Patent Application
20080245032
This invention relates to the field of packaging machinery. Specifically, the present disclosure is a system for controlling the rotational movement of a die wheel in packaging machinery.
Packaging machinery for packaging food products such as cheese and meat, particularly, processed meat, such as bacon, are known in the art. In general, packaging machinery which are cam-operated are designed such that the rotating camshaft imparts rotational, horizontal and/or vertical motion to various camshaft components, i.e., cams, gears, sprockets and the like. These camshaft components, in turn, drive the various mechanical operations needed to produce a packaged food product.
One type of cam-operated food packaging machine is a rotary die wheel packaging machine. Rotary die wheel packaging machines are designed to automatically perform multiple packaging operations around a central rotating die wheel. In this machine, package forming/sealing, food loading and package dispensing operations are synchronized with and take place around a central rotating die wheel to make the finished packaged food product. In operation, a first packaging film is loaded into forming/sealing die cavities located on the central rotating die wheel. Each forming/sealing die cavity includes a peripheral edge called a die bead where hermetic seals are formed around the package. After the film is received, a film tucker assembly forces the film under film clamps where film is secured to the die, where it is then heated to a predetermined temperature to soften the film. A vacuum is applied from the backside of the die cavity facing the softened film and the film is thermoformed into the shape of the die cavity. As the die wheel advances, a food item is transferred from a loading station onto a second packaging film. The food item is then carried into the die cavity where it is sandwiched between the first and second packaging films. Next, the outer peripheral edges which extend beyond the food item are joined together during a first heat sealing operation. The seal that is formed extends around the outer peripheral edges of the die cavity or die bead and includes at least one aperture or unsealed area between the first and second packaging films. As the die wheel advances further, a chamber comes in contact with the die where the atmosphere surrounding the food item and between the packaging films is evacuated through the aperture. A second heat sealing operation is then performed to close the aperture and hermetically seal the food item within. Finally, the film between the die cavities is cut and a product picking station removes each individual package from the die wheel.
In general, rotary die wheel packaging machines are designed so that, during normal operation, the die wheel rotates is one direction, i.e., clockwise or counter-clockwise, so that each packaging operation may be synchronized to the forward direction of rotation of the die wheel. However, when power is removed to these machines, particularly after an emergency shut-down, the die wheel may respond by moving for short distances in the opposite direction. This can result in damage to mechanical components and assemblies operationally interconnected to the die wheel. For example, if the die wheel rotates backwards, the film tucker can damage the die beads by scratching or marring the surface of the die bead. A damaged die bead surface will not allow hermetic seals to be formed in the food package and, therefore, adversely affect the quality of the finished package.
It is therefore an object of the present invention to provide an assembly for controlling the rotational movement of a die wheel in packaging machinery thereby preventing damage to other mechanical components and systems operationally interconnected to the die wheel.
It is another object of the present invention to provide an assembly for limiting the counter-rotational displacement of a camshaft thereby preventing damage to other mechanical components and systems operationally interconnected to the die wheel, particularly, the die beads of a rotary die wheel packaging machine.
These and other objects of the present invention are provided by a first component operationally interconnected to both the die wheel and camshaft, and a second component physically connected to both the first component and the framework of the packaging machine wherein the second component is detachably mounted to the framework.
Although specific embodiments of the present invention will now be described with reference to the drawings, it should be understood that such embodiments are by way of example only and merely illustrative of but a small number of the many possible specific embodiments which can represent applications of the principles of the present invention.
Referring now to the drawings, wherein similar characters designate corresponding parts throughout the several views, there is illustrated a preferred embodiment of an assembly for controlling the rotational movement of a die wheel in packaging machinery according to the present invention. Referring specifically to
Second component 50 may include one or more members. In this embodiment, second component 50 includes a first linkage arm 51 and a second linkage arm 52 and is coupled to first component 20 by bolting a first end of the first linkage arm 51 to attachment arm 21 with rectangular washer 22 and bolts 23a and 23b along lines A and B. As shown, a second end of first linkage arm 51 is removably and pivotally joined to one end of second linkage arm 52 along line C with fastening means 53 in a clevis-like arrangement. Second linkage arm 52 is secured directly to framework 60 (
In addition to serving as a means for removably securing first linkage arm 51 to second linkage arm 52, fastening means 53 may also provide a means for disconnecting first linkage arm 51 from framework, 60. As such, means 53 may comprise a pin attachment mechanism, 54, which provides a means for manually disconnecting first linkage arm 51 from framework 60 (
Referring now to
In general, at least one or more cams mounted to the camshaft in die wheel packaging machines will have a non-symmetrical or irregular contour (not shown). A cam follower (not shown) will be in contact with and positioned on the cam. In operation, the cam follower engages with the leading edge of the cam contour and translates the rotary motion of the cam into oscillating horizontal and/or vertical motion. As the cam rotates with the camshaft, other machine components and systems mechanically connected to the cam follower are actuated. When power is withdrawn from the camshaft, the cam follower may continue to move in response to its relative position on the cam profile. This movement of the cam follower may, in turn, cause the die wheel to move. Movement of the die wheel may be in a clockwise or counter-clockwise direction. It will be understood that the term “counter-rotational” refers to the relative movement of the die wheel and camshaft in a direction opposite to that of normal operation.
Accordingly, assembly 10 of the present invention may control the counter-rotation of the die wheel in either a clockwise or counter-clockwise direction so that the counter-rotational displacement of camshaft 30 is 10 degrees or less relative to the axis of rotation of camshaft 30. Assembly 10 of the present invention may further control the counter-rotational movement of the die wheel in either a clockwise or counter-clockwise direction such that the counter-rotational displacement of camshaft 30 is 5 degrees or less relative to the axis of rotation of camshaft 30. Assembly 10 of the present invention may still further control the counter-rotational movement of the die wheel in either a clockwise or counter-clockwise direction such that the counter-rotational displacement of camshaft 30 is 2 degrees or less relative to the axis of rotation of camshaft 30. It is also within the scope of the present invention that assembly 10 may be used to manually rotate camshaft 30 in either a clockwise or counter-clockwise direction when second component 50 or a portion thereof, is disconnected from framework 60 (
Turning now to
It is important to note that while this preferred embodiment shows first component 20 mounted to camshaft 30, it is within the scope of the present invention that first component 20 may be directly mounted to and actuated by die wheel 40 (see
In
It will be apparent to those skilled in the art that modifications and additions can be made to the various embodiments described above, without departing from the true scope and spirit of the present invention. It should be understood that this invention is not intended to be unduly limited by the illustrative embodiments set forth herein and that such embodiments are presented by way of example only with the scope of the invention intended to be limited only by the claims set forth herein as follows.
