US 6,596,108 B2 · Web velocity modulator

Abstract

A process and apparatus related to a workstation adjacent to a traveling web including a device for intermittently performing an operation affecting the web. An important application involves ultrasonically welding multiple layers of a traveling web. First and second rollers on opposite sides of the workstation are simultaneously shifted in a direction counter to the machine direction each time a bonding force is applied. The overall running speed in the machine remains at a constant velocity due to the resultant festooning effect and thus the dwell time for bonding is increased. Thus the effective operating speed of processed having finite limits may be increased at least 33%. The first and second rollers are eccentrically rotationally mounted, respectively, on third and fourth hollow rollers which are provided with eccentrically positioned hollow cylindrical openings which, in turn, are mounted, respectively, on shafts positioned perpendicularly to the machine direction. Shifting of the rollers is effected by simultaneous rotation of the rollers. Preferably, the first and second rollers are driven synchronously in a first rotational direction and the third and fourth rollers are driven synchronously in the opposite rotational direction.

Claims24

Dependent claims

A process for intermittently performing an operation on a web traveling in a machine direction at a substantially constant velocity comprising

providing a workstation adjacent to said traveling web, said workstation including a device for performing an operation affecting said web intermittently at locations separated along said web in said machine direction,
providing first and second roller assemblies displaced from each other and located, in the machine direction, on opposite sides of said work station, said roller assemblies both being in driving contact with said traveling web,
intermittently actuating said device to perform said operation on said web at intervals spaced apart in the machine direction,
simultaneously shifting said first and second roller assemblies in a direction counter to said machine direction each time said device is actuated while maintaining the overall running speed in said machine direction at a constant velocity, whereby the dwell time is increased for each actuation of said device, and simultaneously shifting said first and second roller assemblies back in the machine direction after completion of each application of said operation.

1 more element

Apparatus for intermittently performing an operation on a web traveling in a machine direction at a substantially constant velocity comprising

a workstation adjacent to said traveling web, said workstation including a device for performing an operation affecting said web intermittently at locations separated along said web in said machine direction,
first and second roller assemblies displaced from each other and located, in the machine direction, on opposite sides of said workstation, said roller assemblies each having contact surfaces adapted to be in driving contact with said traveling web,
said first and second roller assemblies being configured for simultaneous shifting of said contact surfaces in a direction counter to said machine direction each time said device is actuated and for simultaneous movement of said first and second roller assemblies back in the machine direction after completion of each actuation of said device while maintaining the overall running speed in said machine direction at a constant velocity, whereby the dwell time is increased for each actuation of said device.

Apparatus for ultrasonically welding together a plurality of layers of a web traveling in a machine direction at a constant velocity comprising

an intermittently actuatable ultrasonic bonding device adjacent to the path of and adapted to contact said traveling web,
first and second roller assemblies displaced from each other and located, in the machine direction, on opposite sides of said ultrasonic bonding device, said roller assemblies each having contact surfaces adapted to be in driving contact with said traveling web, each of said first and second roller assemblies including a first hollow roller provided with an eccentrically positioned hollow cylindrical opening which is, in turn, mounted on a second hollow roller provided with an eccentrically positioned hollow cylindrical opening, said latter hollow cylindrical opening being rotationally mounted on a shaft positioned perpendicularly to said machine direction, movement of said contact surfaces in and opposite to the machine direction being effected by synchronously rotation of said hollow rollers, in opposite rotational directions at the same rotational velocity, each of said eccentric rollers being rotatable one full revolution during each actuation of said ultrasonic bonding device, thereby reducing the velocity of said web adjacent to said bonding device during actuation thereof while maintaining overall web running speed in said machine direction at a constant velocity.

Dependencies are inferred from the claim text.

Web velocity modulator

Life of this patent

Web velocity modulator

Life of this patent

Abstract

Claims24