The present invention applies to apparatus and method for opening envelopes and, more particularly, to improved method and apparatus for handling an envelope to effect opening thereof on three sides.
The volume of mail being handled in the United States is increasing every year at an alarming rate. Many companies, such are credit card companies and oil companies, receive literally thousands of pieces of mail daily. Such companies employ large numbers of people in departments whose only function is to simply open the envelopes and dispatch the contents thereof to the proper departments.
Where companies receive extremely large amounts of mail on a daily basis, even a delay of one day in opening the mail can create very serious problems and be quite costly as well. For example, where financial institutions such as credit card companies and utility companies are involved, a delay in processing the mail thus resulting in a one day's delay in depositing the checks can result in a very substantial loss of interest on such an amount even for one day. Accordingly, the need for a quick and efficient mail opening machine in such instances has become paramount.
Over the past few years, various attempts have been made to design and develop equipment which will mechanically open the mail. Until now, all of these devices have been of a type which essentially open one edge of the envelope. This is accomplished by such means as slitters, abraders, or cutters which engage one side of the envelope.
Onesided envelope openers have not been altogether satisfactory. The primary problem of onesided envelope openers is that the contents are still within the envelope at the time they reach the sorting personnel. Accordingly, the sorting personnel must still expend the time of expanding the panels of the envelope and removing the contents from the envelope. This represents but small saving of time over having the same personnel actually open the one side of the envelope themselves. Additionally, the onesided envelope openers do not dispose of the problem of unobserved contents remaining in the envelope which are not removed. Accordingly, candleing devices and the like are often necessary to insure that all of the contents have been removed.
The desirable form of envelope opener is one which will open the envelope on three sides and lay back both panels of the envelope completely and fully exposing the entire contents of the envelope. An envelope opened in this manner requires the operator only to merely pick up the contents rather than have to fumble with the envelope opened on one side to remove the contents. Additionally, the chances of missed contents become nil when an envelope is opened in this manner.
The problems encountered in the design and operation of a practical three sided envelope opener are significantly greater than that involving the opening of only one side. Three such major problems encountered are firstly, the method of opening or treating the edges of the envelope, secondly, the method and apparatus for handling the envelope by which three edges thereof can be exposed for opening and, thirdly, the manner in which the panels of the envelope themselves are laid back to expose the contents.
As regards the method of opening employed in a three sided opener, a design consideration must be made as to whether or not the three edges will be completely severed and opened initially or merely weakened and opened simultaneously at a final point in the operation. It has been found, in most instances, it is preferable to only weaken the edges of the envelope rather than completely sever and open them during the initial stages. In this manner, loose contents such as coins and credit cards will be retained within the confines of the envelope even though weakened until the final opening operation.
One method which has been found very satisfactory for weakening the edges of the envelope without completely opening them in the preliminary stages is the application of heat to the edges by convection or radiation. Such methods and apparatus for accomplishing this are disclosed in U.S. Pat. No. 3,590,548 and in U.S. application Ser. No. 74,060 filed Sept. 21, 1970 now U.S. Pat. No. 3,875,722.
As more fully explained in the aforementioned U.S. Patent and application, the application of heat to the edges of the envelope tends to dry out the fibers in the immediate vicinity of the edge in a process known as carbonization thus weakening the edges permitting their easy serverance by the application of forces at a later stage. This method is one of the methods employed in the envelope opening apparatus of the present invention. However, other methods of weakening the edges may also be employed as hereinafter described.
The method and apparatus for handling the envelope to treat three sides thereof also presents many problems. One consideration is whether or not to simultaneously treat all three sides of the envelope. Since envelopes are of varying sizes, simultaneous treatment becomes an extremely difficult problem unless a machine is designed to handle only a given size of envelope.
It has been found that, from a practical standpoint, the sides of the envelope must be treated in separate stages. This means that the envelope must be reorientated to a proper position for opening of the respective sides. The reorientation of the envelope presents many problems of handling. Apparatus has been proposed whereby the envelope is rotated from one edge to its second edge and then to a third edge to sequentially present the edges for treatment. However, this apparatus is extremely complex, cumbersome and slow in operation. Various other methods have been tried such as ones involving devices which must reciprocate in their handling of the envelope. Such devices are inherently slow and as such become unsatisfactory.
Lastly, the apparatus which actually effects the separation of the panels themselves involves many design difficulties. One such problem is the presence of stiff members such as coins or cards in the envelope. The opening apparatus must be capable of standing passage of such elements through the machine and also handling such elements without scattering them upon opening them. Such devices as brakes which will shear back one of the panels of the envelope have been proposed. These devices will operate satisfactorily, however, the timing and roller pressures become critical and varying envelope thicknesses may become a problem in their operation.