US3795121A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Helical shelf for rotary inclined processing tank
Assignee: Canada Barrells and Kegs Ltd
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Filing: 1973-02-26
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Granted: 1974-03-05
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Expires: 1993-02-26
Abstract
Abstract A pair of helically shaped flat shelves each having a first rearward curving lip along a portion of its inner edge located in a generally cylindrical rotatable processing tank, such as a hide processing tank, with an axis of rotation inclined to the horizontal. Rotation of the tank about the axis of rotation causes the shelves to move thereby producing improved circulation of the hides in suspension in processing fluid in the tank. The circulating motion of the hides is down the walls of the tank along the shelves towards the rear and up the central portion of the tank towards the front. In addition to this improved circulation, the hides are also lifted up the walls by the motion of the shelves and dropped back into the processing fluid, thereby subjecting the hides to improved ''''scudding'''' action. This lifting and dropping action is dependent upon lips which curve from the inner edge of the shelves towards the rear of the tank. The degree of lifting action is also determined by the pitch of the shelves as well as the angle of inclination of the axis of rotation, and therefore the pitch of the shelves is varied in three different zones along the length of the tank to produce different lifting action in each zone. The junctions of the shelves with the rear end of the tank are filled to form smooth sloping surfaces and a deflection barrier provided across the rear end of the tank between the junctions to provide improved circulation of the hides in the tank. The shelves may also each have a second forward curving lip extending a second portion of its inner edge through a truncated cone shaped body portion leading to a front opening. Processed hides may be removed from the tank by reversing the direction of rotation of the tank. The hides are retained on the shelves by the second curved lips as they are carried forwardly along the shelves to the front opening.
Inventors
- 👤 F Cressman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 15:00
CPC Classifications
C; C14; C14B; C14B1/00; C14B2700/00; C14B2700/27
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
111 words
In a rotatable processing tank of molded fiberglass resin laminate located with its axis of rotation inclined to the horizontal and having a closed lower rear end, a main body portion with a cylindrically shaped wall, and an open upper front end, a helically shaped shelf extending Along at least a portion of the inside surface of the wall of the main body portion, said shelf having an outer and inner edge, the outer edge being rigidly secured to the said cylindrically shaped wall, and a first curved lip extending along at least a first portion of its inner edge, said first lip curving towards the rear end of the tank.
Claim 2
Dependent Claim
111 words
In a rotatable processing tank of molded fiberglass resin laminate located with its axis of rotation inclined to the horizontal and having a closed lower rear end, a main body portion with a cylindrically shaped wall, and an open upper front end, a helically shaped shelf extending Along at least a portion of the inside surface of the wall of the main body portion, said shelf having an outer and inner edge, the outer edge being rigidly secured to the said cylindrically shaped wall, and a first curved lip extending along at least a first portion of its inner edge, said first lip curving towards the rear end of the tank.
Claim 3
Dependent Claim
75 words
In a processing tank according to claim 1, a further identical shelf rigidly secured to the said wall to provide a pair of helically shaped shelves equally spaced around the inside surface of the wall of the main body portion, each shelf extending from the closed rear end to the open front end of the tank, each shelf being rigidly secured along its outer edge to the cylindrically shaped wall of the main body portion.
Claim 4
Dependent Claim
57 words
In a processing tank according to claim 1, a second curved lip extending along a second front portion of the inner edge of the helically shaped shelf, said second lip curving towards the front end of the tank, said shelf having a gradually curved transition lip portion connecting the first curved lip to the second curved lip.
Claim 5
Dependent Claim
74 words
In a processing tank according to claim 3, a further identical shelf rigidly secured to said wall to provide a pair of helically shaped shelves euqally spaced around the inside surface of the wall of the main body portion, each shelf extending from the closed rear end to the open front end of the tank, each shelf being rigidly secured along its outer edge to the cylindrically shaped wall of the main body portion.
Claim 6
Dependent Claim
156 words
In a rotatable processing tank of molded fiberglass resin laminate located with its axis of rotation inclined to the horizontal and having a closed lower rear end, a main body portion with a cylindrically shaped wall extending from the rear end, a truncated cone body portion having a cone shaped wall extending from the main body portion, and an open upper front end defined by the cone shaped body portion to be smaller in diameter than the main body portion, a pair of helically shaped shelves equally spaced around and extending along at least a portion of the inside surface of the wall of the main body portion, each shelf having an outer and inner edge, the outer edge being rigidly secured to the said cylindrically shaped wall, and a first curved lip extending along at least a first portion of its inner edge, each said first lip curving towards the rear end of the tank.
Claim 7
Dependent Claim
156 words
In a rotatable processing tank of molded fiberglass resin laminate located with its axis of rotation inclined to the horizontal and having a closed lower rear end, a main body portion with a cylindrically shaped wall extending from the rear end, a truncated cone body portion having a cone shaped wall extending from the main body portion, and an open upper front end defined by the cone shaped body portion to be smaller in diameter than the main body portion, a pair of helically shaped shelves equally spaced around and extending along at least a portion of the inside surface of the wall of the main body portion, each shelf having an outer and inner edge, the outer edge being rigidly secured to the said cylindrically shaped wall, and a first curved lip extending along at least a first portion of its inner edge, each said first lip curving towards the rear end of the tank.
Claim 8
Dependent Claim
58 words
A pair of helically shaped shelves as claimed in claim 5, each shelf extending from the closed rear end to the open front end of the tank, each shelf being rigidly secured along its outer edge to the cylindrically shaped wall of the main body portion and to the cone shaped wall of the cone shaped body portion.
Claim 9
Dependent Claim
131 words
A pair of helically shaped shelves as claimed in claim 5, each shelf extending from the closed rear end to the open front end of the tank, each shelf being formed of molded fiberglass resin laminate and bonded along its outer edge to the cylindrically shaped wall of the main body portion and to the cone shaped wall of the cone shaped body portion by a resin-bonded fiberglass laminate, each shelf projecting inward, in transverse section, substantially perpendicular to the cylindrical wall of the main body portion of the tank, each shelf forming a junction with the closed rear end of the tank, each junction being filled to provide relatively smooth sloping surfaces between the respective shelf, the lower end of the tank and the wall of the main body portion.
Claim 10
Dependent Claim
73 words
A pair of helically shaped shelves as claimed in claim 6, each shelf extending to form a junction with the closed rear end of the tank, the tank also having a deflection barrier projecting inward from the rear end of the tank to bisect the rear end substantially perpendicular to an imaginary straight line extending between the said two junctions, the deflection barrier having a cross-section in the shape of an inverted V.
Claim 11
Dependent Claim
37 words
A pair of helically shaped shelves as claimed in claim 6 each shelf having a helix angle witH respect to the longitudinal axis of the tank which increases in steps towards the front end of the drum.
Claim 12
Dependent Claim
39 words
A pair of helically shaped shelves as claimed in claim 6 the tank also having a continuous perforated wash ring located adjacent the wall and the rear end of the tank, the wash ring being substantially rectangular in cross-section.
Claim 13
Dependent Claim
60 words
A pair of helically shaped shelves as claimed in claim 6, each shelf having a second curved lip extending along a second front portion of its inner edge, each said second curved lip curving towards the front end of the tank, each shelf having a gradually curved transition lip portion connecting the first curved lip to the second curved lip.
Claim 14
Dependent Claim
33 words
A pair of helically shaped shelves as claimed in claim 11 wherein each transition lip portion is located substantially adjacent the junction between the main body portion and the truncated cone body portion.
Claim 15
Dependent Claim
31 words
A pair of helically shaped shelves as claimed in claim 11 wherein the first lip projects inwardly from the outer edge of the shelf a greater distance than the second lip.
Claim 16
Dependent Claim
42 words
A pair of helically shaped shelves as claimed in claim 11 each shelf extending to form a junction with the closed rear end of the tank, the tank also having a deflection barrier projecting inwardly from the rear end of the tank.
Claim 17
Dependent Claim
73 words
A pair of helically shaped shelves as claimed in claim 11, each shelf extending to form a junction with the closed rear end of the tank, the tank also having a deflection barrier projecting inward from the rear end of the tank to bisect the rear end substantially perpendicular to an imaginary straight line extending between the said two junctions, the deflection barrier having a cross-section in the shape of an inverted V.
Claim 18
Dependent Claim
78 words
A pair of helically shaped shelves as claimed in claim 11 each shelf being formed of molded fiberglass resin laminate and bonded to the cylindrically shaped wall of the main body portion by a resin-bonded fiberglass laminate, each shelf forming a junction with the closed rear end of the tank, each junction being filled to provide relatively smooth sloping surfaces between the respective shelf, the lower end of the tank and the wall of the main body portion.
Claim 19
Dependent Claim
37 words
A pair of helically shaped shelves as claimed in claim 11, each shelf having a helix angle with respect to the longitudinal axis of the tank which increases in steps towards the front end of the drum.
Claim 20
Dependent Claim
80 words
A pair of helically shaped shelves as claimed in claim 11 each shelf having a helix angle with respect to the longitudinal axis of the tank which increases in first, second and third steps towards the front end of the drum, first, second and third steps corresponding to first, second and third zones of the tank, the first zone being adjacent the rear end of the tank and the third zone corresponding to the cone body portion of the tank.
Claim 21
Dependent Claim
39 words
A pair of helically shaped shelves as claimed in claim 11, the tank also having a continuous perforated wash ring located adjacent the wall and the rear end of the tank, the wash ring being substantially rectangular in cross-section.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-03-04 | 1977-09-03 | 1978-03-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-04 | 1981-09-03 | 1982-03-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-04 | 1985-09-03 | 1986-03-05 | $7700.00 | Window Closed / Lapsed |