Patent Application
20130305895
The present invention relates to severing or slitting an elongated film into plural ribbons each of less width than the original supply, and more particularly, to a motorized slitting apparatus adapted to facilitate replacement of circular slitting blades thereof.
Articles such as packages of beverages must typically be transported for retail distribution on pallets. The beverages may be canned, bottled, or otherwise supplied in containers for use by the ultimate consumer. Cans, bottles, and the like are typically prepared for retail sale by ganging a number of containers together. This may be accomplished by providing a plastic yoke which engages the necks of a predetermined number of individual bottles, such as six bottles, and holds these bottles together as a unit. A number of cans, bottles, or the like, again using the example of six such containers may be held together by shrink wrapping a film about these containers. Regardless of the precise nature of grouped or ganged containers, they must be transported in considerable quantities as they move through distribution channels from a factory to a retail point of sale. Contemporary practice is to load a wooden pallet with the ganged containers stacked on the pallet. Palletized ganged containers may then be efficiently transported using trucks and railway. Fork lifts may be efficiently be used at the point of loading and unloading of palletized containers.
It is an economic and practical necessity that bundling ganged containers onto a pallet be as easily and inexpensively achieved as possible. One solution to this requirement is to wrap or bundle the ganged containers in long strips or ribbons of plastic films. This is widely regarded as a desirable solution since plastic film is strong, inexpensive, easily applied to pallets bearing ganged containers, and easily removed from the pallets.
Plastic films suitable for wrapping ganged containers are available in large rolls, wherein the width of the web of film is much greater than is practical with respect to handling for purposes of wrapping individual pallets and the ganged containers stacked thereon. It then becomes desirable to slit a web of plastic film into two, three or even more distinct ribbons. Each ribbon may be easily applied to one pallet and its ganged containers. When the supply roll of plastic film is slit into a number of ribbons, an equal number of pallets may be prepared for shipment simultaneously. This promotes an economy in that commercial firms which bundle pallets may enjoy minimized costs of the film itself by purchasing a relatively lesser number of relatively large rolls of plastic film, then slitting or cutting these large rolls to desired width in their facilities. Also, the rate of production of prepared pallets may be maximized by the practice of using plural slit ribbon simultaneously in the preparation of an equal number of pallets.
This approach has served the shipping needs of distributors of palletized goods well. However, there remains one aspect of handling films which remains troublesome and relatively expensive. That is, because films are strong and are utilized in very great quantities, the customarily used slitting apparatus experiences fast wear of conventional circular blades which actually slit the film. In some bundling facilities, these blades may require sharpening or more likely replacement on a frequent basis, for example on the order of once a day. Blade replacement entails two types of expenses. One is the cost of the blades themselves. Blades are typically circular steel discs having sharp edges. The other cost is that replacement is a labor intensive operation, partially because replacement is frequently needed, but also because each replacement operation requires considerable time.
There exists within the bundling and shipping industry a need for reducing costs of blade renewal in plastic film slitting operations.
The present invention addresses the above stated need in two ways. One way is to utilize blades more durable, thereby requiring less frequent servicing. This may be done by utilizing ceramic materials rather than steel or other metallic materials. For example, the blade may be made entirely or partially from a ceramic material. The latter option may include for example coating the cutting surfaces of a blade with a suitable ceramic, such as a glassy material or a metal carbide. The coated blade may be mostly steel, which enables much of the blade to be fabricated from a relatively inexpensive material compared to the hard material used at the cutting surfaces, using conventional and relatively inexpensive fabrication techniques.
Even though utilization of hard materials for cutting surfaces extends the service life of cutting blades in slitting apparatus, it does not address the issue of the time consuming operation of replacing blades. The present invention sets forth improved slitting apparatus which expedites the process of replacing cutting blades. In this improvement, the slitting apparatus is formed with cutting blades and their associated drive elements such as motor, speed reduction gears, and rotatable shaft supporting the cutting blades, and preferably, a housing which encloses these elements, made movable between a deployed position and a service position. In the service position, the blades are more conveniently accessed, thereby greatly reducing the time required to replace the blades. This reduces direct labor to replace blades and also downtime of idled cutting apparatus.
In one implementation of the invention, the slitting apparatus may comprise stationary elements which are mounted to a frame of a machine which handles the unslit and subsequently slit film material, and a relatively movable blade assembly. The stationary elements may include mounting feet and a housing serving as a stationary supporting structure for a cam system which may then displace the movable blade assembly relative to the mounting feet. The movable blade assembly is moved by the cam system between a deployed position enabling slitting operations, and a service position facilitating blade replacement. The cam system may be operated by a manual lever.
It is an object of the invention to expedite and facilitate blade replacement in slitting apparatus having one or more rotatable slitting blades.
Another object of the invention is to employ an uncomplicated manual system to move the blade assembly between deployed and service positions.
A further object of the invention is to extend the service life of slitting blades.
It is an object of the invention to provide improved elements and arrangements thereof by apparatus for the purposes described which is inexpensive, dependable, and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.
Various objects, features, and attendant advantages of the present invention will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:
The overall purpose of the invention is diagrammatically illustrated in
Because
Referring now to
The base member 102 need not be of significant depth. Illustratively, it may comprise a structural panel or web 106, two depending mounting feet 108, 110, and sufficient structure such as trunnion bearing elements (not shown) to rotatably support a camshaft 112 on the structural web 106. The camshaft 112 bears a cam lobe 116 and a lever 118 which serves as a handle for rotating the camshaft 112. As will be explained hereinafter, the camshaft 112 is actuated by the lever to effect movement of the blade assembly 104 between the slitting position and the service position.
Design of the base member 102 depends upon the type of plastic film handling apparatus in use, proximity and orientation of a suitable rugged surface to which the mounting feet 108, 110 may be bolted or otherwise fastened, and is adapted thereto. The mounting feet 108, 110 may have bolt holes 114 through which mounting bolts (not shown) may be passed when mounting the base member 102 to the plastic film handling apparatus.
Referring specifically to
The blade housing 120 is incompletely depicted in that an upper wall which closes the interior of the blade housing 120 from above as seen in
Although not fully visible in
Referring momentarily to
Although the entire blade 136 may be fabricated entirely from ceramic materials, it may also be fabricated from a less expensive material such as steel, provided that the cutting surface 152 is fabricated from a ceramic material. Ceramic materials may include silica, metal oxides, silicon carbide, a metallic carbide such as tungsten carbide or titanium carbide, or other known hard materials such as cubic boron nitride, polycrystalline diamond, and others, or any combination of these. At a minimum, the point or edge 144 and nearby surfaces 154, 156 will be coated with the ceramic material.
As has been mentioned previously, the blade assembly 104 is movable between a slitting position and a service position. The base member 102 cooperates with the blade assembly 104 to achieve this transition. The blade assembly 104 may comprise two smooth walled fingers 158, 160 which may be received within corresponding holes 162, 164 formed in the web 106 of the base member 102. The holes 162, 164 constrain the blade assembly to move only axially with respect to the fingers 158, 160 and the holes 162, 164, these components thus serving as guide and support elements for holding the blade assembly 104 selectively in the slitting position and the service position. In the slitting position, the blade 136 mounted to the blade shaft 122 projects from the blade housing 120 sufficiently to slit a web passing thereby, as seen in
It will be appreciated that the guide and support elements constrain the blade assembly 104 to the path of travel described above, but do not themselves actually move the blade assembly 104 between the slitting and service positions. The blade assembly 104 is moved between the slitting and service positions by the camshaft 112 and cam lobe 116 when the lever 118 is manually moved.
This is illustrated in
The camshaft 112, its associated handle 118 and cam lobe 116, and the yoke 168 may be regarded as a manual shifting element disposed to move the blade assembly 104 between the slitting position and the service position.
It should be noted that the lever 118 is sufficiently long so as to project from the slitting apparatus 100 sufficiently to be exposed to manual access even should the slitting apparatus 100 be provided with a housing (not shown) which fully encloses the components of the base member 102 other than the lever 118.
It will be seen that the web 10 is maintained under tension even as it passes by the blades (again, represented by blade circumference 130). This holds the web 10 in an optimum position as the web 10 moves in the direction of the arrows A so that cutting effort imposed on the blades is minimized.
Thus the tension roller assembly 180 serves not only to hold the web 10 in an appropriate and effective position for slitting, but also provides a measure of safety in obstructing direct access to the blades.
Although described as journaled within the blade housing 1240, the tension roller assembly 180 could be supported on a bracket (not shown), and further, the bracket may be adjustable in position so as to adjust tension imposed on the web 10.
While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is to be understood that the present invention is not to be limited to the disclosed arrangements, but is intended to cover various arrangements which are included within the spirit and scope of the broadest possible interpretation of the appended claims so as to encompass all modifications and equivalent arrangements which are possible
