US3799456A — Refiner plate clearance control system

Claim 1

Independent Claim 117 words

An automatic control system for maintaining constant a preset distance between opposed refining surfaces of pulp refining equipment supported on a common base, said refining surfaces being relatively adjustable toward and from one another, including actuating means for moving one of said refining surfaces toward and away from the other, sensing means for continuously producing a first signal of the actual distance between said opposed refining surfaces, means for producing a second signal representative of the desired distance between said refining surfaces, means to receive and compare said first and second signals and to respond to differences to produce a third signal arranged to energize said actuating means to restore the desired distance between said refining surfaces.

Claim 2

Dependent Claim 117 words

An automatic control system for maintaining constant a preset distance between opposed refining surfaces of pulp refining equipment supported on a common base, said refining surfaces being relatively adjustable toward and from one another, including actuating means for moving one of said refining surfaces toward and away from the other, sensing means for continuously producing a first signal of the actual distance between said opposed refining surfaces, means for producing a second signal representative of the desired distance between said refining surfaces, means to receive and compare said first and second signals and to respond to differences to produce a third signal arranged to energize said actuating means to restore the desired distance between said refining surfaces.

Claim 3

Dependent Claim 25 words

An automatic control system as in claim 1 characterized by said actuating means being arranged to function until said first and second signals become equal.

Claim 4

Dependent Claim 43 words

An automatic control system as in claim 1 characterized in that said sensing means producing said first signal is comprised of independent means for sensing the respective positions of the respective refining surfaces, the combination of which sensing means produces said first signal.

Claim 5

Dependent Claim 40 words

An automatic control system as in claim 3 characterized by one of said means sensing the position of one of said refiningsurfaces being interrelated to sense the position of the said one refining surface through movements of said common base.

Claim 6

Dependent Claim 97 words

An automatic control system as in claim 1 characterized by its application to opposed refining surfaces supported on a common base, including a support means in connection with and having a relatively neutral position in reference to said base and any distortion which might be reflected therein, further characterized by said sensing means For producing said first signal being constituted by a plurality of sensing means positioned on said neutral support to independently respond to the position of a respective one of said refining surfaces, there being means combining said independent responses to produce said first signal.

Claim 7

Dependent Claim 47 words

An automatic control system as in claim 5 characterized by said independent sensing means being respectively related to directly sense the position of one of said opposed refining surfaces and to indirectly sense the position of the other of said opposed refining surfaces through said common base.

Claim 8

Dependent Claim 67 words

An automatic control system as set forth in claim 1 characterized by its application to refiner discs presenting opposed refining surfaces supported for relative rotation upon a symmetrical base, characterized by said sensing means having means mounting the same in connection with one end of said base to respectively sense the position of said discs and said refining surfaces through support means provided therefor on said base.

Claim 9

Dependent Claim 86 words

An automatic control system as in claim 7 wherein the respective discs are each supported by a shaft rotatably mounted on said base and directed respectively to extend to opposite ends thereof and characterized in that said sensing means includes independent sensing means one of which reflects the position of one of said refining surfaces through the shaft supporting the same and another of the independent sensing means sensing the position of the other refiner surface through distortion reflected through said base during a refining operation.

Claim 10

Dependent Claim 104 words

An automatic control system as in claim 1 in a refiner installation characterized by a symmetrical base mounting centrally thereof refiner discs including said opposed refining surfaces and said discs respectively mounting to a drive shaft, characterized by a neutral support beam connected to form an extension of said base to one end thereof and in a position constituting a relatively neutral position wherein any distortion of the base has a minimal influence and said sensing means for producing said first signal being mounted on said beam to sense the position of said refining surfaces through one of said shafts and through said base.

Claim 11

Dependent Claim 53 words

An automatic control system as in claim 9 characterized by said means for continuously producing a first signal being constituted by independent sensing means one of which has a direct operative relation to one of said shafts and the other of which has an operative relation to means in connection with said base.

Claim 12

Dependent Claim 160 words

An automatic control system for maintaining constant a pre-set clearance between opposed refining surfaces of pulp refining equipment supported on a common base, said refining surfaces being relatively adjustable toward and from one another, including actuating means for moving one of said refining surfaces toward and away from the other, sensing means for continuously producing a first electrical signal the phase and amplitude of which are representative of the actual clearance between said opposed refining surfaces, means for continuously producing a second electrical signal the phase and amplitude of which are representative of the desired clearance between said opposed refining surfaces, means for receiving and comparing said first and second signals and responding to differences therein to produce a third electrical signal energizing said actuating means to move said one refining surface in a direction relatively to the other to render said first and second electrical signals equal and thereby to restore the desired clearance between said opposed refining surfaces.

Claim 13

Dependent Claim 160 words

An automatic control system for maintaining constant a pre-set clearance between opposed refining surfaces of pulp refining equipment supported on a common base, said refining surfaces being relatively adjustable toward and from one another, including actuating means for moving one of said refining surfaces toward and away from the other, sensing means for continuously producing a first electrical signal the phase and amplitude of which are representative of the actual clearance between said opposed refining surfaces, means for continuously producing a second electrical signal the phase and amplitude of which are representative of the desired clearance between said opposed refining surfaces, means for receiving and comparing said first and second signals and responding to differences therein to produce a third electrical signal energizing said actuating means to move said one refining surface in a direction relatively to the other to render said first and second electrical signals equal and thereby to restore the desired clearance between said opposed refining surfaces.

Claim 14

Dependent Claim 93 words

The structure claimed in claim 11, wherein said one refining surface is supported by a shaft rotatively mounted on said base and axially shiftable, said actuating means comprising an hydraulic cylinder having a piston with a piston rod operatively connected to said axially shiftable shaft and a servo valve to energize said hydraulic cylinder, said third signal being conveyed to said servo vaLve whereby to energize said servo valve and hence said hydraulic cylinder and to control the direction and amount of shift of said shaft and said one refining surface supported thereby.

Claim 15

Dependent Claim 41 words

The structure claimed in claim 12, wherein the source of said second electrical signal includes a potentiometer and said means for receiving and comparing said first and second electrical signals and for producing said third electrical signal comprises a differential amplifier.

Claim 16

Dependent Claim 59 words

The structure claimed in claim 13, wherein said sensing means comprises first and second linear voltage differential transformers, said first transformer sensing the position of said one of said opposed refining surfaces, said second transformer sensing the position of the other of said opposed refining surfaces, the combined outputs of said first and second providing said first electrical signal.

Claim 17

Dependent Claim 155 words

The structure claimed in claim 14, wherein said base is symmetrical, said opposed refining surfaces being located centrally of said base, said shaft supporting said one refining surface extending to a first end of said base, another shaft supporting the other one of said opposed refining surfaces being rotatively mounted on said base and extending to a second end of said base, a first bearing means affixed to said first end of said base for the said shaft supporting said one refining surface, a second bearing means affixed to said second end of said base for the shaft supporting the other of said opposed refining surfaces, said last mentioned shaft being axially non-shiftable within said second bearing, said hydraulic cylinder being mounted on said first bearing, said second transformer being connected to sense movement of said cylinder resulting from base distortion and said first transformer sensing movement of the free end of said piston rod.

Claim 18

Dependent Claim 32 words

The structure claimed in the claim 15, including support means for said first and second transformers in the form of neutral beam frame means affixed to said first end of said base.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1977-03-25	1977-09-24	1978-03-26	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1981-03-25	1981-09-24	1982-03-26	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1985-03-25	1985-09-24	1986-03-26	$7700.00	Window Closed / Lapsed

Refiner plate clearance control system

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