on to a controlled gas vent; at least partially inflating the balloon with a charge of gas; engaging the body of the balloon with stretching means, and moving said stretching means away from the clamped mouth to extend the neck of the balloon: moving a hook to catch the neck of the balloon, said hook having gripping means at a distal end thereof; rotating said hook to twist a first portion of the neck into a loop; tilting said hook to catch a second portion of the neck with said gripping means; moving said hook and said stretching means apart, so as to draw said looped first portion of the neck off the hook and past the gripped second portion of the neck, to form a knot; and releasing said gripping means to release said balloon.