The present invention is directed to a vacuum support device and method for the pickup, support, manipulation, transfer and/or delivery of a flexible sheet of material without wrinkling, folding or creasing the material.
Various assemblies and methods have been employed in the past for the support and transfer of a sheet of material from one location to another. In many of these a vacuum has been employed in the pickup of the sheet of material to hold and support the material and transfer and deliver it to a different location. For example, in prior labeling assemblies a vacuum has been employed to lift a label from a holder or magazine containing a stack of labels and transfer the label either to a container itself or to a mold in which the label is to be applied to a container upon molding of the container.
Some of these support and transfer assemblies have employed vacuum support and transfer heads or manifolds in which a vacuum is drawn on a face on the head or manifold to draw the flexible sheet toward the head and hold it on the face. For example, in Priest et al. U.S. Pat. No. 4,049,484 a vacuum head is disclosed which has a face of polyurethane foam rubber together with at least one base to support the porous polyurethane foam rubber face. However, the base is generally solid in nature and has spaced passages therethrough to communicate the vacuum in the cavity of the head to the porous layer at only spaced locations on the porous layer.
Laverriere U.S. Pat. No. 4,389,064 also discloses a gripping head having a face of porous material through which a vacuum grips and holds the sheet of material to be manipulated. However, the principal vacuum or suction is exposed to the face through spaced passages through the porous material to the sheet of material to be picked up and held, and the suction or vacuum is further channeled by spaced openings through a base plate which communicate the vacuum in the cavity of the head to the spaced passages through the porous material.
Due to the non-uniform and generally localized application of suction to the sheet material which is to be picked up, supported, manipulated, transferred and/or delivered because of these spaced passages, the aforementioned gripping and/or transfer heads are not suitable for use for the pickup, support, manipulation, transfer and/or delivery of thin flexible sheets of material which are subject to wrinkling, folding or creasing.
It has been discovered in the present invention that where such flexible sheets of materials which are subject to wrinkling, folding and/or creasing are to be picked up, supported, manipulated, transferred and/or delivered, this can be successfully done without such wrinkling, folding and/or creasing. In the present invention, a vacuum is drawn through a sheet of porous material which has a plurality of fine pores extending through the porous material and in which the pores are profusely and uniformly distributed substantially over an area of the sheet of porous material which area is at least substantially of the same size and shape as the flexible sheet of material which is to be picked up, supported, manipulated, transferred and/or delivered thereon so that the entire area of the flexible sheet of material which is to be transferred is uniformly exposed to the pores and the vacuum. In the assembly and method of the present invention there is also a substantial absence of any impairment of communication of the vacuum to the pores of the porous sheet of material. In such assembly and method the vacuum uniformly holds the flexible sheet of material which is to be picked up, supported, manipulated, transferred and/or delivered without folding, wrinkling or creasing of the flexible sheet of material.
In one principal aspect of the present invention, a transfer assembly for transferring a flexible sheet of material which is subject to wrinkling, folding and/or creasing comprises a vacuum manifold having a cavity and which is adapted to be connected to an evacuation source for drawing a vacuum on the cavity of the manifold, and an opening on the manifold of a given size and shape and communicating with the cavity. A sheet of porous material for supporting the flexible sheet of material for transfer thereon has a size and shape at least substantially the same as the given size and shape of the opening and covers the opening. The sheet of porous material has a plurality of fine pores extending therethrough, the pores being profusely and uniformly distributed substantially entirely over an area of the sheet of porous material which area is at least substantially of the same size and shape as the flexible sheet of material which is to be transferred thereon, whereby substantially the entire area of the flexible sheet of material which is to be transferred is exposed to the pores. The pores of the sheet of porous material which covers the opening are subjected to the vacuum in the manifold cavity and in the substantial absence of impairment of communication of the vacuum to the pores to uniformly pickup and hold the flexible sheet of material for transfer without folding, wrinkling or creasing of the flexible sheet of material.
In another principal aspect of the present invention, a method of moving a flexible sheet of material which is subject to wrinkling, folding and/or creasing, comprises providing a vacuum manifold having a cavity, an opening of a given size and shape which communicates with the cavity, and a sheet of porous material for supporting the flexible sheet of material thereon which is to be moved. The porous material has a size and shape at least substantially the same as the given size and shape of the manifold opening and covers the opening, and has a plurality of fine pores extending therethrough. The pores are profusely and uniformly distributed substantially entirely over an area of the sheet of porous material which area is at least of substantially of the same size and shape as the flexible sheet of material which is to be moved, whereby substantially the entire flexible sheet of material which is to be moved is exposed to the pores. The manifold is moved into overlying relationship to the flexible sheet of material which is to be moved, and a vacuum is drawn on the cavity to move the flexible sheet of material which is to be moved to the porous sheet of material and hold it thereon in the substantial absence of impairment of communication of the vacuum to the pores to uniformly pickup and hold the flexible sheet of material on the sheet of porous material without folding, wrinkling or creasing of the flexible sheet of material.
In still another principal aspect of the present invention, the transfer assembly and method includes a substantially rigid support adjacent the opening and between the sheet of porous material and the cavity, and the support has small openings profusely and uniformly distributed thereon to support the sheet of porous material in the absence of substantial impairment of communication of the vacuum between the cavity and the pores of the sheet of porous material.
In still another principal aspect of the present invention, in the transfer assembly and method the support has a size and shape at least substantially the same as the opening.
In still another principal aspect of the present invention, in the transfer assembly and method the support comprises a mesh sheet.
In still another principal aspect of the present invention, in the transfer assembly and method the sheet of porous material is selected from the group consisting essentially of a non-woven fibrous material, a woven material and/or a foamed material.
In still another principal aspect of the present invention, in the transfer assembly and method the sheet of porous material is curved.
In still another principal aspect of the present invention, the transfer assembly and method the sheet of porous material is substantially flat.
In still another principal aspect of the present invention, in the transfer assembly and method a pickup station includes a holder which holds a supply of a plurality of the flexible sheets of material which are subject to wrinkling, folding and/or creasing, and a receiving station receives at least one of the flexible sheets of material from the holder. A delivery mechanism moves the manifold between a first position in which the manifold removes at least one of the flexible sheets of material from the holder by drawing the flexible sheet of material against the sheet of porous material, and a second position in which the manifold positions the removed flexible sheet of material at the receiving station.
In still another principal aspect of the present invention, in the transfer assembly and method the flexible sheets of material are labels.
In still another principal aspect of the present invention, in the transfer assembly and method the receiving station contains a container and the label is applied to the container.
In still another principal aspect of the present invention, in the transfer assembly and method the receiving station is a container mold, and the label is positioned in the container mold to be applied to the container upon molding of the container in the mold.
These and other objects, features and advantages of the present invention will be more clearly understood upon consideration of the following detailed description.
In the course of this description, reference will frequently be made to the attached drawing in which:
With particular reference to
The opening 20 is of a given size and shape and is covered by a sheet of porous material 22 which also has a size and shape at least substantially the same as the given size and shape of the opening so that it covers the opening. The sheet of porous material 22 includes many fine pores 24 as shown in
Although the area x, y containing the pores of the sheet of porous material is shown in
The sheet of porous material 22 may be formed of various materials which permit the profusion and uniform distribution of the fine pores over the sheet. These materials may include various fibrous non-woven materials, such as felt, or fibrous woven materials, such as textiles. The use of the term “fibrous” is not intended to be limited to organic or plant fibers, but can include fibrous metallic, ceramic or polymeric materials. The sheet of porous material 22 may also be formed of various other porous materials, such as polymeric foams, sponge metals or ceramics.
It is important in the present invention that the sheet of porous material 22 and its pores 24 are subjected to the vacuum in the manifold cavity 14 in the substantial absence of impairment of communication of the vacuum to the cavity side of the sheet of porous material. In that regard where the sheet of porous material 22 is formed of a material which has sufficient strength to support itself and maintain its shape when subjected to the vacuum, its cavity side face may be exposed directly to the vacuum in the cavity without any overlying additional support material which might otherwise impair or block the exposure to the sheet of porous material 22 and its pores 24 to the vacuum in the cavity 14. However, where the sheet of porous material 22 does not have sufficient strength to maintain its shape when exposed to the vacuum in the cavity 14, an additional support sheet 28 may be provided which is at least substantially of the same size and shape as the sheet of porous material 22 and label 26. Such support may be formed of metallic, ceramic or polymeric materials and preferably takes the form of a mesh as shown in the drawing so that it presents may small openings 29 profusely and uniformly distributed through the support thus avoiding any substantial impairment of communication of the vacuum between the cavity 14 and the pores 24 of the sheet of porous material 22.
The wide profusion and uniform distribution of the pores 24 over the sheet of porous material 22, and openings 29 of the support 28, are important in the present invention to insure that all portions of the surface of the label are evenly subjected to the vacuum to prevent wrinkling, folding or creasing of the thin, flexible labels 26. This wide profusion and uniform distribution of pores is in contrast to the vacuum heads or manifolds of the prior art as earlier mentioned in which the vacuum was communicated in a non-uniform manner to the face of the manifold by spaced passages through a porous material and/or support.
In the transfer assembly 10 shown in
The transfer assembly and method shown in
It will be appreciated that the transfer assembly and method shown in
It also will be understood that the preferred embodiments of the present invention which have been described are merely illustrative of the principles of the present invention. Numerous modifications may be made those skilled in the art without departing from the true spirit and scope of the invention.