Corrugated sheet cutoff length adjustment apparatus

Claim 2

Apparatus for cutting sheets of a preset length from a moving continuous web of corrugated material produced by a paper corrugating machine, said apparatus having the ability to immediately change from cutting one length of sheet to cutting another length of sheet and comprising, in combination: a differential means including a rotatable cage, input and output shafts supported by said cage, and a bevel gear differential connected to said input and output shafts and carried by said cage; a ring gear drivingly connected to said paper corrugating machine and attached to said cage for imparting rotational movement to said cage; means for severing said web of corrugated material, including at least one rotatably mounted cutting cylinder carrying a cutting knife and driven by said output shaft of said differential means, to form individual sheets of said corrugated material; and means for registering said differential backward while a preselected length of corrugated material passes between said means for severing said web and for changing, upon demand, the amount of backward registration of said differential between cutting of successive sheets of corrugated material to thereby allow an immediate change from cutting one length of sheet of corrugated material to cutting a second length of sheet of corrugated material without cutting any sheets of corrugated material of an intermediate length.

Claim 3

The apparatus of claim 1, wherein said means for registering said differential backward and for changing, upon demand, the amount of backward registration of said differential between cutting of successive sheets of corrugated material comprises, in combination: rotating drive means connected to said input shaft; a pulse generator attached to said input shaft for rotation therewith for generating a representation of the degrees of rotation of said input shaft; a pulse transmitter for sensing and transmitting the pulses generated by said pulse generator; means connected to said pulse transmitter and said drive means for limiting the rotation of said drive means to a pre-selected number of pulse counts; and means connected to said rotation limiting means for activating said rotation limiting means after a sheet of corrugated material has been cut.

Claim 4

The apparatus of claim 2, wherein said means for limiting the rotation of said drive means comprises, in combination: an operator-control panel having at least two independently set values of degrees of rotation of said input shaft, the magnitude of said value corresponding directly to the length of sheet to be cut by said cutting cylinder; a switch for selecting one of said values; and an electronic control and logic unit connected to said operator-control panel and preset to allow said drive means to rotate only the number of degrees of said selected value, whereby operating said switch to select another one of said set values will cause an immediate change in the length of corrugated sheet cut by said cutting cylinder.

Claim 5

The apparatus of claim 2, wherein said means for activating said rotation limiting means comprises, in combination: a plate cam attached to said output shaft for rotation therewith; and a switch controlled by said cam and connected to said means for limiting the rotation of said drive means for turning said limiting means on after the cutting of a sheet by said cutting cylinder.

Claim 6

The apparatus of claim 2, further including means connected between said drive means and said input shaft for limiting the rotation of said drive means to a single direction.

Claim 7

The apparatus of claim 2, further including means for holding the rotational speed of said rotating drive means to a preset percentage of the speed of said moving web of corrugated material.

Claim 8

In a corrugated paperboard manufacturing process, wherein a continuous moving web of corrugated material is severed to form individual sheets by a rotating knife-carrying cylinder, a method for driving said knife cylinder to allow immediate changes in the length of sheet cut, comprising the steps of: driving said knife cylinder with the output shaft of a bevel gear differential; driving a second cylinder covered with a resilient material mounted in opposition to said first knife cylinder at a speed proportional to the linear speed of said corrugated web; driving said differential through a line shaft rotating at a speed proportional to the linear speed of said corrugated web when said web is to be severed; registering said differential backward to retard the rotation of said knife cylinder to allow a pre-selected length of web to pass between said knife cylinder and said second cylinder before said web is severed; controlling the backward registration of said differential as a function of the number of degrees of rotation of an input shaft of said differential with an electronic logic unit; feeding one of a plurality of rotational values of said input shaft to said logic unit as a registration set point; and inter-connecting said plurality of rotational values of said input shaft and said logic unit with a multiple-pole switch, whereby any one of said values may be selected as said registration set point and changes in said set point may be made from one severed sheet to the next.

Claim 9

In a corrugated paperboard manufacturing process, wherein a continuous moving web of corrugated material is severed to form individual sheets by a rotating knife-carrying cylinder, a method for driving said knife cylinder to allow immediate changes in the length of sheet cut, comprising the steps of: driving said knife cylinder with the output shaft of a bevel gear differential; driving a second cylinder covered with a resilient material mounted in opposition to said first knife cylinder at a speed proportional to the linear speed of said corrugated web; driving said differential through a line shaft rotating at a speed proportional to the linear speed of said corrugated web when said web is to be severed; registering said differential backward to retard the rotation of said knife cylinder to allow a pre-selected length of web to pass between said knife cylinder and said second cylinder before said web is severed; controlling the backward registration of said differential as a function of the number of degrees of rotation of an input shaft of said differential with an electronic logic unit; feeding one of a plurality of rotational values of said input shaft to said logic unit as a registration set point; and inter-connecting said plurality of rotational values of said input shaft and said logic unit with a multiple-pole switch, whereby any one of said values may be selected as said registration set point and changes in said set point may be made from one severed sheet to the next.

Claim 10

Apparatus for cutting sheets of a preset length from a moving continuous web of corrugated material produced by a paper corrugating machine, said apparatus having the ability to immediately change from cutting one length of sheet to cutting another length of sheet, comprising, in combination: a differential means including a rotatable cage, input and output shafts supported by said cage, and a bevel gear differential connected to said input and output shafts and carried by said cage; a ring gear drivingly connected to said paper corrugating machine and attached to said cage for imparting rotational movement to said cage; means For severing said web of corrugated material, including at least one rotatably mounted cutting cylinder carrying a cutting knife and driven by said output shaft of said differential means, to form individual sheets of corrugated material; rotating drive means connected to said input shaft for registering said differential backward; control means connected to said drive means for limiting the backward registration of said drive means to allow a pre-selected length of corrugated material to pass between said means for severing said web; and switching means, connected to said control means, for changing, upon demand, the amount of backward registration of said drive means between cutting of successive sheets of corrugated material to thereby allow an immediate change from cutting one length of sheet of corrugated material to cutting a second length of sheet of corrugated material without cutting any sheets of corrugated material of an intermediate length.

Claim 11

Apparatus for cutting sheets of a preset length from a moving continuous web of corrugated material produced by a paper corrugating machine, said apparatus having the ability to immediately change from cutting one length of sheet to cutting another length of sheet, comprising, in combination: a differential means including a rotatable cage, input and output shafts supported by said cage, and a bevel gear differential connected to said input and output shafts and carried by said cage; a ring gear drivingly connected to said paper corrugating machine and attached to said cage for imparting rotational movement to said cage; means For severing said web of corrugated material, including at least one rotatably mounted cutting cylinder carrying a cutting knife and driven by said output shaft of said differential means, to form individual sheets of corrugated material; rotating drive means connected to said input shaft for registering said differential backward; control means connected to said drive means for limiting the backward registration of said drive means to allow a pre-selected length of corrugated material to pass between said means for severing said web; and switching means, connected to said control means, for changing, upon demand, the amount of backward registration of said drive means between cutting of successive sheets of corrugated material to thereby allow an immediate change from cutting one length of sheet of corrugated material to cutting a second length of sheet of corrugated material without cutting any sheets of corrugated material of an intermediate length.