Patent Description:
Helical anchors and piles are used in a variety of applications including, for example, for foundation construction and repair, securing underwater moorings, and securing and supporting utility poles. For example, when a utility pole is installed or repaired, one or more anchors may be driven into the ground adjacent to the utility pole. One end of a guy wire attaches to the utility pole and the opposite end attaches to an anchor secured in the ground.

Anchors and piles may be similarly constructed, though anchors are generally used in tension and piles are generally used in compression. This disclosure is equally applicable to both anchors and piles, and tools for installing anchors and piles, without limitation.

Helical anchors and piles typically include a central shaft or rod with helical bearing plates. Depending on the soil type and desired depth, significant torque is required to install a helical anchor or pile. Anchors and piles are generally installed using an anchor/pile drive tool powered by a utility truck, heavy equipment, or a portable drive unit. A torque indicator may be provided between an upper end of the drive tool and a hex or square output shaft. The equipment rotates the output shaft to drive the anchor or pile into the ground. The upper end of the anchor or pile and/or extension pieces to the anchor or pile are received within the drive tool and locked in place during installation.

Some exemplary drive tools, such as the Chance® locking dog assemblies offered by Applicant, are used in conjunction with a hollow drive wrench. The top of the drive wrench is received by the locking dog assembly. Spring-loaded locking dogs or pins in the locking dog assembly catch in holes in the drive wrench to releasably secure the drive wrench.

The anchor and/or extension pieces to the anchor are received within the drive wrench and locking dog assembly and locked in place during installation. Spring-loaded locking dogs or pins in the locking dog assembly catch under the head of the anchor to releasably secure the anchor in the wrench.

The locking dog springs can be damaged by a backlash event during which a large amount of stored energy is released into kinetic energy instantaneously. A backlash event may be the result of a mechanical failure, such as anchor or pile breakage, and may also occur during normal use if a shear pin torque limiter is used at high torque loads. Backlash is an extreme angular acceleration of the drive tool which abruptly throws the locking dogs outward against the springs. This often damages the springs and results in impaired locking dog function. Severely damaged springs do not securely hold the locking dogs in the engaged position and create a safety hazard due to the potential of dropping the drive wrench and/or anchor/pile.

Further, locking dog operation is often difficult due to the motion required and the position of the locking dogs when operation is needed. In existing devices, each locking dog is pushed inward along its axis and held in the engaged position by the spring which requires significant force (e.g., about <NUM> pounds) to fully compress when the locking dog is pulled out. The motion required to disengage the locking dog is generally an outward pull against the force of the spring and a rotation of the locking dog about its axis to secure it in the disengaged position via an operating ring attached to the outer end of the locking dog. The locking dog is automatically reengaged by its spring when the ring and locking dog are rotated to the proper position.

Each locking dog is typically operated independently from the other, and it is common for the act of disengaging the second locking dog to jar the tool and cause the first locking dog to reengage. In some use cases, the locking dogs are about seven feet above ground level making it difficult for the operator to produce enough force to disengage the locking dog while reaching overhead. In other use cases, the locking dogs are <NUM> feet or more above ground level, and the operator must stand on an elevated surface or use an extended tool to reach and disengage them. The locking dogs may also be positioned at or near ground level, which is also an awkward position in which to disengage the locking dogs.

Furthermore, significant load can be present between the locking dogs and the drive wrench and/or anchor/pile retained by the locking dogs. Binding due to this load can make it very difficult to pull out the dogs, and damage to the locking dog operating rings is common when leverage is required to pull out the locking dogs. <CIT> discloses a body including inner cavity with a lower opening, first cylindrical cavity on a first side of the body, and a second cylindrical cavity on a second side of the body opposite the first side, a first locking dog in the first cylindrical cavity at least partially extending through the first side of the body and displaceable into and out of the inner cavity, a second locking dog in the second cylindrical cavity at least partially extending through the second side of the body, and displaceable into and out of the inner cavity, a mechanism for simultaneous displacement of the first and second locking dogs with mechanical advantage.

Thus, there is a need for improved locking dog assemblies that are easier to operate and not prone to hazardous failures. The present invention solves these and other problems in the prior art.

An object of the present invention is to provide a locking dog assembly with improved ergonomics for the locking dog operation. A further object is the provision of a feature to protect the locking dog springs from damage and reduce or eliminate the chance of a safety hazard from damaged springs. A further object is to provide mechanical advantage for actuating locking dogs, particularly when retracting the locking dogs when binding force is present. The features and locking dog assemblies described herein may be useful for installing helical anchors and piles, though the applications are not limited thereto.

In one exemplary embodiment, a locking dog assembly is provided with a mechanism enabling simultaneous operation of both locking dogs. In some exemplary embodiments, the locking dog assembly includes a feature such as a step within the cylinder wall acting as a stop for outward travel of the locking dog.

In accordance with the present invention, a locking dog assembly is provided having the features of claim <NUM>.

Optional, preferred features are defined in the dependent claims.

The step between the proximal and central portions of each housing when provided engages against the step between the distal and central portions of each locking dog when the locking dog is in a fully disengaged position. This interaction between the steps defines a stop limiting a range of movement of the respective locking dog and protecting the respective spring from being over-compressed.

The cam assembly and lever are just one example of the mechanism. One skilled in the art will understand from this disclosure that other mechanisms may be used for simultaneous operation, such as different cam mechanisms, a rack and pinion mechanism, a lead screw mechanism, a solenoid mechanism, a linkage and actuator mechanism, a crank and rod mechanism, a chain loop and sprocket mechanism, a drum and cable mechanism, a scissor mechanism, and/or a wedge mechanism. The mechanism may be hand actuated, or driven hydraulically, pneumatically, or via an electric motor or actuator.

A more complete appreciation of the present disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:.

The present disclosure may be understood more readily by reference to the following detailed description of the disclosure taken in connection with the accompanying drawing figures, which form a part of this disclosure. It is to be understood that this disclosure is not limited to the specific devices, methods, conditions, or parameters described and/or shown herein, and that the terminology used herein is for the purpose of describing particular embodiments by way of example only and is not intended to be limiting of the claimed disclosure.

Also, as used in the specification and including the appended claims, the singular forms "a," "an," and "the" include the plural, and reference to a particular numerical value includes at least that particular value, unless the context clearly dictates otherwise. Ranges may be expressed herein as from "about" or "approximately" one particular value and/or to "about" or "approximately" another particular value. Similarly, when values are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another embodiment. It is also understood that all spatial references, such as, for example, horizontal, vertical, top, upper, lower, bottom, left and right, are for illustrative purposes only and can be varied within the scope of the disclosure.

<FIG> shows a locking dog assembly <NUM> according to an exemplary embodiment of the present disclosure. The assembly <NUM> includes a tool body or body <NUM> with an inner cavity <NUM> having upper and/or lower openings. The assembly <NUM> further includes an upper flange <NUM> about the upper opening for attaching to and/or receiving a rotational force from a driver. In some embodiments, a torque indicator is secured to the upper flange <NUM>. The torque indicator is then secured, directly or indirectly, to the driver.

As shown in <FIG> and <FIG>, the tool body <NUM> includes orifices 116a,116b opening into the inner cavity <NUM> of the tool body <NUM>. In the exemplary embodiment, the orifices 116a,116b are cylindrical cavities formed integrally with the body <NUM>. The orifices 116a and 116b receive locking dogs 120a and 120b, respectively. In the exemplary embodiment, the locking dogs 120a,120b are positioned opposite to one another and translate into and out of the inner cavity <NUM> along a same locking dog axis. In other embodiments, the locking dogs 120a,120b may translate along different axes. As discussed in more detail below, the locking dogs 120a,120b may be biased with springs toward an engaged position into the inner cavity <NUM>.

Each locking dog 120a,120b may be positioned within a respective locking dog housing 122a,122b. In the exemplary embodiment, the locking dog housings 122a and 112b are cylindrical and retained within the orifices 116a and 116b, respectively, via dowel pins <NUM> (see <FIG>). Each dowel pin <NUM> extends at least partially into a hole in a side surface of a respective orifice 116a,116b and to engage a complementary surface <NUM> (see <FIG>) on an exterior of a respective locking dog housing 122a and 122b and prevent axial and rotational movement of the locking dog housing 122a,122b. Cotter pins <NUM> may secure the dowel pins <NUM> in place. In some embodiments, the locking dog housings 122a,122b are integral to the tool body <NUM>. The dowel pin retention of the locking dog housings disclosed in this application may be applied to many other tools having locking dogs or other similar elements and is not limited to use with the tools disclosed herein.

In the exemplary embodiment, the locking dog assembly <NUM> includes a rotatable lever <NUM> which may be actuated by hand or with a tool to simultaneously move the locking dogs 120a,120b outward toward their disengaged positions at least partially outside of the inner cavity <NUM> and back inward to their engaged positions. The lever <NUM> can advantageously be operated with one hand. <FIG> illustrates one exemplary embodiment of a lever <NUM> that is removably secured (e.g., using a nut and cotter pin) about a spindle <NUM> defining an axis. The lever <NUM> has a handle portion <NUM>. In some embodiments, the locking dog assembly <NUM> is actuated hydraulically, pneumatically, and/or electrically with a motor or actuator.

As shown in <FIG>, a cover <NUM> may be provided to conceal and protect, and/or protect users from, internal components of the locking dog assembly <NUM> as discussed in more detail below. <FIG> illustrates the locking dog assembly <NUM> with the cover <NUM> removed.

The locking dog assembly <NUM> includes a mechanism for simultaneous activation of the first and second locking dogs. The mechanism may be, but is not limited to, a cam assembly <NUM> rotatable about the spindle <NUM> defining a cam axis as shown in <FIG>. The cam assembly <NUM> is actuated via the lever <NUM> to selectively displace each of the first and second locking dogs 120a,120b. First and second locking dog extensions 150a and 150b are coupled to the mechanism which, in this example, is the cam assembly <NUM>. The first and second locking dog extensions 150a and 150b are adjacent to the cam assembly <NUM> and pressed against the cam assembly <NUM> via spring forces in the first and second locking dogs 120a,120b. In the exemplary embodiment, the cam assembly <NUM> acts simultaneously on first and second locking dog extensions 150a and 150b which in turn acts on the locking dogs 120a and 120b, respectively.

<FIG> is a front view of the locking dog assembly <NUM> with the cover <NUM> and <FIG> is a front view of the locking dog assembly <NUM> with the cover <NUM> and lever <NUM> removed. As shown in <FIG>, the first and second locking dog extensions 150a,150b extend into the locking dog assembly <NUM> and are slidably retained in respective guide slots <NUM> and <NUM>. The cam assembly <NUM> may include a first cam <NUM> and a second cam <NUM>. In the exemplary embodiment, the first cam <NUM> is positioned outboard on the spindle <NUM> and interacts with the first locking dog extension 150a. The second cam <NUM> is positioned inboard on the spindle <NUM> and interacts with the second locking dog extension 150b.

In <FIG> and <FIG>, the cam assembly <NUM> is shown in a rest or engaged position whereby the locking dogs 120a,120b are engaged in the inner cavity <NUM>. In the exemplary embodiment, the locking dogs 120a,120b are biased inward toward their engaged positions by springs. The first and second cams <NUM>,<NUM> may each include multiple cam surfaces or positions to enable selective positioning of the locking dogs 120a,120b. In some embodiments, there are two positions. In the exemplary embodiment, there are three positions including the engaged (inward) position, an intermediate position, and a disengaged (outward) position.

<FIG> illustrate how the cam assembly <NUM> may rotate (e.g., by means of the lever <NUM>) to disengage the locking dogs 120a,120b. <FIG> shows the cam assembly <NUM> in the intermediate position having been rotated (e.g., clockwise) and having pushed the locking dogs 120a,120b outward (e.g., against springs) to partially disengage them from the inner cavity <NUM>. The cam assembly <NUM> includes a surface which provides a secure detent at the intermediate position. Continuing to rotate the cam assembly <NUM> further moves the locking dogs 120a,120b outward. <FIG> shows the cam assembly <NUM> rotated further to the disengaged position such that the locking dogs 120a,120b are pushed fully (or almost fully) outward from the inner cavity <NUM>.

As shown in <FIG>, the cams <NUM>,<NUM> may have flat distal surfaces which contact the locking dog extensions 150a,150b in the disengaged position. This provides a secure detent at the disengaged position. To reengage the locking dogs 120a,120b, the operator may rotate the lever <NUM> against the spring resistance far enough that the cams <NUM>,<NUM> are beyond the position where the locking dogs 120a,120b are at their maximum outward position. After this point, the spring force pushes the dogs 120a,120b in and rotates the cams <NUM>,<NUM> and lever <NUM> automatically to the engaged position. The length of the lever <NUM> and cam-actuated disengagement of the locking dogs 120a,120b provide the operator with mechanical advantage to overcome binding force on the locking dogs 120a,120b.

<FIG> and <FIG> are bottom views of the locking dog assembly <NUM>. In <FIG>, the lever <NUM> is in an engaged position and the locking dogs 120a,120b are engaged (as if bearing against an inserted anchor assembly). Proximal ends 124a and 124b of the locking dogs 120a and 120b, respectively, are extended into the inner cavity <NUM> to retain an anchor and/or drive wrench in the inner cavity <NUM>. In <FIG>, the lever <NUM> is rotated such that the locking dogs 120a,120b are fully (or close to fully) disengaged. Proximal ends 124a and 124b of the locking dogs 120a and 120b, respectively, are retracted from the inner cavity <NUM> to release an anchor and/or drive wrench from the inner cavity <NUM>.

<FIG> shows the cam assembly <NUM> and locking dogs 120a,120b of the locking dog assembly <NUM>. For purposes of illustration, the first locking dog 120a is shown without its housing 122a and the second locking dog 120b is shown in its housing 122b. Each locking dog 122a,122b has a proximal end or surface 124a,124b, a central portion 126a,126b, and a distal portion 128a,128b. The central portion 126a,126b has a greater diameter than the distal portion 128a,128b and/or the proximal end 124a,124b. The first and second locking dog extensions 150a,150b extend through slots on the exterior of the respective housings 122a,122a and connect to the respective locking dogs 120a,120b. In the exemplary embodiment, the locking dog extensions 150a,150b extend into the central portions 126a,126b of the locking dogs 120a,120b.

<FIG> is a rear sectional view of the cam assembly <NUM> and locking dogs 120a,120b. Each locking dog 120a,120b is retained within its respective locking dog housing 122a,122b together with a spring 160a,160b (see also <FIG>). The locking dog housings 122a,122b each have a proximal cavity 162a,162b, a central cavity 166a,166b, with a step 164a,164b between the proximal cavity 162a,162b and the central cavity 166a,166b, and a distal cavity (or aperture) 168a,168b. The spring 160a,160b acts between a distal wall of the central cavity 166a,166b and a distal surface of the central portion 126a,126b of the locking dog 120a,120b.

The step 164a,164b functions as a solid locking dog stop to establish an outward limit for the travel of the locking dog 120a,120b when disengaging. In particular, the central cavity 166a,166b of the locking dog housing 122a,122b may have a length that is greater than a length of the spring 160a,160b when fully compressed. This arrangement advantageously protects the spring 160a,160b from being over-compressed and damaged, such as if a backlash were to occur. The locking dog stop disclosed in this application may be applied to many other tools having locking dogs or other similar elements and is not limited to use with the tools disclosed herein.

As shown in <FIG>, the locking dog extensions 150a,150b may extend into receptacles or channels in the respective locking dogs 120a,120b. In the exemplary embodiment, distal ends of the locking dog extensions 150a,150b are retained in the locking dogs 120a,120b with a first set screw, a spacer, a second set screw, and a spring pin.

<FIG> is an isometric view of a locking dog assembly <NUM> according to an exemplary embodiment of the present disclosure. In the exemplary embodiment, the cover is removed or not provided. The locking dog assembly <NUM> has a smaller inner cavity <NUM> with smaller upper and/or lower openings to accommodate different applications. The locking dog assembly <NUM> also has a different cam assembly <NUM>, though it may also be employed in the previous embodiment. The cam assembly <NUM> includes cams <NUM>,<NUM> shaped such that there is no intermediate position as may be desired for certain applications. Other mechanisms may also be used as described herein.

<FIG> and <FIG> illustrate how the cam assembly <NUM> rotates to disengage the locking dogs 220a,220b. <FIG> shows the cam assembly <NUM> being rotated (e.g., clockwise) from an engaged position. <FIG> shows the cam assembly <NUM> rotated further to the disengaged position such that the locking dogs 220a,220b are pushed fully (or almost fully) outward from the inner cavity <NUM>. As shown in <FIG>, the cams <NUM>,<NUM> have flat distal surfaces which contact the locking dog extensions 250a,250b in the disengaged position. As in the previous embodiment, this provides a secure detent at the disengaged position.

<FIG> is an isometric view of a locking dog assembly <NUM> according to an exemplary embodiment of the present disclosure. The assembly <NUM> includes a tool body or body <NUM> with an inner cavity <NUM> having upper and/or lower openings. Unlike the body <NUM> shown in <FIG>, the body <NUM> includes an extended upper portion <NUM> including an integrated hex socket for attaching to a driver.

<FIG> is an isometric view of another locking dog assembly <NUM> according to an exemplary embodiment of the present disclosure with locking dogs 420a,420b in an engaged position. <FIG> is an isometric view of the locking dog assembly <NUM> with the locking dogs 420a,420b in a disengaged position. In this embodiment, the lever includes left and right lever components 432a,432b that are actuated up and down simultaneously via a connected handle <NUM> (e.g., with one hand) to disengage and engage the locking dogs 420a,420b. Locking dog extensions 450a,450b extend radially from the locking dogs 420a,420b, through slots in the orifices 416a,416b, and slide along ramps on cam portions of the lever components 432a,432b. Each locking dog extension 450a,450b may be a single piece extending through a respective locking dog, or two separate pieces with one piece attached to or formed integrally on each side of the respective locking dog. Each ramp may include a rest or full engagement position, an intermediate step for partial disengagement, and a final step (shown in <FIG>) for full disengagement.

<FIG> and <FIG> are bottom views of the locking dog assembly <NUM>. In <FIG>, the lever 432a,432b is shown in a rest position and the locking dogs 420a and 420b are engaged (as if bearing against an inserted anchor assembly). Proximal ends 424a and 424b of the locking dogs 420a and 420b, respectively, are extended into the inner cavity <NUM> to retain an anchor and/or drive wrench in the inner cavity <NUM>. In <FIG>, the lever 432a,432b is rotated such that the locking dogs 420a,420b are fully (or close to fully) disengaged. Proximal ends 424a and 424b of the locking dogs 420a and 420b, respectively, are retracted from the inner cavity <NUM> to release an anchor and/or drive wrench from the inner cavity <NUM>.

<FIG> is an isometric view of the lever 432a,432b and internal components of the locking dog assembly <NUM> shown in <FIG> and <FIG>. Each lever component 432a,432b has a cam portion at its proximal end rotating about a cam axis. The cam axis may be the same axis along which the locking dogs 420a,420b translate into and out of the inner cavity <NUM>. The locking dog extensions 450a,450b, which in this case are cylindrical members, extend through respective slots in the tops of the locking dog housings 422a,422b, through central portions of the locking dogs 420a and 420b, and out of respective slots in the bottoms of the locking dog housings 422a,422b. The locking dogs 420a,420b are biased inward using springs 460a,460b.

The locking dog housings 422a,422b may be retained in the orifices 416a,416b via dowel pins <NUM>. Each dowel pin <NUM> engages a complementary surface on an exterior of a respective locking dog housing 422a,422b and prevents axial and rotational movement of the locking dog housing 422a,422b. Cotter pins <NUM>, positioned above the dowel pins <NUM>, may secure the dowel pins <NUM> in place.

<FIG> is an isometric view of the lever component 432b of the locking dog assembly <NUM> shown in <FIG> and <FIG>. Each lever component 432a,432b has a cam portion including ramps to engage the locking dog extensions 450a,450b. As shown in <FIG>, the cam portion of the lever component 432b has two complementary ramps (e.g., each with two or three positions) whereby ramp 436b engages a top of the locking dog extension 450b and the ramp 438b engages a bottom of the locking dog extension 450b. The ramps 436a,436b and 438a,438b have intermediate detents and outer detents to retain the locking dog extension 450b at positions defined by such detents. Lever component 432a has a similar, albeit opposite, construction.

<FIG> is an isometric view of a locking dog assembly <NUM> according to an exemplary embodiment of the present disclosure. The assembly <NUM> includes a tool body or body <NUM> with an inner cavity <NUM> having upper and/or lower openings. The structure and features of the locking dog assembly <NUM> may be similar to the other examples described herein. However, in this example, the mechanism is a hydraulic mechanism including a hydraulic actuator <NUM> and a hydraulic fluid reservoir <NUM>. The hydraulic actuator <NUM> is double sided including piston rods 543a,543b acting on locking dog extensions 550a,550b. The hydraulic mechanism is actuated using a pump and lever assembly <NUM>. If only two locking dog positions are needed (engaged and retracted), the pump and cylinder of the actuator can be single chambers. If multiple positions are needed (including an intermediate position), the locking dog motion should be synchronized and therefore the pump and cylinder of the actuator should have dual chambers (operating in parallel). The hydraulic mechanism may alternatively have a single sided hydraulic actuator <NUM> with a piston rod <NUM> as shown in <FIG>. The hydraulic mechanism may also include a scissor mechanism <NUM> acting between and guiding locking dog extensions 1150a,1150b as shown in <FIG>. A pump and lever assembly may also be included in the embodiment shown in <FIG>. The actuator <NUM> shown in <FIG> can alternatively be a pneumatic actuator or an electric actuator.

<FIG> is an isometric view of a locking dog assembly <NUM> according to an exemplary embodiment of the present disclosure. The assembly <NUM> includes a tool body or body <NUM> with an inner cavity <NUM> having upper and/or lower openings. The structure and features of the locking dog assembly <NUM> may be similar to the other examples described herein. However, in this example, the mechanism is a lead screw mechanism including screws 643a,643b. Each screw 643a,643b has a bevel gear 645a,645b at its proximal end and is threaded through a locking dog extension 650a,650b at its distal end. A lever <NUM> is provided and connected to an actuating bevel gear meshed with and driving the two bevel gears 645a,645b. The lead screw mechanism and in turn the screws 643a,643b are actuated using the lever <NUM>. Rotation of the screws 643a,643b through the respective locking dog extensions 650a,650b moves the locking dog extensions 650a,650b. Alternatively, the lever <NUM> may be connected to a conical head rather than an actuating bevel gear and the screws 643a,643b may be replaced with unthreaded rods. Rotation of the lever <NUM> causes the conical head to translate towards the body <NUM> and act against circular followers on each unthreaded rod, thereby moving the locking dogs 620a,620b in a linear fashion.

<FIG> is an isometric view of a locking dog assembly <NUM> according to an exemplary embodiment of the present disclosure. The assembly <NUM> includes a tool body or body <NUM> with an inner cavity <NUM> having upper and/or lower openings. The structure and features of the locking dog assembly <NUM> may be similar to the other examples described herein. Similar to the example shown in <FIG>, the mechanism is a lead screw mechanism including screws 743a,743b. In this example, the lead screw mechanism is motorized using a motor <NUM> in communication with a control assembly <NUM>, e.g., including a battery and electronics. The motor <NUM> drives an actuating bevel gear meshed with and driving the bevel gears on the proximal ends of the screws 743a,743b. The motor <NUM> may be, for example, an electric motor. Though the motor <NUM> is shown with a lead screw mechanism, the motor <NUM> can be used with any of the mechanisms described herein. As shown in <FIG>, the lead screw mechanism can alternatively be arranged with a single screw <NUM> having a spur gear <NUM>. In this embodiment, the spur gear <NUM> is driven by a motor <NUM> via another spur gear <NUM>. A control assembly <NUM>, e.g., including a battery and electronics, is in communication with the motor <NUM>.

<FIG> is an isometric view of a locking dog assembly <NUM> according to an exemplary embodiment of the present disclosure. The assembly <NUM> includes a tool body or body <NUM> with an inner cavity <NUM> having upper and/or lower openings. The structure and features of the locking dog assembly <NUM> may be similar to the other examples described herein. However, in this example, the mechanism is a rack and pinion mechanism. The mechanism includes a pinion <NUM> secured about a spindle <NUM> rotatable by means of a lever <NUM>. In other embodiments, the pinion <NUM> is rotatable with a motor. The pinion <NUM> engages with racks 843a,843b secured to locking dog extensions 850a,850b, respectively. Rotation of the pinion <NUM> (e.g., clockwise) causes the racks 843a,843b to move outward which in turn moves the locking dog extensions 850a,850b and locking dogs 820a,820b outward.

In some embodiments, the locking dog assembly <NUM> includes a retention feature to hold the locking dogs 820a,820b in the intermediate (if included) and retracted (outward) positions. For example, the retention feature may include a drum, pin, and plunger mechanism. In some embodiments, the mechanism includes a cylindrical drum <NUM> coaxial with and integral with or attached to the pinion <NUM> as shown in <FIG>. In the exemplary embodiment, the drum <NUM> has a stepped track <NUM> cut therethrough with steps corresponding to angular positions of the drum <NUM> when the locking dogs 820a,820b are in the retracted position(s). In the exemplary embodiment, the stepped track <NUM> includes a first step <NUM> (e.g., at the fully retracted position), a second step <NUM> (e.g., at an intermediate position), and a fully engaged portion <NUM>. The retention feature includes a locking pin <NUM> extending through the stepped track <NUM>, a tool body spindle <NUM>, and a plunger <NUM>. The locking pin <NUM> may be oriented perpendicular to a rotational axis of the drum <NUM>. The plunger <NUM> may be a spring-loaded plunger coaxial with the drum <NUM> and moving axially inside the tool body spindle <NUM>. The spring pushes the locking pin <NUM> into the steps in the stepped track <NUM> as it rotates (e.g., clockwise). This prevents rotation in the opposite direction past the step until the plunger <NUM> is pushed in against the spring and the locking pin <NUM> is disengaged from the step. In other embodiments, the mechanism includes a spring catch or catches mounted on the tool body that push down under the handle as it rotates past (e.g., clockwise) and engage behind the handle after it passes. Catches are located to correspond with the locking dog intermediate (if included) and retracted positions. The catch is depressed to allow the handle to rotate back (e.g., counterclockwise).

<FIG> is an isometric view of a locking dog assembly <NUM> according to an exemplary embodiment of the present disclosure. <FIG> is a front view of the locking dog assembly <NUM> with a lever <NUM> removed for clarity. The assembly <NUM> includes a tool body or body <NUM> with an inner cavity <NUM> having upper and/or lower openings. The structure and features of the locking dog assembly <NUM> may be similar to the other examples described herein. However, in this example, the mechanism is a crank and rod mechanism. The mechanism includes the lever <NUM> actuating a crank <NUM> secured about a spindle <NUM>. In other embodiments, the crank <NUM> is rotatable with a motor. A first rod 943a is rotatably secured between the crank <NUM> and a first locking dog extension 950a. A second rod 943b is rotatably secured between the crank <NUM> and a second locking dog extension 950b. Rotation of the crank <NUM> (e.g., clockwise) causes the rods 943a,943b to move the locking dog extensions 950a,950b and the locking dogs 920a,920b outward. In some embodiments, the locking dog assembly <NUM> includes a retention feature (e.g., as discussed above) interfacing with the crank <NUM> or lever <NUM> to hold the locking dogs 920a,920b in the intermediate (if included) and retracted (outward) positions.

<FIG> is an isometric view of a locking dog assembly <NUM> according to an exemplary embodiment of the present disclosure. The assembly <NUM> includes a tool body or body <NUM> with an inner cavity <NUM> having upper and/or lower openings. The structure and features of the locking dog assembly <NUM> may be similar to the other examples described herein. However, in this example, the mechanism is a sliding cam <NUM>. The sliding cam <NUM> is slidably secured between two channels on an exterior of the body <NUM>. The sliding cam <NUM> is actuated up and down using a handle <NUM>. The sliding cam <NUM> includes two or more sets of corresponding detents or notches positioned at different widths on each side to receive locking dog extensions 1050a,1050b and position the locking dogs 1020a,1020b.

<FIG> shows a locking dog assembly <NUM> according to an exemplary embodiment of the present disclosure. Similar to the locking dog assembly <NUM> shown in <FIG>, the assembly <NUM> includes a tool body <NUM> with an inner cavity <NUM> and an upper flange <NUM>. The tool body <NUM> includes orifices 1416a,1416b, opening into the inner cavity <NUM>, configured to receive locking dogs 1420a and 1420b, respectively. The locking dogs 1420a,1420b may be biased with springs toward an engaged position into the inner cavity <NUM> (see, e.g., <FIG>).

The locking dog assembly <NUM> includes a rotatable lever <NUM> which may be actuated by hand or with a tool to simultaneously move the locking dogs 1420a,1420b outward toward their disengaged positions at least partially outside of the inner cavity <NUM> and back inward to their engaged positions. The lever <NUM> is removably secured about a spindle <NUM> defining an axis. The lever <NUM> has a handle portion <NUM>.

As shown in <FIG>, the mechanism for simultaneous activation of the first and second locking dogs includes a cam assembly <NUM> rotatable about the spindle <NUM> and actuated via the lever <NUM>. The cam <NUM> is comprised of an oval shaped component with two closed tracks for receiving and actuating first and second locking dog extensions 1450a and 1450b. The tracks may include detent locations for intermediate and/or fully disengaged positions (e.g., as described above with respect to <FIG>, <FIG>, <FIG>, and/or <FIG>) or may include a retention feature as discussed above (e.g., para. <NUM> and <NUM>) and as shown in <FIG>.

<FIG> is an isometric view of another locking dog assembly <NUM> according to an exemplary embodiment of the present disclosure. Similar to the locking dog assembly <NUM> shown in <FIG>, the locking dog assembly <NUM> includes locking dogs 1520a,1520b actuated by a lever with left and right lever components 1532a,1532b that are actuated up and down simultaneously via a connected handle <NUM>.

The locking dog assembly <NUM> includes locking dogs 1520a,1520b that may be positioned within or formed integrally with locking dog housings 1522a,1522b. Each lever component 1532a,1532b has a base 1536a,1536b circumscribing a respective one of the locking dog housings 1522a,1522b. An internal surface of each base 1536a,1536b is threaded and a corresponding exterior surface of each locking dog housing 1522a,1522b is threaded (not shown). The threads are opposite of one another on each side of the locking dog assembly <NUM> such that rotation of the lever causes each locking dog housing 1522a,1522b and/or locking dog 1520a,1520b to move inward and outward by rotation of the lever.

The mechanisms described above are only exemplary and are not intended to be limiting. Other means to simultaneously activate first and second locking dogs may also be used in place of or in combination. For example, the mechanism may be a cable loop mechanism including a cable looped around a central drum on the tool body and pulleys positioned near the ends of the locking dog housings. The central drum may be rotated (by hand or a motor) to drive the cable. The cable may be fastened to the locking dog extensions (e.g., between the central drum and pulleys) such that the locking dogs are pulled outward when the cable rotates. A mechanism to hold the locking dogs at the disengaged location(s) may interface with the central drum or an operating handle. Similarly, a chain loop mechanism may be used having a chain in place of the cable and sprockets in place of the central drum and pulleys.

Alternatively, the mechanism may include a central drum with two cables wrapped at least partially around the central drum. A distal end of each cable may be attached to and/or inside of a respective locking dog. When the central drum is rotated, the cables are tensioned to pull the locking dogs outward. In some embodiments, the locking dog shanks (distal sections) are slotted along their vertical center planes to provide channels for the cable housings when the dogs are pulled out. A mechanism to hold the locking dogs at the disengaged location(s) may interface with the central drum or operating handle.

In other embodiments, the linkage mechanism may include a scissor jack that pushes locking dogs outward out via locking dog extensions. The mechanism may be driven by a threaded rod (e.g., vertically disposed on the tool body) that pulls central pivots of the scissor jack together. One end of the threaded rod may be right-handed thread and the other end left-handed thread. The mechanism may alternatively be driven by a cable that pulls the central pivots of the scissor mechanism together. A mechanism to hold the locking dogs at the disengaged location(s) may interface with the cable or linkage.

In other embodiments, the mechanism may include one or more solenoids to push the locking dogs outward. This may be particularly useful for tools with only two locking dog positions (engaged and disengaged), but it is not limited thereto. The solenoids may be mounted externally on the tool body and push the locking dogs outward via locking dog extensions. Alternatively, the solenoids may be integrated with the locking dogs (e.g., such that the locking dog shank [distal section] is the solenoid stem) or may be attached coaxially with the locking dogs rather than acting on locking dog extensions.

Claim 1:
A locking dog assembly (<NUM>), comprising:
a body (<NUM>) including inner cavity (<NUM>) with a lower opening, a first cylindrical cavity (116a) on a first side of the body (<NUM>), and a second cylindrical cavity (116b) on a second side of the body (<NUM>) opposite the first side;
a first locking dog (120a) in the first cylindrical cavity (116a) at least partially extending through the first side of the body (<NUM>) and displaceable into and out of the inner cavity (<NUM>);
a second locking dog (120b) in the second cylindrical cavity (116b) at least partially extending through the second side of the body (<NUM>), and displaceable into and out of the inner cavity (<NUM>);
a mechanism (<NUM>) for simultaneous displacement of the first and second locking dogs (120a, 120b) with mechanical advantage; characterized by a first locking dog extension (150a) having a first end extending through a slot (<NUM>) in a curved side
of the first cylindrical cavity (116a) and connected to the first locking dog (120a) and a second end coupled to the mechanism (<NUM>), wherein the mechanism (<NUM>) displaces the first locking dog (120a) via the first locking dog extension (150a); and
a second locking dog extension (150b) having a first end extending through a slot (<NUM>) in a curved side
of the second cylindrical cavity (116b) and connected to the second locking dog (120b) and a second end coupled to the mechanism (<NUM>), wherein the mechanism (<NUM>) displaces the second locking dog (120b) via the second locking dog extension (150b).