Safety lock device for pump-jack

Abstract

A safety lock device is used with a pump jack having a gear box and at least one rotating member having spokes (a sheave) or holes (a solid cast wheel). The safety lock device includes an engagement member which can be actuated between an unlocked position to a locked position, and is configured for securely engaging at least one spoke or hole of the rotating member to prevent any further substantial rotation of the rotating member. The safety lock device further includes a mounting frame including a housing for receiving and accommodating the engagement member for slidable movement therein and for enclosing actuation means; and bracket means for securely mounting to the gear box.

Description

[0001] SAFETY LOCK DEVICE FOR PUMP-JACK

[0002] Field of the Invention

[0003] The present invention relates to safety devices used to secure equipment in place and enable the performance of maintenance or other work on such equipment. More particularly, the invention relates to lock devices used to preclude movement of a loaded oil well pumping unit and thereby permit work on it to be performed safely.

[0004] Background of the Invention

[0005] The most common method for extracting oil from underground reservoirs is an oil well pumping unit known as the “walking beam” or “pump-jack” type (also known as nodding donkey, pumping unit, horsehead pump, rocking horse, beam pump, dinosaur, sucker rod pump, grasshopper pump, thirsty bird jack pump, popping johnny or walking beam pump - collectively referred herein as pump-jack). The pump-jack serves as the overground drive for a reciprocating piston pump downhole in an oil well, and is typically used to mechanically lift liquid out of the well when bottomhole pressure is insufficient for the liquid to flow to the surface. The pump-jack converts the rotary mechanism of a motor to a vertical reciprocating motion to drive the pump shaft, and is exhibited in the characteristic nodding motion.

[0006] Modem pump-jacks are powered by a prime mover which may be an electric motor or internal combustion engines in isolated locations without access to electricity. Common off-grid pump-jack engines run on casing gas produced from the well, but pump-jacks have been run on many types of fuel, such as propane and diesel. In harsh climates, such motors and engines may be housed in a shack for protection from the elements.

[0007] The prime mover of the pump-jack runs a set of pulleys or sheaves, via a belt, to the transmission or gear box which drives a pair of cranks, generally with counterweights on them to assist the motor in lifting the heavy string of rods. The cranks raise and lower one end of an I- beam or pump arm which is free to move on an A-frame. On the other end of the beam, there is a curved metal box called a Horse Head or Donkeys Head. A cable made of steel or fiberglass, called a bridle, connects the horse head to the polished rod, a piston that passes through the stuffing box down the well to actuate the downhole pump. The polished rod has a close fit to the stuffing box, letting it move in and out of the tubing without fluid escaping. The bridle follows the curve of the horse head as it lowers and raises to create a nearly vertical stroke. The polished rod is connected to a long string of rods called sucker rods, which run through the tubing to the downhole pump, usually positioned near the bottom of the well.

[0008] During regular maintenance or modification of a pump-jack, the pump arm is typically operated through its up-down cycle until the pump arm brings the pump head down to its lowest position, closest to the ground. At this point, the unit is stopped and a safety hand brake may be applied. Typically, the safety brake is attached to an axle that is common to the pulley or sheave on the gear box (i.e., with the sheave on one side of the gear box and the brake attached to the axle at the other side of the gear box). However, such a brake is normally a drum brake which relies on friction to prevent the various heavy components of a pump-jack from moving. Such drum brakes are known to slip, thereby creating a safety hazard. As such, in current practice, a chain may also be passed over the pump arm, and / or through the sheave at the gear box, and then secured to the platform or base of the pump unit using a boomer.

[0009] The addition of this secured chain provides some added degree of safety, should the brake mechanism fail, because it does not rely on friction but, rather, locks the moving component directly. However, this method of using a chain also has disadvantages including: (i) that an operator has to enter physically close to the pump-jack to apply the chain, thereby placing him inside the rotation area, which area is often fenced off or enclosed for safety reasons because of the heavy weights and large moving equipment involved; and (ii) that a chain through the sheave and then secured to the base will impede or prevent replacement of the belt, should such replacement be part of the pump-jack maintenance.

[0010] United States Patent No. 9,574,625 to Atabec Safety Lock Corp, describes a safety lock device for use with a pump-jack. However, the safety lock device needs to be custom fit for each installation, requiring laborious and time-consuming cutting, grinding, and drilling onsite. In addition, the safety lock device is manufactured as one piece from mild carbon steel, rendering it heavy and cumbersome to move without the use of machinery. The hydraulic components are exposed to the environment which increases the risk of damage from the elements, thereby necessitating costly repair or replacement.

[0011] Accordingly, there remains a need for an improved safety lock device which may overcome the shortcomings of prior art safety lock devices. Summary of the Invention

[0012] The present invention relates to an improved safety lock device for a pump-jack.

[0013] In a first aspect, the invention comprises a safety lock device for use with a pump-jack having a gear box and at least one rotating member having spokes or holes, the safety lock device comprising: an engagement member actuatable between an unlocked position to a locked position, wherein the engagement member is configured for securely engaging at least one spoke or hole of the rotating member to prevent any further substantial rotation of the rotating member; and a mounting frame comprising a housing for receiving and accommodating the engagement member for slidable movement therein and for enclosing actuation means; and bracket means for securely mounting to the gear box.

[0014] In some embodiments, the rotating member is selected from a sheave or a solid cast wheel.

[0015] In some embodiments, the engagement member comprises a longitudinal sliding member having a longitudinal axis and a pair of pins projecting parallel to the longitudinal axis and forming a spoke channel therebetween. In some embodiments, the spoke channel accommodates the spoke at a slightly greater depth than the depth of the spoke. In some embodiments, at least one pin engages the hole of the solid cast wheel.

[0016] In some embodiments, the pump-jack defines a rotation area and wherein the actuation means comprises at least one hydraulic ram cylinder associated with the engagement member; one or more hydraulic pumps to actuate the at least one hydraulic ram cylinder to move the engagement member between the locked position and the unlocked position; and suitable lengths of hydraulic lines, so as to position the one or more hydraulic pumps outside the rotation area.

[0017] In some embodiments, the housing is configured with at least one opening in at least one wall for routing the hydraulic lines to the one or more hydraulic pumps outside the rotation area.

[0018] In some embodiments, the housing comprises a front wall, back wall, top wall, bottom wall, open end, and closed end, which together define a passage extending therethrough for receiving and accommodating the engagement member and the actuation means.

[0019] In some embodiments, the open end comprises a plate which defines an opening corresponding to dimensions of the engagement member for allowing entry of the engagement member into the passage, the plate including tapered edges for restricting advancement of the engagement member fully into the passage.

[0020] In some embodiments, the front wall comprises a panel comprising a handle and hingedly connected to the bottom wall for access to the actuation means.

[0021] In some embodiments, the bracket means comprises a top bracket and a bottom bracket for securely mounting to the gear box.

[0022] In some embodiments, the back wall defines a central slot configured to align with a corresponding central slot of the top bracket for slidably mounting the engagement member, and apertures for receiving attachment means therethrough to connect to the top bracket.

[0023] In some embodiments, the top bracket comprises a front plate comprising spacer tabs along an upper edge, and retaining means along a lower edge for gripping the housing and hydraulic lines.

[0024] In some embodiments, the top bracket further comprises attachment means extending outwardly from a back surface of the front plate and comprising plate hooks and hook rings to receive wedge pipes for mounting to the gear box.

[0025] In some embodiments, the bottom bracket comprises a front plate, back plate, and comer braces, the front plate defining cutouts, and the back plate extending perpendicularly from a back surface of the front plate, the front and back plates defining holes for receiving attachment means therethrough.

[0026] In some embodiments, a narrow portion receives the engagement member, and a wide portion comprises a side plate positioned between the narrow portion and the wide portion, a top plate, the closed end, and a panel comprising a handle and hingedly connected to either the back wall for side access or the top plate for top access to the actuation means.

[0027] In some embodiments, the back wall defines a pair of spaced apart hinge slots for accommodating a corresponding pair of hinges, and the panel is lockable by inserting suitable locking means through a first lock tab and a corresponding second lock tab defined by the closed end.

[0028] In some embodiments, the bracket means comprises a pair of angled brackets configured for attachment to the back wall and securable to the gear box of the pump-jack. In some embodiments, the safety lock device further comprises upper braces defining openings through which lifting means extend therethrough for lifting or moving the safety lock device.

[0029] In some embodiments, the engagement member, housing, and bracket means are formed of high tensile lightweight steel.

[0030] Additional aspects and advantages of the present invention will be apparent in view of the description which follows. It should be understood, however, that the detailed description and the specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the scope of the invention will become apparent to those skilled in the art from this detailed description.

[0031] The invention will now be described by way of an exemplary embodiment with reference to the accompanying simplified, diagrammatic, not-to-scale drawings. In the drawings:

[0032] FIGS. 1A-B (PRIOR ART) are perspective views of a conventional pump-jack and prior art safety lock device mounted thereon.

[0033] FIG. 2A is a perspective view of components of a conventional pump-jack and an improved safety lock device of the present invention being mounted on the gear box manually by a technician.

[0034] FIGS. 2B-C are perspective views of the safety lock device shown in FIG. 2 A mounted on the gear box.

[0035] FIGS. 2D-E are perspective views of a conventional sheave and a safety lock device of the present invention in the locked position (FIG. 2D) and unlocked position (FIG. 2E).

[0036] FIG. 3 is an exploded perspective view of a first embodiment of the safety lock device, showing all components in detail.

[0037] FIG. 4 is a perspective view of the safety lock device shown in FIG. 3 fully assembled.

[0038] FIG. 5 is a front view of the safety lock device shown in FIG. 4.

[0039] FIG. 6 is a right side view of the safety lock device shown in FIG. 4.

[0040] FIG. 7 is an exploded perspective view of a second embodiment of the safety lock device, showing all components in detail.

[0041] FIG. 8 is a perspective view of a top plate and stop mounted thereon. FIG. 9 is a perspective view of a closed end defining a locking tab and lugs mounted thereon.

[0042] FIG. 10 is a perspective view of a housing.

[0043] FIG. 11 shows an exploded perspective view of an engagement member, showing all components in detail, and the engagement member fully assembled.

[0044] FIG. 12A is a perspective view of the safety lock device shown in FIG. 7 fully assembled.

[0045] FIG. 12B is a front view of the safety lock device of FIG. 12 A.

[0046] FIGS. 13A-B are perspective views of exemplary angled brackets for mounting the safety lock device to the gear box of the pump-jack.

[0047] FIG. 14 is a perspective view of a conventional sheave and a third embodiment of the safety lock device in the locked position.

[0048] Detailed Description of Preferred Embodiments

[0049] Before the present invention is described in further detail, it is to be understood that the invention is not limited to the particular embodiments described, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting, since the scope of the present invention will be limited only by the appended claims.

[0050] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention, a limited number of the exemplary methods and materials are described herein. As used herein, the term “horizontal” means the orientation of a plane or line that is substantially parallel to the plane of the horizon. The term “vertical” means the orientation of a plane or line that is substantially at a right angle to the horizontal plane. The terms “front” and “back” are used to describe the positions of various components of the safety lock device. The term “front” refers to a position away from the gear box of the pump-jack. The term “back” refers to a position closer to the gear box of the pumpjack.

[0051] United States Patent No. 9,574,625 to Atabec Safety Lock Corp, describes a safety lock device (1) installed on a pump-jack (2), as shown in FIGS. 1A-B (PRIOR ART). As is conventional, pump-jack (2) includes a frame (3) and walking beam (4) pivotably supported above the frame (3) by a samson post (6) for pivotal movement about a horizontal axis defined by a center bearing assembly or saddle bearing (8). The beam has a pitman assembly or crank rods (9) connected to the beam (4) at one end (5). The pitman assembly (9) is driven to cause the beam (4) to oscillate or pivot in a vertical plane about the transverse horizontal axis of the saddle bearing (8). The other end (7) of the beam (4) has a horsehead (10) connected thereto. The horsehead (10) has cables, a bridle, hanger assembly or other well pumping tools (not shown) connected thereto.

[0052] The pitman assembly (9) is driven by a motor (11) or prime mover adjacent one end of the frame (3). Motor (11) runs a belt (12) over a set of pulleys or sheaves (13a, 13b) to power the gear box or transmission (14) which drives a pair of cranks (16) with counterweights (17) on them to assist the motor (11) in lifting the heavy string of rods. Sheave (13b) is mounted at one side of the gearbox (14) via axle (15) and includes spokes (18). Alternatively, the pulley or sheave (13b) may be a web-type sheave having one or more through-openings in the sheave surface rather than spokes (18). Axle (15) rotates about a horizontal axis of rotation, with the axle (15) being offset but parallel to the horizontal axis of the saddle bearing (8). A safety drum brake (not shown) may be attached to axle (15), forbraking of the pump-jack (2), as the axle (15) passes through gear box (14) and exits at a side opposite to that of sheave (13b) (exiting portion not shown). Axle (15) is common to the sheave (13b) on the gearbox (14) and to the safety drum brake, i.e., with the sheave (13b) on one side of the gear box (14) and the brake drum attached to the axle (15) at the other side of the gear box (14). In some embodiments, a solid cast wheel comprising one or more holes may be used instead of the sheave (13b).

[0053] However, the aforementioned prior art safety lock device (1) needs to be custom fit for each installation, requiring laborious and time-consuming cutting, grinding, and drilling onsite. In addition, the safety lock device (1) is manufactured as one piece from mild carbon steel, rendering it heavy and cumbersome to move without the use of machinery. The hydraulic components (19) are exposed to the environment which increases the risk of damage from the elements, thereby necessitating costly repair or replacement.

[0054] The present invention relates to an improved safety lock device (20) for a conventional pump-jack (2). The safety lock device (20) has a modular, lightweight design to facilitate easy assembly, rapid installation, and manual handling, and is compatible for use with all current makes and models of pump-jack on the global market. Any hydraulic components are protected from the elements, increasing longevity.

[0055] The invention will now be described having reference to the accompanying Figures. The safety lock device (20) of the present invention is shown installed on the pump-jack (2) in FIGS. 2B-E. The safety lock device (20) is configured to securely engage at least one of the pulleys or sheaves (13a, 13b), a solid cast wheel (not shown), or the circular rotating drum component of a brake drum (not shown), of a conventional pump-jack (2). The safety lock device (20) is further configured to actuate, preferably along a substantially horizontal axis, between: (i) a locked position, wherein it securely engages at least one of the spokes (18) of the sheave (13b), or wherein it passes through at least one of the holes in the web of the sheave, the solid cast wheel, or the circular rotating drum component of a brake drum, so as to prevent any further substantial rotation of the respective sheave, solid cast wheel, or drum brake, and (ii) an unlocked position, wherein it allows for unhindered conventional operation and rotation of the sheaves, solid cast wheel, and drum brake. As such, the safety lock device (20) of the present invention further comprises actuation means (22) to actuate the safety lock device (20) between locked and unlocked positions.

[0056] In a first embodiment, the safety lock device (20) is shown unassembled in FIG. 3 to show all its components in detail, and assembled in FIGS. 4-6 for installation on the pump-jack (2). The safety lock device (20) generally comprises a linear assemblage of components including a locking mechanism comprising an engagement member (24), and a mounting frame comprising a housing (26), a top bracket (28), and a bottom bracket (30). The engagement member (24) may be actuated between an unlocked position and a locked position for securely engaging the rotating member (i.e., sheaves (13a, 13b), solid cast wheel, or drum brake) to prevent further substantial rotation of the rotating member. The housing (26) receives and accommodates the engagement member (24) for slidable movement therein, and further encloses the actuation means (22) for protection against the environment. The top bracket (28) and bottom bracket (30) serve to mount the safety lock device (20) to the gear box (14) of the pump-jack (2).

[0057] In some embodiments, the housing (26) comprises a narrow portion (32) for receiving and accommodating the engagement member (24) for slidable movement therein, and a wide portion (34) for enclosing the actuation means (22). In some embodiments, the housing (26) is generally rectangular-shaped, and comprises a front wall (36), back wall (38), top wall (40), bottom wall (42), open end (44) and closed end (46), which together define a passage (48) extending therethrough and configured for receiving and accommodating the engagement member (24) within the narrow portion (32), and the actuation means (22) within the wide portion (34).

[0058] The front wall (36) is recessed to form the narrow portion (32) to correspond to the dimensions of the engagement member (24). The front wall (36) extends outwardly to form the wide portion (34) to correspond to the dimensions of the actuation means (22), and comprises a panel (50) hingedly connected to the bottom wall (42) and having a handle (52) which may be gripped and pulled downwardly by a technician to open the panel (50) to access the actuation means (22) for assembly, maintenance, or repair, and to close the panel (50) to protect the actuation means (22) from the environment, thereby ensuring longevity of the actuation means (22). Various labels (54) may be attached to the panel (50) including, for example, manufacturing labels, notice labels, certification stickers, and the like.

[0059] The back wall (38) is configured to extend partially above the top wall (40), and defines a central slot (56) which is configured to align with the corresponding central slot (58) of the top bracket (28) for slidably mounting the engagement member (24). Apertures (60) extend through the back wall (38) for receiving attachment means therethrough. In some embodiments, the attachment means are short cap screws (62). In some embodiments, apertures (60) are positioned in a spaced apart manner in rows, with a top row opposed and aligned with a bottom row. The rows of apertures (60) align with corresponding rows of apertures (64) of the top bracket (28). In some embodiments, there are three apertures in each row. In some embodiments, the housing (26) is secured to the top bracket (28) using six short cap screws (62) threaded through the apertures (60).

[0060] Upper braces (66) anchor the back wall (38) to the top wall (40), and define openings (68) through which chains, cable, rope, straps, and the like may be threaded therethrough to facilitate lifting or moving of the safety lock device (20) during assembly, installation, or use.

[0061] Lower braces (70) anchor the back wall (38) to the bottom wall (42), and provide support. The bottom wall (42) defines an opening (72) to route hydraulic lines (74) associated with the actuation means (22) to a cable clip (76) which grips and separates the hydraulic lines (74) in an organized manner.

[0062] The open end (44) comprises a plate which defines an opening (78) that corresponds to the dimensions of the engagement member (24) to allow entry of the engagement member (24) into the passage (48). The plate includes tapered edges (80) which extend beyond the top and bottom walls (40, 42) to act as a barrier, restricting advancement of the engagement member (24) fully into the passage (48). In some embodiments, the opening (78) is substantially rectangular-shaped.

[0063] In some embodiments, the engagement member (24) comprises a longitudinal sliding member having a longitudinal axis A, a first end (82), a second end (84), and a body (86) disposed between the first and second ends (82, 84) (FIG. 11). In some embodiments, the first end (82) is prong-shaped, comprising a pair of pins (88a, 88b) projecting substantially parallel to the longitudinal axis A, and forming a spoke channel (90) therebetween. In some embodiments, the first end (82) comprises a substantially “I”-shaped plate (91) which is configured to define the pins (88a, 88b), the spoke channel (90), the sloped edges (92a, 92b), and a channel (93). Upper edge plates (95a) and lower edge plates (95b) are configured to align with the sloped edges (92a, 92b), thereby reinforcing the pins (88a, 88b). The sloped edges (92a, 92b) of the pins (88a, 88b) abut against the tapered edges (80) of the plate, thereby barring the first end (82) from advancing into the passage (48).

[0064] The body (86) is configured to correspond to the dimensions of the passage (48), and to slidably fit through the open end (44) for longitudinal sliding movement within the passage (48), thereby actuating the engagement member (24) between the locked and unlocked positions. In some embodiments, the body (86) is substantially rectangular-shaped. In some embodiments, the body (86) defines a ledge (87) at a first body end (89) to receive the channel (93) of the “I”-shaped plate (91). An end cap (97) caps the body (86) at a second body end (99). In some embodiments, the body (86) is configured to protrude slightly outwardly to engage the central slots (56, 58) of the housing (26) and the top bracket (28).

[0065] The second end (84) comprises connection means for connecting to the actuation means (22). In some embodiments, the connection means comprises a pair of opposed lugs (101) defining one or more holes (94) for receiving attachment means to connect the engagement member (24) to the actuation means (22). In some embodiments, the lugs (101) are attached to the end cap (97) which caps the second body end (99) of the body (86).

[0066] In some embodiments, the actuation means (22) comprises at least one hydraulic ram cylinder (96) connected to the engagement member (24), and suitable lengths of hydraulic lines (74) to position one or more hydraulic pumps (not shown) away from the pump-jack (2) and outside the rotation area. In some embodiments, there is a single hydraulic ram cylinder (96) for actuating the engagement member (24) into the locked and the unlocked positions. Hydraulic ram cylinders (96) are well known in the art and will not be described in detail. Briefly, the hydraulic ram cylinder (96) comprises a bushing (98), a piston rod (100), a rod-end head (102), a barrel (104) housing a piston (not shown), and a cap-end head (106). In some embodiments, the engagement member (24) is connected to the hydraulic ram cylinder (96) by passing a pin (108) through the second end (84) and the bushing (98) of the hydraulic ram cylinder (96) and securing with a screw (110) and hex nut (111). In some embodiments, the hydraulic ram cylinder (96) is enclosed within the wide portion (34) of the housing (26), secured using a pin (108) tightened by a screw (110), and is accessed via the panel (50).

[0067] The hydraulic lines (74) are routed through the opening (72) in the bottom wall (42) to the cable clip (76) on the top bracket (28). The hydraulic ram cylinder (96) converts hydraulic energy into linear movement and is used to actuate the engagement member (24) between the locked position, wherein it extends linearly from the passage (48) to engage the rotating member to prevent further substantial rotation of the rotating member, to the unlocked position, wherein it retracts into the passage (48) to disengage the rotating member to allow further substantial rotation of the rotating member.

[0068] The top bracket (28) comprises a front plate (112) and a back plate (114). The front plate (112) comprises a top portion (116) and a bottom portion (118) which are bifurcated by the central slot (58), a side portion (120) which adjoins the top and bottom portions (116, 118), a front surface (122), and a back surface (124). The top portion (116) supports spacer tabs (126) which are distributed evenly in a spaced apart manner along the edge of the top portion (116). In some embodiments, a pair of spacer tabs (126) are provided. In some embodiments, the spacer tabs (126) are rectangular-shaped. The spacer tabs (126) are configured to regulate the spacing between the top bracket (28) and the housing (26) when the safety lock device (20) is assembled.

[0069] The bottom portion (118) comprises support clips (128) which extend upwardly and slightly outwardly from the front surface (122). The support clips (128) are configured to support the housing (26) which is retained within the support clips (128). In some embodiments, a pair of clips (128) is provided to support the housing (26).

[0070] The side portion (120) is substantially square-shaped and defines a shoulder cutout (130) on an upper corner. The shoulder cutout (130) is configured to align parallel with a corresponding shoulder cutout (132) of the housing (26) when the safety lock device (20) is assembled. The side portion (120) supports the cable clip (76) which is mounted on the lower comer of the front surface (122) for cable management. In some embodiments, the cable clip (76) defines holes (134) to allow the hydraulic lines (74) to pass therethrough. In some embodiments, the cable clip (76) is configured with a pair of holes (134). The cable clip (76) thereby grips and separates the hydraulic lines (74) in an organized manner, preventing them from becoming tangled together or caught in other components of the pump-jack (2) when the safety lock device (20) is in use. The hydraulic lines (74) are associated with the hydraulic ram cylinder (96) enclosed within the housing (26).

[0071] The bottom and side portions (118, 120) further comprise hook rings (136) which extend outwardly from the back surface (124), and are positioned in a spaced apart manner and in alignment with corresponding cutouts (138) of the bottom bracket (30) when the safety lock device (20) is assembled. In some embodiments, there are two pairs of hook rings (136), one pair disposed on the bottom portion (118) and the other pair disposed on the side portion (120). The hook rings (136) are configured to hold wedge pipes (140) when the safety lock device (20) is assembled. The wedge pipes (140) ensure proper gap dimensions between the safety lock device (20) and the gear box (14), and enable attachment of the safety lock device (20) to the gear box (14).

[0072] The back plate (114) extends perpendicularly from the center of the back surface (124) of the front plate (112), and supports plate hooks (142). In some embodiments, there are two pairs of plate hooks (142), with each pair positioned in a spaced apart manner. Each pair of plate hooks (142) is configured to receive and accommodate a wedge pipe (144). In some embodiments, each plate hook (142) comprises a circular-shaped aperture (146) for receiving and accommodating a corresponding wedge pipe (144) in an orientation parallel to the back plate (114), and a washer plate (148) positioned perpendicular to the wedge pipe (144) for receiving attachment means to secure the wedge pipe (144) to the plate hook (142). In some embodiments, the wedge pipes (144) are secured to the plate hooks (142) by cap screws (150) and complementary hex nuts (152). In some embodiments, four plate hooks (142), four washer plates (148), and two wedge pipes (144) are provided. The wedge pipes (144) are secured using the cap screws (150) extending through the holes of the washer plates (148) and wedge pipes (144), and complementary hex nuts (152).

[0073] The top bracket (28) is secured to the housing (26) by suitable attachment means. In some embodiments, apertures (64) extend through the front plate (112) for receiving attachment means therethrough. In some embodiments, the attachment means are the short cap screws (62). In some embodiments, apertures (64) are positioned in a spaced apart manner in rows, with a top row in the top portion (116) opposed and aligned with a bottom row in the bottom portion (118). The rows of apertures (64) align with corresponding rows of apertures (60) of the housing (26). In some embodiments, there are three apertures in each row. In some embodiments, the top bracket (28) is secured to the housing (26) using six short cap screws (62) threaded through both sets of apertures (60, 64). In some embodiments, additional apertures (153) are positioned in a spaced apart manner in a row below apertures (64). In some embodiments, there are four apertures (153). Apertures (153) receive attachment means to secure the top bracket (28) to the bottom bracket (30).

[0074] The bottom bracket (30) comprises a front plate (154), back plate (156), and corner braces (158) anchoring the front plate (154) and the back plate (156). The front plate (154) defines a pair of bottom cutouts (138) and a top cutout (160) positioned between the bottom cutouts (138). The top and bottom cutouts (160, 138) are configured for receiving and accommodating components of the top bracket (28). In some embodiments, the bottom cutouts (138) are substantially identical and square-shaped. In some embodiments, the top cutout (160) is substantially rectangular-shaped. A hole (162) is positioned on each side of each bottom cutout (138). The holes (162) extend through the front plate (154) for receiving attachment means. In some embodiments, the holes (162) extend through the front plate (154) for receiving elongated cap screws (164) therethrough which are secured by complementary hex nuts (166). In some embodiments, four holes (162) and the holes of two wedge pipes (140) receive four elongated cap screws (164) which are secured by four hex nuts (166), thereby facilitating compression and assemblage of the components of the safety lock device (20), as shown in FIGS. 4-6. The elongated cap screws (164) also pass through the apertures (153) of the top bracket (28), thereby securing the top bracket (28) to the bottom bracket (30).

[0075] The back plate (156) extends perpendicularly from the center of the front plate (154) and defines holes (168) which are evenly distributed in a spaced apart manner from adjacent holes (168) over a portion or the entirety of the back plate (156). The holes (168) extend through the back plate (156) for receiving attachment means. In some embodiments, the holes (168) extend through the back plate (156) for receiving threaded rods (170) therethrough which are secured by washer plates (172) and complementary hex nuts (174). In some embodiments, five holes (168) receive five threaded rods (170) which are secured using ten washer plates (172) and twenty hex nuts (174). The safety lock device (20) can be constructed from any material or combination of materials having suitable properties such as, for example, mechanical strength, ability to withstand cold and adverse field conditions, corrosion resistance, and ease of machining and handling. In some embodiments, the engagement member (24), housing (26), top bracket (28), and bottom bracket (30) are formed of high tensile lightweight steel, making the safety lock device (20) considerably lightweight compared to prior art devices formed of other materials heavier than high tensile lightweight steel. Being lightweight allows the safety lock device (20) to be moved manually by a technician rather than by machinery (FIG. 2A). Various attachment means (e.g., the elongated and short cap screws, threaded rods, hex nuts, pins, and wedge pipes) may be formed of steel, for example, stainless steel, carbon steel, and strength-bearing materials. Hydraulic ram cylinders are well known and commercially available.

[0076] The safety lock device (20) has a modular design facilitating easy assembly. The top bracket (28) is guided into its proper position by inserting the hook rings (136) through the cutouts (138) of the bottom bracket (30). The housing (26) is guided into its proper position by aligning the shoulder cutout (132) of the housing (26) parallel with the corresponding shoulder (130) of the top bracket (28). The bottom bracket (30), top bracket (28), and housing (26) are pieced or compressed together using attachment means including, but not limited to, various sizes of cap screws (62, 110, 150, 164), threaded rods (170), pins (108), hex nuts (152, 166, 174), washer plates (172), and the like. The engagement member (24) is slid into the passage (48) and attached to the hydraulic ram cylinder (96) by opening the panel (50) to attach the second end (84) of the engagement member (24) to the bushing (98) of the hydraulic ram cylinder (96). The hydraulic lines (74) associated with the hydraulic ram cylinder (96) are routed from the housing (26) through the cable clip (76) to the associated hydraulic pumps (not shown).

[0077] The bottom bracket (30) is configured to mate with all current makes and models of pumpjacks on the global market. The safety lock device (20) aligns with existing bolt patterns on the gear box (14) to enable installation within minutes rather than multiple hours to days as necessary with prior art devices. The wedge pipes (140, 144) enable secure attachment of the safety lock device (20) to the gear box (14), while ensuring the proper gap dimensions between the safety lock device (20) and the gear box (14). During the development of the present invention, it was found that installation time for the safety lock device (20) to the gear box (14) was about thirty minutes. Once the safety lock device (20) is properly installed, the hydraulic ram cylinder (96) converts hydraulic energy into linear movement and is used to actuate the engagement member (24) in a slidable manner between the locked position and unlocked position. In the locked position shown in FIGS. 2B and 2D, the engagement member (24) is extended linearly from the passage (48) of the housing (26) to engage the rotating member (i.e., sheaves (13a, 13b), solid cast wheel, or drum brake) to prevent further substantial rotation of the rotating member. In some embodiments, the spoke channel (90) of the engagement member (24) accommodates any one of the spokes (18) of the rotating member (e.g., sheave (13a, 13b)) therein. In a conventional pumpjack (2), the sheaves (13a, 13b) typically have spokes (18) that are substantially identical in dimensions. Preferably, the spoke channel (90) accommodates a spoke (18) at a slightly greater depth than the depth of the spoke (18). In some embodiments, one or more of the pins (88a, 88b) of the engagement member (24) pass through at least one or more of the holes in the solid cast wheel to prevent further substantial rotation of the solid cast wheel. Advantageously, because the sheaves (13a, 13b) or solid cast wheel are operationally connected to the various moving and rotating parts of a pump-jack (such as the crank rods (9) or horse-head (10)), i.e., via gearbox (14), by preventing any further substantial rotation of the sheave (13 a, 13b) or the solid cast wheel, the remainder of the moving parts of the pump-jack (2) are likewise prevented from moving. More advantageously, because the engagement member (24) passes through the sheave (13a, 13b) or the solid cast wheel, and directly engages and blocks rotation of the sheave (13a, 13b) or the solid cast wheel, it does not have the risk of slippage as would be the case with a drum brake that uses friction.

[0078] In the unlocked position shown in FIG. 2E, the engagement member (24) is retracted into the passage (48) of the housing (26) to disengage the rotating member (e.g., the sheave (13b) or the solid cast wheel) to allow further substantial rotation of the rotating member.

[0079] It should be apparent, however, to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein.

[0080] In a second embodiment, the safety lock device (200) is shown unassembled in FIGS. 7- 10 to show all its components in detail, and assembled in FIGS. 12A-12B for installation on the pump-jack (2). The safety lock device (200) generally includes the same features as the first embodiment of the safety lock device (20), except for modifications to the housing (26). In some embodiments, the housing (26) comprises a narrow portion (32) for receiving and accommodating the engagement member (24) for slidable movement therein, and a wide portion (34) for enclosing the actuation means (22). In some embodiments, the housing (26) is generally rectangular-shaped, and comprises a front wall (36), back wall (38), top wall (40), bottom wall (42), open end (44) and closed end (46), which together define a passage (48) extending therethrough and configured for receiving and accommodating the engagement member (24) within the narrow portion (32), and the actuation means (22) within the wide portion (34).

[0081] The front wall (36) is recessed to form the narrow portion (32) to correspond to the dimensions of the engagement member (24). The wide portion (34) extends outwardly and corresponds to the dimensions of the actuation means (22), and comprises a substantially “L”- shaped side plate (35), a top plate (37), the closed end (46), and the panel (50). The side plate (35) is positioned between the narrow portion (32) and the wide portion (34). The top plate (37) defines openings (39) for receiving attachment means therethrough. In some embodiments, the attachment means comprise locking bolts (41) and short cap screws (62).

[0082] The panel (50) is hingedly connected to the back wall (38) which defines a pair of spaced apart hinge slots (43) for accommodating a corresponding pair of hinges (45). The top plate (37) comprises a stop (47) mounted thereon and against which the panel (50) abuts when closed (FIG. 8). The panel (50) has a handle (52) which may be gripped and pulled downwardly by a technician to open the panel (50) to access the actuation means (22) for assembly, maintenance, or repair, and to close the panel (50) to protect the actuation means (22) from the environment, thereby ensuring longevity of the actuation means (22). In some embodiments, the hydraulic ram cylinder (96) is enclosed within the wide portion (34) of the housing (26), attached to the closed end (46) by a pair of lugs (113), secured using pins (108) tightened by nuts and bolts (115), and is accessed via the panel (50). The panel (50) may be locked by inserting suitable locking means (for example, a screw, bolt, and the like) through a first lock tab (51) and a corresponding second lock tab (53) defined by the closed end (46). Various labels (54) may be attached to the panel (50) including, for example, manufacturing labels, notice labels, certification stickers, and the like.

[0083] In some embodiments, a spacer (57) is mounted on the back wall (38) to be positioned between the back wall (38) and the body (86) of the engagement member (24) when assembled. Apertures (60) extend through the back wall (38) for receiving attachment means therethrough. In some embodiments, apertures (60) are positioned at each corner of the back wall (38). In some embodiments, the back wall (38) is attached to angled brackets (59) (FIGS. 13 A-B) using suitable attachment means (61) (for example, bolts and the like) threaded through the apertures (60) of the back wall and corresponding apertures (63) of the angled brackets (59). In turn, the angled brackets (59) are secured to the gear box (14) of the pump-jack (2) using larger bolts (65), and define slots (67) to engage the gear box (14).

[0084] Upper braces (66) anchor the back wall (38) to the top wall (40), and define openings (68) through which chains, cable, rope, straps, and the like may be threaded therethrough to facilitate lifting or moving of the safety lock device (20) during assembly, installation, or use. Lower braces (70) anchor the back wall (38) to the bottom wall (42), and provide support.

[0085] The open end (44) comprises a plate which defines an opening (78) that corresponds to the dimensions of the engagement member (24) to allow entry of the engagement member (24) into the passage (48). The plate includes tapered edges (80) which act as a barrier, restricting advancement of the engagement member (24) fully into the passage (48). In some embodiments, the opening (78) is substantially rectangular-shaped.

[0086] In a third embodiment, the safety lock device (300) is shown in FIG. 14 mounted on the pump-jack (2). The safety lock device (300) generally includes the same features as the second embodiment of the safety lock device (20), except for a modified housing (26). The panel (50) is hingedly connected to have the handle (52) facing upwardly. The first lock tab (51) and second lock tab (53) defined by the closed end (46) face upwardly. The opening (72) through which the hydraulic lines (74) are routed is positioned on a side wall.

[0087] It should be apparent, however, to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter is not to be restricted except in the scope of the disclosure. Moreover, in interpreting the disclosure, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. As used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. In addition, the components and steps described in the above embodiments and figures are merely illustrative and do not imply that any particular component or step is a requirement of a claimed embodiment.

Claims

WHAT IS CLAIMED IS:

1. A safety lock device for use with a pump-jack having a gear box and at least one rotating member having spokes or holes, the safety lock device comprising: an engagement member actuatable between an unlocked position to a locked position, wherein the engagement member is configured for securely engaging at least one spoke or hole of the rotating member to prevent any further substantial rotation of the rotating member; and a mounting frame comprising a housing for receiving and accommodating the engagement member for slidable movement therein and for enclosing actuation means; and bracket means for securely mounting to the gear box.

2. The safety lock device of claim 1, wherein the rotating member is selected from a sheave or a solid cast wheel.

3. The safety lock device of claim 2, wherein the engagement member comprises a longitudinal sliding member having a longitudinal axis and a pair of pins projecting parallel to the longitudinal axis and forming a spoke channel therebetween.

4. The safety lock device of claim 3, wherein the spoke channel accommodates the spoke of the sheave at a slightly greater depth than the depth of the spoke.

5. The safety lock device of claim 3, wherein at least one pin engages the hole of the solid cast wheel.

6. The safety lock device of claim 1, wherein the pump-jack defines a rotation area and wherein the actuation means comprises at least one hydraulic ram cylinder associated with the engagement member; one or more hydraulic pumps to actuate the at least one hydraulic ram cylinder to move the engagement member between the locked position and the unlocked position; and suitable lengths of hydraulic lines, so as to position the one or more hydraulic pumps outside the rotation area.

7. The safety lock device of claim 6, wherein the housing is configured with at least one opening in at least one wall for routing the hydraulic lines to the one or more hydraulic pumps outside the rotation area.

8. The safety lock device of claim 1, wherein the housing comprises a front wall, back wall, top wall, bottom wall, open end, and closed end, which together define a passage extending therethrough for receiving and accommodating the engagement member and the actuation means.

9. The safety lock device of claim 8, wherein the open end comprises a plate which defines an opening corresponding to dimensions of the engagement member for allowing entry of the engagement member into the passage, the plate including tapered edges for restricting advancement of the engagement member fully into the passage.

10. The safety lock device of claim 9, wherein the front wall comprises a panel comprising a handle and hingedly connected to the bottom wall for access to the actuation means.

11. The safety lock device of claim 10, wherein the bracket means comprises a top bracket and a bottom bracket for securely mounting to the gear box.

12. The safety lock device of claim 11, wherein the back wall defines a central slot configured to align with a corresponding central slot of the top bracket for slidably mounting the engagement member, and apertures for receiving attachment means therethrough to connect to the top bracket.

13. The safety lock device of claim 12, wherein the top bracket comprises a front plate comprising spacer tabs along an upper edge, and retaining means along a lower edge for gripping the housing and hydraulic lines.

14. The safety lock device of claim 13, wherein the top bracket further comprises attachment means extending outwardly from a back surface of the front plate and comprising plate hooks and hook rings to receive wedge pipes for mounting to the gear box.

15. The safety lock device of claim 11, wherein the bottom bracket comprises a front plate, back plate, and corner braces, the front plate defining cutouts, and the back plate extending perpendicularly from a back surface of the front plate, the front and back plates defining holes for receiving attachment means therethrough.

16. The safety lock device of claim 9, wherein a narrow portion receives the engagement member, and a wide portion comprises a side plate positioned between the narrow portion and the wide portion, a top plate, the closed end, and a panel comprising a handle and hingedly connected to either the back wall for side access or the top plate for top access to the actuation means.

17. The safety lock device of claim 16, wherein the back wall defines a pair of spaced apart hinge slots for accommodating a corresponding pair of hinges, and the panel is lockable by inserting suitable locking means through a first lock tab and a corresponding second lock tab defined by the closed end.

18. The safety lock device of claim 17, wherein the bracket means comprises a pair of angled brackets configured for attachment to the back wall and securable to the gear box of the pumpjack.

19. The safety lock device of claim 1, further comprising upper braces defining openings through which lifting means extend therethrough for lifting or moving the safety lock device.

20. The safety lock device of claim 1, wherein the engagement member, housing, and bracket means are formed of high tensile lightweight steel.

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