IE44297B1 - An automatic tying machine - Google Patents

Abstract

There is disclosed a machine for automatically forming a knot around an article such as a sausage and the like. The object to be tied is introduced into aligned tubes, and a thread, a cord or the like is interlaced around the tubes by the following operations: rotation and translation of a cord pressing member which first presses and then releases the cord, a forward and back movement of a member for retaining the cord, and the forward and back motion of a separator. The tightening of the cord is brought about by the action of a gripper carried by the separator and by a means for tensioning the cord, while the cord is deposited upon the object by reason of the separation of the tubes. A cutting means which operates at the end of the cycle cuts off the end of the cord upstream of the knot. The invention can be used to tie a number of different objects as well as sausages.

Description

This invention relates to a machine for automatically tying sausages or other articles.

At present, there is no machine capable of performing such a tying operation automatically. It is done by hand.

The present invention provides a machine for tying-off sausages or other articles, comprising an article-locating tube for accommodating an article to be tied along the axial length of the said tube, the said tube having two sections which are mounted for relative axial approach and recession, cord manipulating members which function automatically to wind a length of cord or other tie member to form a loose clove hitch around the tube when the said sections of the tube are contiguous with each other, and to pull the knot tight around an article to be tied in the said tube when the said sections of the tube are separated from each other.

The machine of the invention is preferably constructed to perform tying operations on successive lengths of cord drawn from a supply spool and to ..cut the cord automatically between successive knots.

The machine is preferably constructed to operate cyclically for performing tying operations repetitively on successive lengths of cord drawn from a supply spool and to cut the cord automatically between successive knots. - 2 44297 In a machine wherein the knots are formed at the meeting zone of separate sections of a sausage-locating tube as above referred to, the tightening of a knot may be followed automatically by relative approach of the tube sections into abutting relationship and then by commencement of the formation of a further knot, prior to the cutting of the cord to release the previously tied sausage or other article.

The cord-manipulating mechanism preferably comprises a cord gripper, an actuating mechanism for displacing such gripper through an operating cycle comprising bodily rotations around the article-locating tube and components of motion parallel with the axis of such tube, and stop members which are displaceable towards and away from the tube in timed relationship to the rotational and axial components of motion of the cord gripper to provide stop faces against which the cord is pulled by the line gripper to maintain two convolutions in spaced relationship along the locating tube preparatory to the threading of an end portion of the cord beneath the reach of cord extending between such convolutions to achieve a knot-locking action when the knot is tightened. The aforesaid threading can be achieved by providing a cord take-up holder which is displaceable between said connecting reach of cord and the guide tube and operates to take over the cord gripping function from the cord gripper.

The cord-manipulating mechanism preferably comprises a cord clamp means which is displaceable between said joining reach of cord and the guide tube and operates to take over the cord gripping function from the cord gripper so that the latter can release its grip.

The machine is preferably constructed with cutting means which cuts the cord or other tie member at distances from the tied knot such that the cord has two free ends and preferably means is provided whereby the length of such free ends can be adjusted (preferably between 5 and 30 cms).

Preferably the machine according to the invention is pneumatically operated, the movements thereof preferably being derived from a pneumaticallyoperated reciprocating member. - 3 4 4 2 9'' By means of machines according to the invention as hereinbefore referred to, sausages which have been automatically filled by a filling machine (e.g. a so-called Poussoir filling machine) can be automatically tied off at the speed at vzhich the filling machine operates.

While the machines have been referred to as machines for tying off sausages, machines having the features which characterise the present invention can be used for tying operations for other purposes.

Reference is now made to an embodiment of the invention, selected by way of example, which is illustrated in the accompanying diagrammatic drawings, in which: Figures 1 to 4 illustrate stages in the operating cycle of the machine; Figure 5 is a sectional elevation on line B-B of Figure 6 of principal parts of the cord-manipulating mechanism wholly pneumatically operated; Figure 6 is a cross-section on line A-A in Figure 5; and Figure 7 is a plan view of a detail of the said mechanism.

Reference is firstly made to Figures 5 to 7 representing principal structural features of the machine.

A frame 20 supports a sausage-locating tube 1. The tube has an axially displaceable end section 2. These tvzo coaxial tube sections can be moved apart by means of miniature cylinders 3. Two openings 21 in the end section 2 are provided for the passage of a cord.

A rotor 5 rotates about the tube 1, being supported at its periphery, for example by rollers 7. The rotor is rotated by reciprocal movement of a pneumatically-operated rack 9 engaging a pinion integral with a gear wheel 8 engaging the said rotor 6.

A cord gripper in the form of a single-acting plunger 4 is carried by the rotor 6. This cord gripper is bodily axially movable (as suggested by the broken lines in Figure 6) by a double-acting ram 5 which is also housed in the rotor 6. - 4 44397 When the Internal diameter of the tube 1 is small the cord gripper 4 and the ram 5 can be supplied with compressed air by a rotary joint. If the diameter is large this supply is effected by means of three flexible pipes within a flexible sleeve 12. This sleeve is wound onto and unwound from drums (not shown) coupled to the rotor 6 and the gear wheel 8.

Rotation of the rotor 6 can be stopped in a predetermined position by a pneumatically actuated stop 16.

A first stop member 15 is radially displaceable into contact with a front end portion of the tube 1. When this stop is retracted the cord gripper 4 can pass by the stop, even when the gripper is in its advanced (broken line) position.

A second stop member 13 carries a pneumatically operated cord clamp 14. This second stop is movable along a path which is tangential to the outside surface of the tube 1. When the rotor 6 is in the indexing position (the position shown in Figure 5) this path is also tangential to the spindle of the cord-gripping plunger 4. An opening in the plunger allows the separator 13 to pass.

The cord clamp 14 on the second stop member 13 is bodily movable normally to the path of movement of the said stop member 13. When the said clamp is retracted away from the rotor 6, the clamp does not obstruct the rotating movement of the cord gripper 4 even if the second stop member 13 is in its raised position.

A pneumatic cutter 17 is provided for cutting off a cord located between its two blades.

Cord from a spool is directed along annular guides. Feed of the cord may be interrupted by means of a pneumatic clamp 19 (Figure 5). Near that clamp there is a pneumatically operated piston 18 for engaging the cord.

Retraction of this piston while clamp 19 is closed causes tensioning of the cord.

Figures 1 to 4 illustrate the tying operation by the machine. The cord gripper 4 grips the cord, the gripper being in its forward position. After rotation of the rotor 6, with the cord gripper, through about 270°, the gripper is - 5 4 4 3 9 7 retracted and the first stop member 15 is displaced up to the tube 1. Once the stop member 15 has passed by, the cord gripper is advanced by means of the ram 5 and the second stop member 13 is raised. The cord gripper continues its rotation around the tube 1 and the first stop member 15 is retracted. At the end of the cycle, the cord gripper 4 passes between the jaws of the clamp 14.

The interlacing is complete. The clamp 14 closes to take hold of the cord and the cord gripper 4 opens to release the cord and is retracted.

Figure 2 shows the next stage: the object to be tied (e.g. the sausage) is now introduced into the tube 1. This generates a signal which initiates the knot-tightening operation. The tubes 1 and 2 move apart and the rotor 6 rotates in the reverse direction through 90°. The portion BI of the cord is gripped by the clamp 19. The cord-tensioning piston 18 is retracted and the second stop member 13 carrying the cord clamp 14 is retracted. The knot is thus pulled tight around the object. The stroke of the ram of the second stop member 13 defines the length of the portion B2 of the cord.

Figures 3 and 4 show the next stage: the clamps 19 and 14 are opened. The cord gripper 4 is advanced along the axis of the tube 1. The end section 2 of the tube 1 is displaced back into contact with main tube section. The openings 21 prevent the cord becoming trapped. The rotor 5 begins a new working rotation. The portion BI of the cord is drawn along by the gripper 4.

When the length of this portion between the gripper and the tightened knot is sufficient, the cord is cut by the cutter 17. The cord gripper 4 retains its hold on the portion of the cord coming from the spool. The piston 18 returns to its rest position, and the cord gripper 4 is retracted. A new cycle begins.

The length of the portion BI of the cord cut off is determined by the position of the cutter relative to the upper opening 21.

The tied object can be withdrawn manually or automatically from either end of the tube 1. If the machine is in use in a factory for curing sausages, the introduction of a sausage to be tied-off causes the preceding sausage to be ejected. - 6 4 4 2 9? When the spool of cord is changed, the free end is introduced into the guides and the openings 21 and is held by hand during the opening stage of the operation.

During the operating cycle, the rack 9 (Figure 5) and the rotor 6 drive a programme rack or slide 10. This slide includes openings which generate signals in pneumatic pick-ups 11 (Figure 6) which operate by detecting leakage of compressed air through these openings. These data are processed by conventional pneumatic logic devices. Gripping instruction can be transmitted by an operator for instance by means of a radio pick-up provided with an aerial, or by means of an automatic connection to the pusher (sausage filler).

A machine as described can be used for forming a self-locking knot around any kind of object. By avoiding the use of elements subject to friction such as cams, and by employing plastics material and stainless metal, the machine can be made particularly suitable for use in environments where it would otherwise be subject to oxidation.

Claims (5)

CLAIMS.

1. A machine for tying-off sausages or other articles, comprising an article-locating tube for accommodating an article to be tied along the axial length of the said tube, the said tube having two sections which are mounted for relative axial approach and recession, cord manipulating members which function automatically to wind a length of cord or other tie member to form a loose clove hitch around the tube when the said sections of the tube are contiguous with each other, and to pull the knot tight around an article to be tied in the said tube when the said sections of the tube are separated from each other.

2. A machine according to Claim 1, which is constructed to perform tying operations on successive lengths of cord drawn from a supply spool and to cut the cord automatically between successive knots.

3. A machine according to Claim 2, wherein there is a cord-cutting mechanism which operates in timed relation to the cord-manipulating mechanism and to the approach and recession movements of said tube sections so that tightening - 7 & 4 2 S 7 of a knot is followed by relative approach of the tube sections into abutting relationship and then by commencement of formation of a further knot prior to the cutting of the cord tc release the previously tied sausage, or other article.

4. A machine according to any of Claims 1 to 3, wherein there are a cord gripper, an actuating mechanism for displacing such gripper through an operating cycle comprising bodily rotations around the article-loading tube and components of motion parallel with the axis of such tube, and stop members which are displaceable towards and away from the tube in timed relationship to the rotational and axial components of motion of the cord gripper to provide stop faces against which the cord is pulled by the cord gripper to maintain two convolutions of cord in spaced relationship along the said tube preparatory to the threading of an end portion of the cord beneath the reach of cord joining such convolutions thereby to achieve a knot-locking action when the knot is tightened. 5. A machine according to Claim 4, wherein the cord-manipulating mechanism comprises a cord clamp means which is displaceable between said joining reach of cord and the guide tube and operates to take over the cord gripping function from the cord gripper so that the latter can release its grip. 6. A machine according to any of Claims 1 to 5, comprising cutting means which cuts the cord or other tie member at distances from the tied knot such that the cord has two free ends. 7. A machine according to Claim 6, wherein means are provided whereby the length of the said free ends is adjustable. 8. An automatic machine according to any of Claims 1 to 7, which is wholly pneumatically operated. 9. A machine according to Claim 8, wherein all movements thereof are derived from a pneumatically-operated reciprocating member. 10. A machine according to Claim 8 or Claim 9, wherein all instructions for movements therein are initiated by signals initiated by pneumatic leakdetecti ng devi ces. Π. A machine according to Claim 10, wherein with the exception of a cutter blade or blades, all components are made from plastics materials or aluminium alloy. 12. A tying machine substantially as herein described and illustrated

5. In the accompanying drawings.