Fluid self-balancing rotary screen tensioning mount

Claim 2

A printing head for use on a rotary screen printing machine comprising: a printing head mount including opposed yoke means, a cylindrical printing screen, end rings connected to the opposed ends of said screen, a driving gear connected to at least one of said end rings, a thrust mounting bearing for rotatably supporting the opposed ends of said screen on said yoke means, and a pair of fluid actuated piston and cylinder assemblies mounted on each of said yoke means, and means interconnecting the cylinders of the respective pair of piston and cylinder assemblies to permit the free flow of fluid between the respective connected cylinders for maintaining a self-balancing axial thrust on each of said thrust mounting bearings and associated screen ends.

Claim 3

The invention as defined in claim 1 where each of said piston and cylinder assemblies include, a cylinder defining a fluid chamber, a piston slidably mounted in said cylinder, said means interconnecting the cylinder of said respective pair of piston and cylinder assemblies comprising a conduit interconnecting the fluid chambers of said connected cylinders. and means for maintaining a fluid pressure on said connected chambers.

Claim 4

The invention as defined in claim 2 wherein said pistons and associated thrust bearings have complementary mating surfaces.

Claim 5

The invention as defined in claim 2 wherein the piston of one of said pair of assemblies has a conical projecting end portion and the piston of the other of said pair of assemblies has a projecting wedge shaped end portion, and associated bearing members have complementary recessed portions for receiving said respective conical and wedge shaped projecting piston end portions.

Claim 6

The invention as defined in claim 2 wherein one pair of said piston and cylinder assemblies includes means for effecting a retraction of the pistons within their respective cylinders to facilitate release of the associated screen end.

Claim 7

The invention as defined in claim 5 wherein said latter means includes a spring acting on each of said pistons of said one pair of said piston and cylinder assemblies normally biasing the respective pistons in a direction opposite to the fluid pressure acting thereon.

Claim 8

The invention as defined in claim 6 and including a valve means disposed in said conduit of said one pair of piston and cylinder assemblies for releasing the fluid pressure on said one pair of pistons.

Claim 9

The invention as defined in claim 2 and including a valve means operatively connected to said conduit interconnecting the fluid chambers of said one pair of piston and cylinder assemblies for releasing the fluid pressure acting on the piston thereof upon the opening of said valve means.

Claim 10

The invention as defined in claim 8 wherein said means for maintaining fluid pressure on the piston of said one pair of piston and cylinder assemblies includes a fluid pump.

Claim 11

The invention as defined in claim 9 wherein the means for maintaining fluid pressure on the other pair of said piston and cylinder assemblies includes a manually operated pressure pump.

Claim 12

The invention as defined in claim 1 wherein at least one pair of said piston and cylinder assemblies includes a spring in each assembly of said pair of assemblies for normally biasing the respective pistons thereof against the fluid pressure acting thereon.

Claim 13

The invention as defined in claim 1 wherein said thrust mounting bearing comprises a radial thrust mounting bearing.

Claim 14

The invention as defined in claim 12 wherein said radial thrust bearing includ a concentrically nested inner and outer bearing race circumscribing the opposed end portions of said screen, rolling bearings disposed between said concentrically disposed races and sealing means disposed between said races to seal said bearings therebetween.

Claim 15

The invention as defined in claim 13 wherein said bearing races are provided with complementary angularly disposed seating faces for accommodating said rolling bearings therebetween.

Claim 16

A printing head for use in a rotary screen printing machine comprising: a printing head having a pair of spaced apart yoke means, each of said yoke means including a base member defining a substantially V-shaped screen mount, and a slide support slideably disposed on each leg of said V-shaped screen mount whereby said slide support may be adjustably disposed along said V-shaped mount to provide an adjustable yoke means for accommodating screens of varying sizes, a cylindrical printing screen, end rings connected to the respective ends of said screen, a thrust bearing member having an opening for receiving the end rings for rotatably supporting the end rings on corresponding slide supports of said yoke means, a bearing means interposed between said thrust bearing member and said screen end rings, a driving gear ring connected to at least one end ring of said screen to effect the drive of said screen, and fluid actuating means on said slide supports for imposing a thrust loading on each end of said screen to maintain said screen in tension, said fluid actuating means including a cylinder mounted on each of said slide supports, each of said cylinders defining a fluid chamber, a piston slideably disposed in each of said cylinders, conduit means interconnecting the fluid chambers of said cylinders supported on the respective legs of slide supports to permit the free flow of fluid between the connected fluid chambers, said piston projecting against said thrust bearing members under fluid pressure for maintaining a balanced thrust loading on the respective bearing members and associated screen end portions, means for maintaining a fluid pressure on said pistons.

Claim 17

A printing head for use in a rotary screen printing machine comprising: a printing head having a pair of spaced apart yoke means, each of said yoke means including a base member defining a substantially V-shaped screen mount, and a slide support slideably disposed on each leg of said V-shaped screen mount whereby said slide support may be adjustably disposed along said V-shaped mount to provide an adjustable yoke means for accommodating screens of varying sizes, a cylindrical printing screen, end rings connected to the respective ends of said screen, a thrust bearing member having an opening for receiving the end rings for rotatably supporting the end rings on corresponding slide supports of said yoke means, a bearing means interposed between said thrust bearing member and said screen end rings, a driving gear ring connected to at least one end ring of said screen to effect the drive of said screen, and fluid actuating means on said slide supports for imposing a thrust loading on each end of said screen to maintain said screen in tension, said fluid actuating means including a cylinder mounted on each of said slide supports, each of said cylinders defining a fluid chamber, a piston slideably disposed in each of said cylinders, conduit means interconnecting the fluid chambers of said cylinders supported on the respective legs of slide supports to permit the free flow of fluid between the connected fluid chambers, said piston projecting against said thrust bearing members under fluid pressure for maintaining a balanced thrust loading on the respective bearing members and associated screen end portions, means for maintaining a fluid pressure on said pistons.