US3841676A

US3841676A - Manhole closing arrangement

Info

Publication number: US3841676A
Application number: US00302394A
Authority: US
Inventors: N Hover
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-10-31
Filing date: 1972-10-31
Publication date: 1974-10-15
Anticipated expiration: 1991-10-15

Abstract

A closing arrangment for manholes and similar hatches defined by a coaming, includes a yoke which extends across the coaming, a cover being suspended from the yoke and being adapted to be pressed by the yoke downwardly against the coaming. One end of the yoke is detachably connected with the coaming by means of a horizontally pivotable catch, while the other end of the yoke is connected to the coaming by means of a pair of interengaged sliding elements respectively connected to the coaming and to the yoke so as to permit a vertically and angularly relative movement of these elements for a raising, lowering and angular movement of the cover.

Description

Unite States Patent. {1 1 Hover [451 Oct. 15,1974

[ MANHOLE CLOSING ARRANGEMENT [76] Inventor: Nils Th. Hover, Bygdoy Alle 98, Oslo, Norway [22] Filed: Oct. 31, 1972 [21] Appl. No.: 302,394

[51] Int. Cl. E05c 15/00 [58] Field of Search 114/203; 292/256.5

[56] References Cited UNITED STATES PATENTS 938,593 11/1909 Laubeuf .f. 114/203 2,224,292 12/1940 Dwyer 292/2565 2,816,683 12/1957 Miers et a1 292/2565 Primary Examiner-Geo. V. Larkin [57] ABSTRACT A closing arrangment for manholes and similar hatches defined by a coaming, includes a yoke which extends across the coaming, a cover being suspended from the yoke and being adapted to be pressed by the yoke downwardly against the coaming. One end of the yoke is detachably connected with the coaming by means of a horizontally pivotable catch, while the,

other end of the yoke is connected to the coaming by means of a pair of interengaged sliding elements respectively connected to the coaming and tothe yoke so as to permit a vertically and angularly relative movement of these elements for a raising, lowering and angular movement of the cover.

6 Claims, 7 Drawing Figures PAIENTEDOBI I 51974 sum 1 or 2 MANHOLE CLOSING ARRANGEMENT The present invention relates to an arrangement for the closing of manholes or similar hatches which are defined by a coaming which may form a sealing surface against a cover. Such openings, which are required for the purpose of inspection and/or maintenance in tanks or other closed spaces adapted for storing and/or transport of liquids or gases, may be of highly different circumferential shape, and the covers used for the closing may have a plane or other surface, according to the stresses to which the cover is to be subjected.

The closing systems of such openings must satisfy a number of requirements. The sealing must be good, closing and opening must be performed in a simple manner with the least possible consumption of energy, the system must not comprise loose parts which may easily go astray, and the cover must not in open condition form any obstacle and neither must it be unintentionally movable. A previously usual system, having a number of pin screws distributed along the circumference of the coaming, and corresponding holes in the cover edge and a corresponding number of nuts, does not satisfy nearly any of the requirements mentioned, and the same is the case with covers which are hinged on the coaming about an axis in the plane of the cover, as the sealing in such door structures can scarcely be faultless. 1

Further, a system is known in which a loose cover is pressed down against the hatch coaming by a centrally attacking screw which is engaging a yoke which is carried across the hatch and at one end hinged on the hatch coaming about a horizontal axis and at the other end engages a loop on the hatch coaming. Thus, in this system slso, the cover forms a loose unit, and the yoke required a great free height above the hatch for its pivotal movement.

The present invention relates to a closing system of the type which comprises a yoke which extends across the hatch and is adapted to press a cover against the hatch edge, but is distinguished from the previously known closing systems therein that the cover is centrally suspended in and maybe lifted, lowered and set bymeans of the yoke which is detachably connected to the hatch coaming at each end. Due to the fact that the cover is suspended in the yoke, the two members form one unit, wherein the members cannot be lost relative to each other, and the detachable connections at both ends of the yoke may be so made that one connection, as known perse,'forms a hold-down, while the other forms a mechanism which permits both movement in a direction at right angles to the plane through the cover, ie a setting or an opening movement, respectively, and a pivotal movement of the yoke with the suspended cover in a plane extending parallel to the plane through the cover.

The suspension of the cover on the yoke may suitably be so made that the yoke is provided with a projection directed towards the cover and provided with a hole which is oblong in the direction towardsthe cover and adapted to receive a pin which extends through two uprights on the top surface of the cover, to either side of 'the yoke projection, whereby yoke and cover are provided with a certain motion liberty, at the same time as the setting force is transmitted from yoke to .cover through the yoke projection which abuts against the surface of the cover, whilethe cover pin is without stress when the hatch is closed.

The connection between one end of the yoke and the coaming may conveniently be in the form of a jack device, in which one part is solidly connected to the coaming and the other part is connected to the yoke and may be moved rectilinearly relative to the stationary part, at right angles to the plane through the cover and pivot about an axis of the rectilinear movement, so that the yoke with the suspended cover may be lowered and lifted relative to the coaming and be pivoted outwardly sideways of the coaming.

Further features and advantages of the system according to the invention will appear from the following description of a preferred embodiment of the system, and from the claims.

The accompanying drawings schematically illustrate an example of how a system according to the invention may be designed.

FIG. 1 is a side view of the system with its hatch coaming, in closed condition.

FIG. 2 is a plan view of the system, in closed condition.

FIG. 2A is a sectional view,.at a slightly enlarged scale, taken along the line 2A--2A of FIG. 2.

FIG. 3 is a side view of the system in open condition.

FIGS. 34; and 3b are sectional views through alternative sealing means between cover and batch coaming.

FIG. 4 is an axial sectional view of the jack'device.

In the drawings,] is the top wall of a tank which may be adapted for storing or transport of liquids or gas, such as aboard a ship. For the purpose of inspection or for other purposes the tank is provided with a hatch which is defined by a coaming 2 and which is to be sealingly closed by means of a cover 3. The hatch and its coaming may have any circumferential shape and the cover may be of various designs. In the example shown,

it is presumed that the hatch coaming is circular and.

that the cover is plane and provided with reinforcing ribs 4. Along the circumference of the coaming 2 and the cover 3 there is provided single or double sealing means, as shown in FIGS. 30 and 3b, respectively, comprising a gasket 5 made of a material and ina shape which depend on the substanceto be held in the tank and the vapor from the same.

For the purpose of positioning and setting the cover 3 on the coaming 2, there is provided a yoke 6 extending across the hatch centrally relative to the cover 3, the yoke being provided with projections 7 which extend towards the cover 3. Each projection is provided with an oblong hole 8 for the reception of a pin 9 provided on each of a pair of uprights 10 on the cover. FIG. 2A illustrates the details of such arrangement.

At one end, to the right in F110. 1, the yoke 6 is adapted to co-operate with a pair of plates 11 which are hinged at 12 to a bracket 13 on the hatch coaming 2. In the example shown, plates 11 are provided with a pin 32 which may co-operate with a corresponding recess in the top face of the yoke 6. At this end, the yoke is also provided with a forked projection comprised of plates 14 adapted to cooperate with the bracket 13 on the hatch coaming for the guidance of the yoke 6. Plates 14 are secured toopposite sides of the yoke as in FIG. 2.

At the other end, to the left in FIG. 1, the yoke 6 is provided with cars 15 having holes 16 (shown in FIGS.

3 l and 3) for hinge connection to the movable part of a jack which is generally referenced 17. Such connection is effected by means of pins 23.

The jack 17 comprises a cylindrical member 18 which encloses a second cylindrical member 19 and may be moved axially and rotated relative to the latter. The axial movement is effected by means of a screw threaded bar 20 attached to a hand wheel 21, engaging a nut 22 which is fixedly connected to the inner cylinder 19. The screw' threads of the bar 20 and of the nut 22 conveniently are of the self-locking type, so that the connection between the bar and the nut cannot be influenced by vibrations or shocks in the plant as a whole. The yoke 6 is connected to the outer cylinder 18 through pins 23 and the inner cylinder 19 is fixedly connected to brackets 24 on the hatch coaming. At the lower end, the outer cylinder 18 is provided with a pair of diametrically positioned projections 25 adapted to co-operate with correspondingly positioned recesses 26 provided in a collar or the like 27 which is secured to the inner cylinder 19. The projections 25 and the recesses 26 are so shaped for interengagement, and for avoiding spark provoking shocks which may occur when they are entering into engagement with each other. The projections 25 and the recesses 26 form a claw coupling which can angularly lock the

cylinders

18 and 19 relative to each other, at the same time as the cylinders are freely rotatable relative to each other upon an initial axial movement of the outer cylinder 18. Obviously, the jack 17 is provided with antifriction discs and a shoulder 28, and the two

spaces

29 and 30, respectively, may be filled with a suitable oil, grease or the like, for the purpose of assuring lasting sealing and friction conditions.

Below ears 15, the yoke is provided with an arm 31 extending downwardly and adapted to contact the outer surface of the movable member 18 of the jack 17.

The system of the invention may be used in the following manner.

Under the conditions illustrated in the FIGS. 1, 2 and 3a, 3b, with the cover 3 in place upon the coaming 2 and the yoke 6 in place, the pin 32 of plates 11 is in engagement 'with'its corresponding recess in the yoke 6. Projections 7 on the yoke 6 are in contact with the top surface of the cover 3, with the pins 9 on the cover in free engagement with the hole 8 in the projection 7. The other end of the yoke 6 is in engagement with the pins 23 on the outer cylinder 18 of the jack 17.

Through rotation of the hand wheel 21, the cylinder 18 and thereby this end of the yoke 6 is then moved downwardly relative to the second cylinder 19, i.e. relative to the coaming 2. Hereby, the recess at the right hand end of the yoke 6 is applied against the pin 32 of plates 11, projections 7 press against the top surface of the cover 3, the gaskets are sealed and the

claw coupling

25, 26 is closed. The more the hand wheel 21 is rotated, the more the cover 3 is pressed against the circumference of the coaming 2, with a force applied at the circumference which depends upon the lever arm present, i.e. the distance between the pins 23, projections 7 and plates 11, so that a sealing pressure in the gaskets 5 is provided which is twice the setting force of the jack l7.

When the hatch is to be opened, the hand wheel 21 is released and the jack member 18 with suspended yoke 6 is lifted, the projection 31 on the yoke 6 thereby contacting the cylinder 18, so that the yoke 6 brings along the cover 3 through engagement between pins 9 and the lower end of the holes 8 in projections 7. The sealing effect of the gaskets 5 is released. Eventually, plates 11 may be turned outwardly about pivot 12 and the

claw coupling

25, 26 is disengaged,'so that the cylinder 18 may be rotated relative to the cylinder 19 and the cover 3, thereby swung outwardly and, through a renewed lowering of the jack 17, adopt the position shown in FIG. 3, in which the parts are again locked relative to each other by the

claw coupling

25, 26 without any danger of unintentional swinging movement of the cover about the longitudinal axis of the jack 17.

When the hatch is again to be closed, the member 18 of the jack 17, with suspended cover 3, is lifted until the

claw coupling

25, 26 is disengaged. The cover is the swung about the axis of the jack, which is again lowered, and the cover assumes a correct position on the coaming 2 guided by the fork l4 and the bracket 13, so that plates 11 maybe swung upwardly over the end of the yoke, for engagement between the loop pin 32 and the recess in the top face of the yoke. At the same time, the

claw coupling

25, 26 begins to close, and the cover is ready for the setting movement effected by rotation of the hand wheel 21, the cover pins 9 being freely received in the oblong holes 8 without transferring any force between yoke and cover. Thus, the

claw coupling

25, 26 has a triple purpose. When the cover 3 is in an oubswung position, the coupling locks the cover against unintentional swinging movement. When the cover 3 is lifted, with disengaged coupling, the projections 25 slide on the ridges between the recesses 26 during swinging movement of the cover, thereby maintaining the cover at a predetermined height until the projections 25 meet their recesses 26. The cover is then lowered and is accurately guided downwardly against the gaskets 5, with the fork l4 guided by the bracket 13.

I claim:

1. A closing arrangement for manholes and similar hatches defined by a coaming, comprising a yoke extending across said coaming, a cover suspended from said yoke and being adapted to be pressed by said yoke downwardly against said coaming, one end of said yoke being detachably connected with said coaming by means of a horizontally pivotable catch, the other end of said yoke being connected to said coaming by means of a pair of interengaged sliding elements respectively connected to said coaming and to said yoke, said elements being vertically and angularly movable relative to one another thereby permitting a raising, lowering and angular movement of said yoke and said cover.

2. The arrangement according to claim 1 wherein said cover is suspended from said yoke by means of at least one projection on said yoke extending toward said cover, said projection having a vertically enlongated opening therein, and at least one upstanding ear member on said cover having a pin thereon extending into said opening.

3. The arrangement according to claim 1 wherein a guide plate is secured to said one end of said yoke at each side thereof, a bracket provided on said coaming, said guide plates engaging with opposite sides of said bracket, and said catch being horizontally pivotable on said bracket and being releasably engageable with said one end of said yoke.

said locking means are in the form of a claw clutch.

6. The arrangement according to claim 4 wherein a vertically extending bracket plate is provided at said other end of said yoke to facilitate mounting of said yoke to said one element.

Claims

4. The arrangement according to claim 1 wherein said elements comprises hollow tubes in telescoping relationship, jack means for vertically moving one of said elements relative to the other, and cooperating locking means on each of said elements for locking said elements into a predetermined angular position.

5. The arrangement according to claim 4 wherein said locking means are in the form of a claw clutch.