US3365175A - Travel limiting device for the travelling block of hoisting installations provided with pneumatic controls - Google Patents

Description

Jan. 23, 1968 D. POMPILIU ETAL 3,365,175

TRAVEL LIMITING DEVICE FOR THE TRAVELLING BLOCK OF HOISTING INSTALLATIONS PROVIDED WITH PNEUMATIC CONTROLS Filed March 24, 1965 2 Sheets-Sheet 1 I In ven tors.-

ram -.1. nummescu TURICU ocmvmm TRmAN fh ir Afforney 3,365175 CK OF Jan. 23, 1968 D. POMPILIU ETAL TRAVEL LIMITING DEVICE FOR THE TRAVELLING BLO HOISTING INSTALLATIONS PROVID ED WITH I PNEUMATIC CONTROLS Filed March 24, 1965 2 Sheets-Sheet 2 In ven tors.- Porhpil-iu-DUMITRESCU TURICU ocrqwlm TRmAN 6,; Q {hei Affomey United States Patent 3,365,175 TRAVEL LIMITING DEVICE FOR THE TRAVEL- LING BLOCK OF HOISTING INSTALLATIONS PROVIDED WITH PNEUMATIC CONTROLS Dumitrescu Pompiliu, B-dul Republicii 55, and Octavian Traian Turicu, Str. Bach Bloc 8/5, both of Bucharest, Rumania Filed Mar. 24, 1965, Ser. No. 442,465 Claims priority, application Rumania, Mar. 31, 1964, 47,741 4 Claims. (Cl. 254-173) This invention relates to a limiting device for the travel of the travelling block used in conjunction with drilling rigs, hoists and similar installations.

A travel limiting device for the travelling block of draw works is already known in the art. In this known device the stopping operation is effectuated by means of an air valve (mounted on the derrick floor) and actuated directly by the travelling block, by means of a cable line.

This known device presents the disadvantage of having the control valve mounted on the derrick floor and close to the rotary table of the derrick, which causes it to be exposed to bad weather and to the corrosive action of the water and drilling fluid. Since this device is idle most of the time, the valve can easily become stuck. Thus, conditions can occur when the valve counterweight is not great enough to actuate a stuck valve of the device.

The connecting cable line being quite thin, it has been found to be prone to be carried away by the drilling line, which causes it to enter between the travelling block sheaves and wire rope, thus damaging the device.

The adjustment of the limit height, for the travelling block travel, is difiicult, because a changing of the attachment point of the cable line to the derrick braces is required, this operation can only be carried out at a i great height and with great difiiculties.

There is also known another travelling block travel limiting device, which can be mounted in the drilling rig derricks. This known device has a safety valve attached to the draw works, and is actuated-at a preselected moment-by the layers of drilling line spooled onto the hoisting drum.

The safety valve of this known device stops the travelling lock at a safe level in the derrick, by actuating the hoisting drum brake and simultaneously therewith disengaging the power groups from the draw works.

This known device presents the shortcoming that in case of an irregular spooling of the drilling line which can happen quite frequently, the layers of drilling line can get interpenetrated (wraps belonging to the upper layer can get inbetween the lower layer wraps) and, consequently, the device can stop the travelling block too early, or too late, the latter case being quite dangerous.

It is a general object of this invention to eliminate the above mentioned disadvantages by having the entire travelling block travel limiting device mounted in a completely enclosed space inside the draw works, and having the device actuated directly by the draw works hoisting drum.

This invention relates to a travel limiting device for travelling blocks belonging to hoisting installations and comprises a threaded rod with a nut mounted thereon which is driven by the hoisting drum shaft; a pneumatic stop valve which actuates a control relay, by means of which, and depending on the nut position on the threaded rod, the air passage to the hoisting drum clutch is opened or closed, and concomitantly therewith the hoisting drum is accordingly started or stopped. This hoisting drum stoppage is effectuated by means of the pneumatic drum brake, which is activated by means of a switch valve and a brake release valve which brings out of action the hoisting drum and respectively stops automatically the travel- "ice ling block at a safe height established by an initial adjustment. This adjustment consists of conveniently rotating the aforementioned threaded rod until the nut, which is moving on it, trips the pneumatic stop valve at the desired moment.

Two illustrative embodiments of a machine constructed in accordance with the invention, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments, when read in connection with the accompanying drawing, in which:

FIG. 1 is a schematic illustration of a travelling block travel limiting device according to this invention, attached to a. drilling rig, without an automatic hoisting drum stop FIG. 2 is a schematic illustration of the same device, as illustrated in FIG. 1, but with an automatic hoisting drum stop.

Referring now specifically to the drawing, two examples of the device of this invention are described.

Example I The device, according to the invention and illustrated in FIG. 1 comprises a driving wheel 1, coaxially attached to the hoisting drum shaft 2, which in turn drives a threaded rod 5 by means of a chain 3, a sprocket wheel 4 and a transmission arrangement 6 (bevel gear, helical gear, worm gear, etc., transmission).

The sprocket wheel 4 is secured to its supporting shaft by means of a cone, which is used for adjusting the device in accordance with the number of travelling block lines, respectively in accordance with the maximum allowable height. The structure of the adjusting cone is stand ard and, consequently, well known in the art and has not been illustrated in detail.

The installation includes also a nut 7 which can be shifted, without rotating it, along the threaded rod 5. A pneumatic stop valve A, which is actuated by a pivotable control lever 8 having a roller at its free end, and a main relay B, both of which are connected together by means of the air lines 9 and are also connected to the main compressed air system 10 for the device. The pneumatic stop valve A comprises a housing 11 having a vent opening at one end thereof, a valve member 12 axially movably mounted therein, a spring 13, urging the valve member 12 into a closed position, and a valve member 14 with a control rod, which cooperates with the lever 8.

The housing 11 is provided with a compressed air supply inlet orifice 15 and an outlet orifice 16, which allows the air to pass towards the main relay B.

The main relay B comprises a housing 17 composed of three compartments and a lid 18. A rubber diaphragm 19 is mounted between the lid 18 and the lower ends of the outer walls of the housing 17. The diaphragm 19 is urged upwardly by a coil spring 20.

Inside the housing 17 there is mounted a valve member 22 which cooperates with the valve seat member 21 and the valve seat 21a. A valve closing spring 23 acts on the valve member 22.

The housing 17 is provided with an orifice 24 through which the air is entering from the stop valve A. An orifice 25 in the wall of housing 17 serves as an inlet for the air supply, and an orifice 26 in the wall of housing 17 provides an outlet for the air to pass towards the clutch (not shown). An orifice 27 in the housing 17 permits a bleeding off of the air from the clutch. The compressed air passing through opening 27 is released into the atmosphere.

The device of this invention operates as follows:

In the first place the device has to be adjusted and for this purpose, the travelling block is brought to the upper limit position, the sprocket wheel 4 is loosened and the shaft is rotated by means of a wrench (not shown) 3 until the nut 7-which is shifted along the threaded rod 5 by means of the drive 6strikes the control lever 8, thereby tripping the device. in this position, the sprocket wheel 4 is again fastened onto its corresponding supporting shaft by means of its locking cone and lock nut.

After this adjustment has been made as long as the drilling rig is working without the travelling block exceeding the safe height, the nut 7 shifts along the rod 5 in one direction or another without striking the control lever 8; the compressed air from the main line 11 can not pass towards the relay B, through the orifice 24, because the valve member 12 from the stop valve A is in its closed position, but it can pass through the relay B orifice 25, and because the valve member 22 is in its open position, the air can pass freely through the orifice 26 towards the reverser or hoisting drum clutch (not shown) and, consequently, the drum is placed in its working position.

When the nut 7, belonging to the travel limiting device, strikes the lever 8, however, the valve member 14 from the stop valve A is pushed toward the interior of the housing 11, thus closing the air release to the atmosphere, and opening the valve member 12. Now the compressed air can pass from the orifice 15 towards the outlet orifice 16, and from there through the orifice 24 to the relay B.

Thus the left plate 12a of valve member 12 closes the passage for the compressed air towards the space in communication with the orifice 16. It should also be noted that during the operation of the device the orifice 15 never comes directly into communication with the atmosphere, which would result in unnecessary losses of compressed air.

While the stop valve A is in the aforedescribed position the orifice 16 communicates with the atmosphere via the space between the right hand plate 12b of the valve member 12 and through the central passage 14a of the valve member 14 and through the vent opening 11a at the right end wall of the valve housing 11.

When the valve member 14 is pushed inwards, it meets first the right hand plate 12b of valve member 12 thereby closing the communication between the orifice 16 and the atmosphere. Continuing its inward stroke, valve member 14 pushes valve member 12 toward the left thereby lifting the left hand plate 12a from its valve seat and placing orifice 15 in communication with orifice 16.

On the other hand when the valve member 14 is again pushed outwardly by the springs 12c and 13, the valve member 12 follows, due to the action of the spring 13, thereby cutting off the connection between the orifices 15 and 16 by repositioning the plate 12a on its valve seat. The valve member 14,, which continues its outward movement, can no longer be followed by the valve member 12 and, consequently, the right hand plate 12b lifts off the opening for the passage 14a thereby establishing a communication between the orifice 16 and the atmosphere. The main relay B works as follows when the stop valve A assumes the aforedescribed two positions:

(a) When the orifice 24 is placed in communication with the atmosphere by the stop valve A (the component parts of the relay B and stop valve A are in the positions illustrated in FIG. 1) the coil spring 20 acts on the valve seat 21 member via the membrane 19 and urges it to the upper limit of its stroke. The lower plate 22a of the valve member 22 comes to rest on the valve seat member 21, whereas the upper plate 22b is raised from its valve seat 21a. When the component parts of the relay B are in the aforcdescribed position the orifice 26 places the compressed air via the orifice 25 in communication with the pneumatic clutch of the drawworks (not illustrated) and closes at the same time the communications of the orifice 26 with the atmosphere.

(b) When the orifice 24 is placed in communication with the source of compressed air via the orifices 15 and 16 the pressure formed in the lower chamber of the relay B causes the membrane 19 to deflect downwardly thereby entraining the valve seat member 21 to which it is connected. The valve member 22, due to the action of the spring 23, follows the valve seat member 21 until its upper plate 22b comes to rest on the valve seat 21a. This causes a closing of the flow path from orifice 25 to orifice 26. Since the valve seat member 21 has a longer stroke than the valve member 22, the valve seat member 21 continues its downward stroke, thereby disengaging itself from the lower plate 22a, and by means of the channels disposed in its body places the orifice 26 in communication with the atmosphere. In this manner the compressed air in the clutch is dissipated and the clutch disengages itself.

When the pressure at the orifice 24 is discontinued (when the orifice 16 is in communication with the atmosphere i.e. the position illustrated in FIG. 1), the relay B returns to the position illustrated in FIG. 1.

It should be noted that both the relay B and the stop valve A operate similarly in principle i.e. first the flow path between the orifice 25 and the atmosphere is closed and only afterwards the flow path between the source of compressed air and the orifice 26 is opened. This is due to the similar operation of the valve member pairs 12, 14 and 21, 22.

Consequently, the valve member 22 closes the entrance of the compressed air towards the clutches (not shown); the air from the drum and reverser clutches is bled off into the atmosphere through the central orifice of the valve seat member 21 and through the bleeder orifice 27, thereby uncouples the hoisting drum from its drive. Simultaneously with the drum uncoupling the travelling block is stopped. When through the relay B, the entire drilling rig is fed with compressed air, the above mentioned safety device uncouples all the rig clutches including those provided for the engines, and in this case it insures the complete protection of the rig even in the case when due to diverse reasons, the drawworks and reverser clutches got stuck.

Example II The device according to this invention illustrated in FIG. 2 comprises a driving wheel 28 attached to a hoisting drum shaft 29, which in its turn is driving by means of a chain 30, a sprocket wheel 31, which is fastened onto its supporting shaft by means of a cone which is used for the adjustment of the device. The adjustment is made in accordance with the number of cable lines on the travelling block, respectively in accordance with the maximum height allowed for the travelling block travel. The structure of the adjusting cone is standard and consequently well known in the art and has not been illustrated in detail.

Through a gear 32 (which can be cylindrical, bevel, helical or worm gear) there is driven the gear wheel 33 which is axially secured to the threaded rod 34.

The device includes also a nut 35, which can be longi tudinally shifted-without rotatingalong a threaded rod 34. A pneumatic stop valve C is actuated in its turn by a control lever 36 having a roller at its free end. The device further includes main relay D, a releasing valve E, a switch valve F, a hoisting drum control valve G and a control valve H for the hoisting drum pneumatic brake, all of which form part of the device and are operatively connected to each other in an arrangement that will be set forth below.

The pneumatic stop valve C comprises a valve body 37, a control and unload valve member 38 axially movably mounted in the valve body 37. A spring 39 is mounted inside a cavity of the valve body 37.

A stop valve member 40 actuated by a valve spring 41 is mounted inside a valve seat member 42. A threaded guide member cover 43 is axially mounted in the lower end of the valve body 37 and seals a compartment situated therein and serves also to guide the valve member 40. The valve body 37 is provided with an inlet orifice 44 for compressed air feeding, and an orifice 45 for letting air pass towards the main relay D.

The main relay D comprises a valve housing 46, a valve member 47 axially movably mounted therein, a double valve seat 48 mounted inside the housing 46. A coil spring 49 urges the valve member 47 downwardly into a closed position. A threaded lid 50 having a central bore is threadably mounted into the upper end of the housing 46.

The housing is provided with an orifice 51 for air inlet from the stop valve C; an orifice 52 for compressed air feeding from the main compressed air feeder line 67, an orifice 53 for permitting air to pass towards the hoisting drum clutch and the aforementioned orifice 54 for air bleed-off into the atmosphere.

The release valve E comprises a valve cylinder 55, in which there is axially movably mounted a distribution piston 56. A button lid 57 is secured to the lower end of the piston 56. A reset spring 58 urges the button lid 57 downwardly.

The valve cylinder is provided with an orifice 59 which acts as an air inlet for air coming from the switch valve F; an orifice 60 which acts as an air outlet for air passing towards a pneumatic brake for the hoisting drum; and an orifice 61 for bleeding ofi the air into the atmosphere.

The switch valve F is composed of a body 62 and a switch piston 63 axially movably mounted therein. The body 62 is provided with the orifices 64, 65 and 66, the functions of which will be set forth below.

The stop valve C, the main relay D, the release valve E, the switch valve F and the control valves G and H are connected together by a series of lines through which the compressed air is effectuated from the main pipe line 67.

The device operates as follows:

In the first place, the adjustment of the device is required to be carried out, and for this purpose, the travelling block is brought to its upper limit position; the sprocket wheel 31 is loosened and the shaft 34 is turned by means of a wrench (not shown), until the nut 35 strikes the control lever 36, thereby tripping the device.

In this position, the sprocket wheel 31 is fastened onto its corresponding shaft, by means of the locking cone and lock nut.

After this adjustment has been made as long as the drilling rig is working without the travelling block exceeding the safe height, the nut 35 is shifting, in one direction or another, along the threaded rod 34 without striking the control lever 36; while the control lever 36 is not tripped the compressed air from the main line 67 can not pass towards the relay D through the orifice 51, because the valve member 40 of the stop valve C remains in its closed position; however, the compressed air can pass during this time through the orifice 52 and relay D, and from there through the double valve seat 48 and orifice 53, the air then being further directed towards the hoisting drum clutch, through the intermediary control valve G, thus placing the drum in its working position.

When the nut 35 strikes the lever 36, the valve member 38 of the stop valve is pushed towards the interior by the lever 36, thus shutting off the air release into the atmosphere of air passing along valve member 38. Concomitantly therewith the valve member 40 is opened and the compressed air coming from the orifice 44 now passes through the orifices 45 and 51 towards the relay D. Consequently, the valve member 47 shuts off the air entering from the main line 67 (through orifice 52) by moving upward the valve member 47 and seating it on the lower seat of the double valve seat 48.

Simultaneously therewith, the drum 29 is uncoupled because the air from the clutch is bled off into the atmosphere via the valve G, the orifice 53, the upper 6 seat of the double valve seat 48 and finally through the orifice 54.

Simultaneously with the hoisting drum uncoupling, there takes place the drum automatic braking-respectively travelling block stopping, as follows:

The air which passes towards the orifice 51, enters the switch valve F through orifice 64 and pushes the rubber piston 63 towards orifice 65 which is thereby closed. The air thereafter passes through orifice 59 towards the unloading valve E, and from there through orifice 60 towards the pneumatic brake servomotor K, which causes by means of a lever arrangement to actuate a brake for braking the drum 29.

The restarting of the hoisting drum 29 requires the following operations to be performed:

The unloading valve E button is pushed, thereby blocking orifice 59, and the air from the hoisting drum pneumatic brake can then be bled off into the atmosphere, passing first through orifice 60, then around the distribution piston 56 annular space and finally through the atmosphere through orifice 61.

Afterwards the drum can be unwound (the drum brake being manually controlled) until the contact between the nut 35 and control lever 36 is broken. In this position, the stop valve C, by the action of spring 41, closes the air entrance towards the main relay D (the valve member 40 is seated on its seat 42) opening at the same time to the atmosphere the compressed air in the air line 68, through the orifice 45 and the valve member 38 central exhaust port.

Consequently, the valve member 47 of the main relay D returns to its initial position due to the action of the coil spring 49, and the hoisting drum clutch can be fed again with the compressed air from the main line, which, of course, passes again through the control valve G.

From the moment the pipe line 68 is put in communication with the atmosphere, the manual pressure on the button 57 is interrupted and the pneumatic pressure on the brake for the hoist drum is, consequently, also interrupted and, consequently, the pneumatic braking of the hoisting drum by means of the control valve E becomes normal (when the valve H is opened, the compressed air pushes the piston 63 towards the orifice 64, closing it and the compressed air now passes through the orifice 59, through the piston 56 annular space and orifice 60, whereby it brakes the drum at a rate preselected by the operator) The device of this invention presents the following advantages:

It has a greater sensitivity and, consequently, it instantaneously uncouples and brakes the hoisting drum, thereby automatically stopping the travelling block at a predetermined safe level;

It renders greater safety during operation of the hoisting installation;

It is easily adjusted, due to the fact that it is connected to the draw works.

Although this invention has been illustrated and described with reference to two preferred embodiments thereof, it is to be understood that it is in no way limited to the details of such embodiments but is capable of numerous modifications within the scope of the appended claims.

What we claim is:

1. In a hoisting installation of the character described having a pneumatic source of power, a travel limiting mechanism including a drum for spooling a cable thereon which is operatively mounted in said installation; a pneumatically actuated clutch operatively connected to said drum; stop valve means having an inlet and outlet; a first valve member reciprocally mounted in said stop valve means and responsive to rotation of said drum; pneumatic relay Valve means having a first inlet, a first outlet, a second inlet, and a second outlet; the first inlet of said pneumatic relay valve means being in communication with the outlet of said stop valve means, the inlet of said stop valve means being in communication with said pneumatic source of power and the first outlet of said pneumatic relay valve means being in communication with said pneumatically actuated clutch and with said second inlet; said second inlet being in communication with said pneumatic source of power; a second valve member reciprocally mounted in said relay valve means; said first and second valve members being adapted to respectively cooperate with the inlets and outlets of said stop valve means and pneumatic relay valve means 50 that when said first valve member is acted on by said drum it moves in said stop valve means from a position wherein the inlet and outlet thereof are not in communication with each other to a position wherein the inlet and outlet thereof are in communication with each other, thereby placing the first inlet of said relay valve means in communication with said pneumatic source of power, via the inlet and outlet of said stop valve means, said pneumatic source of power thereby acting on said second valve member and operatively moving the latter from a position in which the first outlet thereof is in communication with said pneumatic source of power via the second inlet thereof to a position wherein said first outlet is in communication with said second outlet.

2. In a hoisting installation of the character described, having a pneumatic source of power, a travel limiting mechanism as set forth in claim 1, including pneumatic brake means operatively connected to said drum, a distributor valve pneumatically connected on the one hand to said pneumatic source of power and further being pneumatically connected to said stop valve means and said pneumatic brake, whereby when said stop valve means is actuated it also effects a pneumatic communication of said pneumatic brake with said pneumatic source of power via said distributor valve, thereby activating said pneumatic brake and braking the movement of said drum.

3 In a hoisting installation of the character described having a pneumatic source of power, a travel limiting mechanism as set forth in claim 2, including means operatively connecting said drum to said first valve member, said means comprising adjustable gear means operatively connecting said drum, a lever pivotally mounted in said travel mechanism adjacent to said pneumatic stop valve means, said lever being adapted to be tripped by said first valve member, a threaded rod rotatably mounted adja: cent to said lever and being operatively connected to said adjustable gear means so as to be rotated by them, a nut threadably mounted on said rod and adapted to move to and fro on said rod depending on the direction of rotation thereof, said nut being adapted to trip said lever when said drum has passed said preselected limit position.

4. In a hoisting installation of the character described having a pneumatic source of power, a travel limiting mechanism as set forth in claim 3, including a changeover valve mounted on the one hand, between said pneumatic source of power and said distributor valve and being pneumatically connected thereto, and on the other hand, between said stop valve means and said distributor valve and being pneumatically connected thereto.

References Cited UNITED STATES PATENTS 774,767 11/1904 Lyon. 963,384 7/1910 Ogle. 1,452,964 4/1923 Falkenau. 2,376,019 5/1945 Thomas. 2,502,710 4/1950 Duncan 254173 2,656,027 10/ 1953 Crookston.

SAMUEL F. COLEMAN, Primary Examiner.

Claims (1)

1. IN A HOISTING INSTALLATION OF THE CHARACTER DESCRIBED HAVING A PNEUMATIC SOURCE OF POWER, A TRAVEL LIMITING MECHANISM INCLUDING A DRUM FOR SPOOLING A CABLE THEREON WHICH IS OPERATIVELY MOUNTED IN SAID INSTALLATION; A PNEUMATICALLY ACTUATED CLUTCH OPERATIVELY CONNECTED TO SAID DRUM; STOP VALVE MEANS HAVING AN INLET AND OUTLET; A FIRST VALVE MEMBER RECIPROCALLY MOUNTED IN SAID STOP VALVE MEANS AND RESPONSIVE TO ROTATION OF SAID DRUM; PNEUMATIC RELAY VALVE MEANS HAVING A FIRST INLET, A FIRST OUTLET, A SECOND INLET, AND A SECOND OUTLET; THE FIRST INLET OF SAID PNEUMATIC RELAY VALVE MEANS BEING IN COMMUNICATION WITH THE OUTLET OF SAID STOP VALVE MEANS, THE INLET OF SAID STOP VALVE MEANS BEING IN COMMUNICATION WITH SAID PNEUMATIC SOURCE OF POWER AND THE FIRST OUTLET OF SAID PNEUMATIC RELAY VALVE MEANS BEING IN COMMUNICATION WITH SAID PNEUMATICALLY ACTUATED CLUTCH AND WITH SAID SECOND INLET; SAID SECOND INLET BEING IN COMMUNICATION WITH SAID PNEUMATIC SOURCE OF POWER; A SECOND VALVE MEMBER RECIPROCALLY MOUNTED IN SAID RELAY VALVE MEANS; SAID FIRST AND SECOND VALVE MEMBERS BEING ADAPTED TO RESPECTIVELY COOPERATE WITH THE INLETS AND OUTLETS OF SAID STOP VALVE MEANS AND PNEUMATIC RELAY VALVE MEANS SO THAT WHEN SAID FIRST VALVE MEMBER IS ACTED ON BY SAID DRUM IT MOVES IN SAID STOP VALVE MEANS FROM A POSITION WHEREIN THE INLET AND OUTLET THEREOF ARE NOT IN COMMUNICATION WITH EACH OTHER TO A POSITION WHEREIN THE INLET AND OUTLET THEREOF ARE IN COMMUNICATION WITH EACH OTHER, THEREBY PLACING THE FIRST INLET OF SAID RELAY VALVE MEANS INCOMMUNCIATION WITH SAID PNEUMATIC SOURCE OF POWER, VIA THE INLET AND OUTLET OF SAID STOP VALVE MEANS, SAID PNEUMATIC SOURCE OF POWER THEREBY ACTING ON SAID SECOND VALVE MEMBER AND OPERATIVELY MOVING THE LATTER FROM A POSITION IN WHICH THE FIRST OUTLET THEREOF IS IN COMMUNICATION WITH SAID PNEUMATIC SOURCE OF POWER VIA THE SECOND INLET THEREOF TO A POSITION WHEREIN SAID FIRST OUTLET IS IN COMMUNICATION WITH SAID SECOND OUTLET.

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