METHOD OF SEALING A BAG AND A BAG SEALING APPARATUS
The invention provides a method of sealing a bag (8) comprising (a) gripping the neck (10) of the bag (8) (b) passing the gripped portion of the bag neck (10) around a rod (6) approximately a complete revolution (c) continuing to revolve the gripped portion of the bag and moving the gripped portion axially away from the distal end of the rod (6) until generally a further 2-300 degree revolution has been completed so that the neck (10) of the bag (8) is wrapped around the rod (6) (d) opening a recess (14) in the rod and placing the free end of the neck (10) into the recess, and (e) holding the free end in the recess (14) whilst withdrawing the rod (6) through the wrapped portion of the neck. The invention also provides apparatus for carrying out the method.
This invention relates to the sealing of bags such as bags for containing meat or agricultural produce such as root crops.
Conventionally, bags are sealed using stitching (for bags made from woven material) or welding techniques (for plastics bags). These methods are effective in sealing; however, these methods create problems when the bag must be opened.
Typically, the prior art bags are opened using a knife or other sharp implement. This creates the risk of injury to personnel opening bags and under certain safety regimes is prohibited. Further alternatives include using additional material to tie around the neck of the bag or placing a knot in the neck of the bag. The former solution has the disadvantage of requiring extra materials, either associated with the bag on sealing or attached to the bag, and furthermore requires a manual tying operation. The latter solution also requires a manual tying operation. Accordingly, although these two solutions remove the need for cutting implements to be used to open the bags, they are expensive to implement through the requirement for additional materials or manual operations.
In accordance with a first aspect of the present invention there is provided a method of sealing a bag comprising gripping the neck of the bag; passing the gripped portion of the bag neck around a rod approximately a complete revolution; continuing to revolve the gripped portion of the bag and moving the gripped portion axially away from the distal end of the rod until generally a further 2-300 degree revolution has been completed so that the neck of the bag is wrapped around the rod; opening a recess in the rod and placing the free end of the neck into the recess, and holding the free end in the recess whilst withdrawing the rod through the wrapped portion of the neck.
In a second aspect, there is provided a bag sealer comprising a rod, a gripping arm rotatable about the rod, preferably concentrically with the rod, the gripping arm and rod being movable relative to one another in an axial direction, the gripping arm including jaws or the like, operable to grip the neck of a bag to be fastened, and the rod including a coverable recess arranged to accept a portion of a bag neck when opened and to generally be flush with the outer diameter of the rod when closed.
An embodiment of the invention will now be described by way of example with reference to the drawings in which:
With reference to
The grab arm is rotatable about a rod 6. As drawn, the grab arm rotates concentrically with the rod but this is not essential.
With reference to
The bag may be introduced to the apparatus using conventional means although a detailed explanation is given below.
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With reference to
The rod 6 may now retract, pulling the end of the bag through the double looped portion of the neck. The double looped portion of the neck 16 is prevented from sliding back up the rod by an annular collar 18. As the rod 6 withdraws, the neck is pulled through the double looped portion 16, thus forming a knot. The bag is now sealed and may be opened by unknotting without the use of cutting tools.
It will be appreciated that the above may be implemented using pneumatic or hydraulic technology, and using components which have been well tested in a factory environment. The apparatus provides a convenient and repeatable bag sealing function and may be adjusted to suit different size bags, for example by providing a micro-controller to operate the hydraulic/pneumatic rams and by reprogramming the micro-controller.
With reference to
As the bag 8 moves beneath the apparatus, the bag is held stationary while the knotting operation is performed. The powered track 20 and conveyer 22 may then operate to move another bag beneath the apparatus so that knotting may be carried out as part of an automated sequential operation, for example on the same conveyer used to fill the bags.
Claims
1. A method of sealing a bag comprising (a) gripping a neck of the bag; (b) passing a gripped portion of the bag neck around a rod approximately a complete revolution; (c) continuing to revolve the gripped portion of the bag and moving the gripped portion axially away from a distal end of the rod until generally a further 2-300 degree revolution has been completed so that the neck of the bag is wrapped around the rod (d) opening a recess in the rod and placing a free end of the neck into the recess, and (e) holding the free end in the recess whilst withdrawing the rod through a wrapped portion of the neck.
2. A method according to claim 1, including holding an annular collar formed around the rod, generally stationary against an edge of the wrapped portion of the neck to cause the wrapped portion to be removed from the rod when the rod is withdrawn.
3. A bag sealer comprising a rod, and a gripping arm rotatable about the rod, preferably concentrically with the rod, the gripping arm and rod being movable relative to one another in an axial direction, the gripping arm including jaws operable to grip a neck of a bag to be fastened, and the rod including a coverable recess arranged to accept a portion of a bag neck when opened and to generally be flush with an outer diameter of the rod when closed.
Type: Application
Filed: Jul 27, 2007
Publication Date: Oct 8, 2009
Inventor: William John Bailey (Stow on the Wold)
Application Number: 12/375,429
International Classification: B65B 7/02 (20060101); B65B 7/12 (20060101);