US2587508A

US2587508A - Seal hanger for floating roofs

Info

Publication number: US2587508A
Application number: US745444A
Authority: US
Inventors: Frederick D Moyer; Leonard P Zick
Original assignee: Chicago Bridge and Iron Co
Current assignee: Chicago Bridge and Iron Co
Priority date: 1947-05-02
Filing date: 1947-05-02
Publication date: 1952-02-26
Anticipated expiration: 1969-02-26

Description

' Feb. 26, 1952 F. D. MOYER EI'AL SEAL HANGER FOR FLOATING ROOFS Filed May 2, 1947 J lea/m j 550% wmwfiwa/ Patented Feb. 26, 1952 PATENT OFFICE 2,587,508 sEALnANeERroR FLOATING R'OOF'S' FrederiekfD. Moyerand Leonard 'P. Zic'k, Ghicago, 111., 'ass'ignors' to Chicago Bridge 8;, Iron -Gom-;

pany, a corporation mf Illinois Application May .2, 1947, 'SerialNo.745,444

"Ia-clai s. (01. 220-26.)

This invention relates to a liquid storage tank,

and more '-part'icularly to a new improved shoe supporting means for use in coin notion with a floaitins'lroof in a liquid storage tank.

.l'siqiiid' storage tanks employing" a floating roof as the top closure for the liquid stored therein aref'being widely adapted as ;the imost 'efiic'i'ent method or storing'volatil'e liquids, such as petroleumwprodllcts. such floati'rfgroof tanks usually provide for afiexibl'e SeaI'ftQ'seaI'thespace between the roof; and a. plurality of s 'es which slide aljon "the. inners'ide walls of ,Numerd porting the shoes against, side; walls otlthe tank,

, e tank. methods have been devised for submany of which have been extremelycomplicated in nature;

We have invented and are her in; disclosing and claiming a shoe hanger of simple design which has many advantages that will be hereinafter pointed out; Thi's'inventionis an improvem'ent; upon the co-pending application of Frederick; D. Mover filed February 1 947., as Serial No; 726,179, now Patent No. 2.554397, May 29,1951.

The invention will be described in the embodi- "Yment disclosed in' the accompanying drawing which islafvertical section through a liquid storage tank; showingjportions "of: the side walls. the floating roof, and the liquid stored in the tank.

ing 'rooi. ;has a top' 14, a side 15" and; a bottom [6. Adi-annular seal H of flexible material seals the .spacfefia between the side 15 of" the tank and a plurality of shoes 19 which slidably contact the; side, wall of the tank. 1

A Ingest: is welded to the; upper portion ofthe "side 'ISf'and has a hole 251; provided therein in which afx'pin or' shaft 22 is journale'd, the shaft being attached to the upper end of 'alever 23 to 'provideja pivotal connection of the lever to the "upper portion of the roof. The lever 23 has a downwardly extending portion, '24, an angle 25 and an mwardly extending ortion 2 6; A weight "21' is provided on the inwardly extending portion to exert a downward force upon the lever,

the position of the weight may be changed by sliding it along the portion 26' and' clamping it in any desired: position by means of the clamp jz la. Pivotally connected at 28 to the upperiportion of the shoe is a shoe supporting member 29, The other end of the shoesupporting momear is: connected to the lower portion of theside 15 by means of a pin and slot arrangement. As shown in the drawing, a bracket 30 is attached to the lower portion of the roof having a vertical slot 3|, the sides of the slot being engaged by a pin 32 attached to the lower end of the member 29'. The shoe supporting member is pivotally connected to the lever 23 at 33', as shown.

In the preferred embodiment shown; the points of connection of the member 29 to the shoe and of the lever 23 to the roof lie in the same horizontal plane and the distance along the member from the point 2 8 to the point 33 of connection to the lever equalsthe distance along the lever from that point (33) to i'ts point of connection to the roof at 22'. Also, the point 33 lies midway between the ends of the member 29.

The weight of the shoe is carried by the shoe supporting member 29 and transmitted from that member to the lever by means of the connection33. It will be noted that the angle 25 is normally spaced fromthe shoe I9 and hence does not rub against the shoe. The pin and

slot arrangement

31 and 32 permits vertical movement of the lower-end of the shoe support,- ing member 29 with respect to the roof while preventing horizontal movement thereof. Practically no vertical movement of-the shoe occurs with horizontal movement of the roof, and the forces set up by horizontal movement of the roof tend to return the roof to center. This latter feature can perhaps be best described by expressing the'vario-us forces in terms of formulae. For this purpose-let (W) equal the downward. :force exerted by the weight 2 1'; J

(w)- equal' the downward force exerted by the shoe;

(H) equal the horizontal distance from the weight 2'! to the pin- 32;

(h) equal the horizontal distance from the pin 32 to the side wall H of the tank;

(V) equal the vertical distance between-the point of connection of the lever to the roof' at "22 and the point of contact of the pin 32 with the edges of the'slot 31.

The equation of moments "(R0 about the point 33 of all theforces on the lever 23 is:

- the :force varies tance between portion, 26.

R1 is the horizontal force applied at the point 22, outward on the lever 23 and inward on the roof; R2 is the horizontal force applied at the point 32, inward on the shoe supporting member 29 and outward on the roof; and R3 is the hori zontal force applied at the point 28, inward'on the shoe supporting member 29 and outward on the shoe. 7

Then the equation of equilibrium of horizontal forces on the hanger system is:

WHwh 2WHwh whence As W is constant and both V and H increasewith decreasing h (but H increases faster than V), the roof is maintained centered in the tank.

It can be seen from the foregoing that our hanger system has certain inherent advantages.

There. is practically no vertical movement of the shoe with horizontal movement of the roof.

force pushing the shoe against the shell is con-u The stant regardless of the weight of the shoe, and

directly with the horizontal disthe weight 21 and the point of connection of the member 29 to the lower portion of the roof, that is, the pin 32. Both the outward push on the shoe and the centering force may be regulated directly by changing the posi .tion of the weight 21 on the inwardly extending.

The outward push on the shoe acts" only at the top of the shoe, that is, about the point of connection 28, but the lower portion of the shoe is not permitted to leave the side walls a distance greater than the distance of clearance between the angle 25 and the shoe, which is gen- -erally.aloout to inch. The angle 25 does -not rub on the shoe in normal operation of the roof, and any rubbing which takes place due to inward displacement of the lower portion of the shoe occurs in the liquid.

While we have shown and described our invention in its preferred embodiment, it is to be understood that it is capable of many modifica tions. Changes, therefore, in the construction and arrangement may be made without depart "ing from the spirit and scope of the invention as disclosed in the appended claims.

.We claim:

1. In a liquid storage tank having a. floating .roof and one or more shoes adapted to slidably contact the inner side walls of the tank, means .for supporting the shoes against the side walls inprevented.

supporting member being plvotally connected intermediate its ends to the downwardly extending portion of the lever and being supported thereby. 2. Apparatus of the character described in claim 1 in which said angle is normally maintained in a position spaced from the shoe.

3. Apparatus of the character described in claim 1 in which the connection of the other end of the shoe supporting member to the roof includes a bracket attached to the roof having a vertical slot therein, and a pin attached to the other end of said shoe supporting member slidably engaging the sides of the slot.

4. In a liquid storage tank having a floating roof and one or more shoes adapted to slidably contact the inner side walls of the tank, means for supporting the shoes against the side walls including a lever swingably attached to the upper portion of the roof, said lever having an angular portion immersed in the liquid, a portion extending downwardly from the point of attachment of the roof to the angular portion and a portion extending inwardly from said angle, means 'for exerting a downward force on said inwardly extending portion, and a shoe supporting member having one end attached to the upper-portion of the shoe and having the other endconnected to the lower portion of the roof, said connection to the lower. portion of the roof permitting vertical movement and substantiallypreventing, horizontal movement of said other "end with respect to the roof, and said shoe supporting member being pivotally connected intermediate its ends to the downwardly extending portion of thelever'.

5. Apparatus of the character described in claim 4 in which the point of connection of the lever to the roof and the point of connection of the shoe supporting member to the shoe lie in substantially the .same horizontal plane whereby vertical movement of the shoe with horizontal movement of the roof is prevented. ,7

6. Apparatus of the character described in claim 4 in which the point of connection of the lever to the roof and the point of attachment of the shoe supporting member to the shoe lie in substantially the same horizontal plane, and the distance from the point of attachment of the shoe supporting member to the shoe to its point of pivotal connection to the lever is substantially equal to the distance from said point of pivotal connection to the point of connection of the lever to the roof, whereby vertical movement of the shoe with horizontal movement of the roof is 7. In a liquid storage tank having a floating roof and one or more shoes adapted. to slidably contact the inner side walls of the tank, means for supporting the shoes against the side walls includin a lever swingably attached to the upper portion of the roof, said lever having an angular portion, a portion extending downwardly from the point of attachment of .the roof to the'angular portion .and -a portion extending inwardly from said angle, a weight connectable to said inwardly extending portion at a plurality of posi tions for exerting a downward force thereon, a shoe supporting'member having one end attached to the upperportion of the shoe and havingthe other end connected to the lower portion of the roof, said connection to the lower portion of the roof permitting vertical movement and substant1ally preventing horizontal movement of said supporting member exerting an outward force against said shoe to hold the same against the side walls and an inward force against the roof tending to move the roof away from the side walls, said inward force varying inversely as the distance between the roof and the side walls whereby to center the roof in the tank, and said weight being connectable to saidinwardly extending portion at a plurality of positions whereby to vary said forces exerted by said shoe supporting member.

8. Apparatus of the character described in claim 7 in which the point of connection of the lever to the roof and the point of attachment of the shoe supporting member to the shoe lie in substantially the same horizontal plane, and the distance along said shoe supporting member from the point of attachment to the shoe to its point of pivotal connection to the lever is substantially equal to the distance along said downwardly extending portion fromsaid point of pivotal connection to the point of connection of the downwardly extending portion to the roof.

9. Apparatus of the character described in claim 8 in which said shoe supporting member is pivotally connected to the downwardly extending portion at a point substantially midway between its said ends.

10. In a liquid storage tank having a floating roof and one or more shoes adapted slidably to contact the inner side walls of the tank, means for supporting the shoes against the side walls including a pair of levers, one pivotally connected to the shoe and slidably connected to the roof and the other pivotally connected to the central portion of the first lever and pivotally connected to the roof, the pivotal connection of one lever to the roof and of the other lever to the shoe being in substantially the same horizontal plane and means to provide a force tending to separate the shoe and the roof which is substantially inversely proportional to the distance between the shoe and the roof whereby no vertical force acting in the plane of the shoe affects the pressure between the shoe and the side walls.

11. In a liquid storage tank having a floating roof and one or more shoes adapted slidably to contact the inner side walls of the tank, means for supporting the shoes against the side walls including a pair of levers, one pivotally connected to the shoe and slidably connected to the roof to permit relative vertical movement and the other pivotally connected to the central portion of the first lever and pivotally connected to the roof, the pivotal connection of one lever to the roof and of the other lever to the shoe being in substantially the same horizontal plane, both connections to the roof being substantially vertically spaced from each other and means to provide a force tending to separate the shoe and the roof which is substantially inversely proportional to the distance between the shoe and the roof whereby no vertical force acting in the plane of the shoe affects the pressure between the shoe and the side walls.

12. In a liquid storage tank having a floating roof and one or more shoes adapted slidably to contact the inner side walls of the tank, means for supporting the shoes against the side walls including a pair of levers, one pivotally connected to the shoe and slidably connected to the roof and the other pivotally connected to the central portion of the first lever and pivotally connected to the roof, the pivotal connection of one lever to the roof and of the other lever to the shoe being in substantially the same horizontal plane whereby no vertical force acting in the plane of the shoe affects the pressure between the shoe and the side walls.

FREDERICK D. MOYER. LEONARD P. ZICK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,660,021 Wiggins Feb. 21, 1928 1,673,984 Kuhl June 19, 1928 2,145,812 Einbeck Jan. 31, 1939 2,388,163 Laird Oct. 30, 1945 2,471,404 Boberg May 31, 1949 FOREIGN PATENTS Number Country Date 549,419 Germany Apr. 14, 1932