Patent Description:
Once the hole is complete, a product such as cable, pipe, conduit, and the like is attached to the drill string and the drill string is pulled back through the hole to install the product in the hole. To pull the product through the hole, the rotary drill bit, or at least a portion thereof, is removed from the drill string to allow for the attachment of a pullback device that connects the product to the drill string. This process is time consuming and requires additional tooling to remove or partially remove the rotary drill bit to complete the pullback process. Therefore, improvements are needed.

<CIT> discloses an over-bit backreamer. <CIT> discloses direct pullback devices and a method of horizontal drilling. <CIT> discloses the use of coiled tubing unit systems in sub sea operations. <CIT> discloses a drill bit assembly for a directional percussion boring system.

The present disclosure relates generally to a rotary drill bit and a pullback device for a rotary drill bit used for horizontal directional drilling operations. In one possible configuration, and by non-limiting example, a pullback device is removably secured to the rotary drill bit without removing the drill bit, or any portion thereof, from the drill string.

In one aspect, the invention provides a rotary drill bit for use with a horizontal directional drill string. A coupler at a proximal axial end is configured to attach the rotary drill bit to a drill head at a distal end of the drill string. A cutting portion at a distal axial end is provided with a plurality of vanes with respective cutters that operate to cut a hole in earth when the rotary drill bit is rotated about a central axis. The plurality of vanes project radially outwardly from a surface of the cutting portion such that the surface forms respective troughs circumferentially interspersed with the plurality of vanes. A plurality of engagement features are positioned axially within the cutting portion and radially inward of an outer cutting diameter to facilitate attachment of a product pullback device between the plurality of vanes without removing the rotary drill bit, or any portion thereof, from the drill head.

In another aspect, the invention provides a method including operating a horizontal directional drilling machine to thrust a drill string having a rotary drill bit into the earth to drill an underground hole from a start location to an end location, the rotary drill bit having a cutting portion defined by a plurality of vanes projecting radially outward from a surface to define an outer cutting diameter. At the end location, a pullback device is attached to a plurality of engagement features of the rotary drill bit at respective positions along a surface of the rotary drill bit that is axially within the cutting portion and radially inward of an outer cutting diameter. A product is attached to an attachment portion of the pullback device at the end location. The drill string, including the rotary drill bit, the pullback device, and the product, is pulled back through the underground hole from the end location to the start location to install the product into the underground hole. The product is detached from the pullback device at the start location.

One aspect relates to a pullback device for attaching to a rotary drill bit without disassembling or removing the rotary drill bit from a drill string. The pullback device comprises: a frame member; a collar configured to attach the pullback device to the rotary drill bit; and arms each having a first end slidably engaged with the frame member and a second end slidably engaged with the collar.

Another aspect relates to a pullback system for installing product in a hole. The system comprises: a rotary drill bit having a plurality of vanes with cutters and a base, the base being located between the plurality of vanes and a coupler, the coupler being configured to attach the rotary drill bit to a drill head; and a pullback device that attaches to the rotary drill bit without disassembling or removing the rotary drill bit from the drill head, the pullback device including: a frame member; a collar that attaches the pullback device to the rotary drill bit; a plurality of arms each having a first end slidably engaged with the frame member and a second end slidably engaged with the collar; and at least one attachment location configured to attach the product to the pullback device.

Another aspect relates to a method of installing product in a hole, the method comprising: using a rotary drill bit having a plurality of vanes with cutters to drill a hole from a start location to an end location; attaching a pullback device to a base of the rotary drill bit at the end location; attaching a product to the pullback device at the end location; pulling back the rotary drill bit from the end location to the start location, and detaching the product from the pullback device at the start location.

Another aspect relates to a pullback device for attaching to a rotary drill bit without disassembling or removing the rotary drill bit from a drill string. The pullback device comprises: a product attachment portion configured to align with a central axis of the rotary drill bit and to attach product to the pullback device; and an anchoring portion for securing the product attachment portion to the rotary drill bit. The anchoring portion engages a base of the rotary drill bit to attach the pullback device to the rotary drill bit.

Another aspect relates to a method of pulling back product in a hole drilled by a rotary drill bit coupled to a drill string. The rotary drill bit has a base defining a central axis about which the rotary drill bit rotates during drilling and a plurality of vanes extending from the base. Each vane has a plurality of cutters. The method comprises: attaching an anchoring portion of a pullback device to the base; attaching product to a product attachment portion of the pullback device; and pulling back the product through the hole by transferring a pullback load through the anchoring portion to the base.

A variety of additional aspects will be set forth in the description that follows. The aspects can relate to individual features and to combinations of features. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad inventive concepts upon which the embodiments disclosed herein are based.

The following drawings are illustrative of particular embodiments of the present disclosure and therefore do not limit the scope of the present disclosure. The drawings are not to scale and are intended for use in conjunction with the explanations in the following detailed description. Embodiments of the present disclosure will hereinafter be described in conjunction with the appended drawings, wherein like numerals denote like elements.

It is to be noted that the subject-matter as shown in and described here with respect to <FIG> is not part of the present invention.

The present disclosure pertains to a pullback device for installing product in a hole. The pullback device is attachable to a rotary drill bit without disassembling or removing the rotary drill bit from a drill string. The pullback device does not require specialized tools for attachment with the rotary drill bit, and thereby allows the pullback device to be easily attached to the rotary drill bit. The pullback system may include similar concepts described in <CIT>, assigned to VERMEER MANUFACTURING COMPANY.

<FIG> is a side view of a pullback system <NUM>. The pullback system <NUM> includes a pullback device <NUM> attached to rotary drill bit <NUM>. The rotary drill bit <NUM> is used for horizontal directional drilling operations, and is described in more detail with reference to <FIG>. The rotary drill bit <NUM> is attached to a distal end of a drill head <NUM>.

The drill head <NUM> includes a downhole end <NUM> and an up-hole end <NUM>. As shown in <FIG>, the rotary drill bit <NUM> is attached at the downhole end <NUM>. The drill head <NUM> is connectable at the up-hole end <NUM> to outer drill rods and inner drill rods of a drill string.

The drill head <NUM> includes a drill rod axis DR that has a bend at boundary <NUM>. In certain examples, the bend of the drill rod axis DR is about <NUM> degrees.

The drill head <NUM> is constructed to withstand large pullback forces during a pullback operation. In certain examples, the pullback device <NUM> is designed to fail or yield before damaging the drill head <NUM> during a pullback operation.

<FIG> is an isometric view of the pullback device <NUM> attached to the rotary drill bit <NUM>. The pullback device <NUM> is designed to attach to the rotary drill bit <NUM> without disassembling or removing the rotary drill bit <NUM> from the drill string. The pullback device <NUM> is also designed to attach to a base <NUM> of the rotary drill bit <NUM>, and to transfer a pullback force to the base <NUM> during a pullback operation.

<FIG> are isometric views, <FIG> is a side view, <FIG> is a front view, and <FIG> is a rear view of the rotary drill bit <NUM>. The rotary drill bit <NUM> includes a base <NUM>, a plurality of vanes <NUM>, and a coupler <NUM>. As shown, the base <NUM> is located between the plurality of vanes <NUM> and the coupler <NUM>.

The rotary drill bit <NUM> can be used on various drill rod drilling systems. In one example embodiment, the rotary drill bit <NUM> is used on a dual drill rod drilling system. Dual drill rod drilling systems are used for directional drilling, and are generally configured to drive into the ground a series of drill rods joined end-to-end to form a drill string. The rotary drill bit <NUM> is attached at a downhole end of the drill string. A dual drill rod drilling system is described in more detail in <CIT>.

The coupler <NUM> is used to attach the rotary drill bit <NUM> to the drill head <NUM> (see <FIG>) of the drill string. The coupler <NUM> includes threads <NUM> that mate with corresponding threads on the drill head <NUM> to attach the rotary drill bit <NUM> to the drill head <NUM>. As described above, the drill head <NUM> transfers torque and thrust from a drive mechanism to rotate the rotary drill bit <NUM> about a central axis RDB and to thrust the rotary drill bit <NUM> in a forward direction causing the plurality of vanes <NUM> to remove debris (e.g., rock, dirt, mud etc.) during a drilling operation.

The plurality of vanes <NUM> define a cutting portion of the rotary drill bit <NUM> and project radially outwardly from a surface that forms respective troughs <NUM> circumferentially interspersed with the plurality of vanes <NUM>. The plurality of vanes <NUM> can project radially outward (as shown in the end view of <FIG>), regardless of whether or not they also incorporate a tilt angle(s) or complex curvature. Each vane <NUM> includes a plurality of cutters <NUM>. In certain examples, the cutters <NUM> on the plurality of vanes <NUM> are polycrystalline diamond (PDC) compact cutters. In the depicted example, the rotary drill bit <NUM> has five vanes <NUM> separated by five troughs <NUM>. It is contemplated that the rotary drill bit <NUM> may have a variety of configurations including a variety of quantities, shapes, and placements of the vanes <NUM>, troughs <NUM>, and cutters <NUM>.

In certain examples, the base <NUM> includes at least one anchor <NUM> that is engaged by an anchoring portion of the pullback device <NUM> to secure the pullback device <NUM> to the base <NUM> of the rotary drill bit <NUM>. In such examples, the at least one anchor <NUM> can be used to install the rotary drill bit <NUM> to the drill head <NUM> such as by providing one or more surfaces for a wrench or similar tool to latch onto to thread and torque the rotary drill bit <NUM> onto the drill head <NUM>. The at least one anchor <NUM> on the rotary drill bit <NUM> is robust and able to withstand loads during pullback operations. In alternative examples, the base <NUM> does not include an anchor <NUM>, and the anchoring portion of the pullback device <NUM> is secured to the base <NUM> without having to engage an anchor <NUM>.

In the depicted example, the base includes two anchors <NUM> on opposite sides of the central axis RDB of the rotary drill bit <NUM>. The examples depicted in the figures, the anchors <NUM> are cut out portions of the base <NUM> and include surfaces <NUM>, <NUM> that are flat and orthogonal to the central axis RDB of the rotary drill bit <NUM> (see <FIG>). The pullback device <NUM> is configured to engage at least one surface <NUM>, <NUM> of each anchor <NUM> to transfer a pullback force to the base <NUM> during a pullback operation.

The anchors <NUM> may have a variety of configurations, shapes, and placements on the base <NUM>. For example, the base <NUM> may include a single anchor <NUM>, may include more than two anchors <NUM>, or may not include an anchor <NUM>. In one example, the base <NUM> may include a single anchor <NUM> such as a groove that wraps around the base <NUM>.

<FIG> are isometric views of the pullback device <NUM>. <FIG> are side views of the pullback device <NUM>. As shown in these figures, the pullback device <NUM> includes a frame member <NUM>, a collar <NUM>, and a plurality of arms <NUM>.

The frame member <NUM> has at least one attachment location <NUM>. The attachment locations <NUM> can be used to attach product to the pullback device <NUM>. In certain examples, the frame member <NUM> and the at least one attachment location <NUM> are part of a product attachment portion of the pullback device <NUM> that aligns with the central axis RDB of the rotary drill bit <NUM> and is used to attach product to the pullback device <NUM>.

In the examples depicted in the figures, the attachment location <NUM> is an aperture to which product can be directly or indirectly attached. It is contemplated that the frame member <NUM> may have a variety of configurations including more than one attachment location <NUM>. Additionally, it is contemplated that the attachment location <NUM> may have a variety of shapes and placements on the frame member <NUM>.

In certain examples, the collar <NUM> and the plurality of arms <NUM> are part of an anchoring portion of the pullback device <NUM> that secures the product attachment portion to the rotary drill bit <NUM> by engaging the base <NUM> of the rotary drill bit <NUM>. In certain examples, the collar <NUM> engages the at least one anchor <NUM> on the base <NUM> to secure the pullback device <NUM> to the rotary drill bit <NUM>. In such examples, the collar <NUM> transfers a pullback force to the base <NUM> through the at least one anchor <NUM> during a pullback operation. For example, as shown in the example depicted in <FIG>, the collar <NUM> is configured to fit between the orthogonal surfaces <NUM>, <NUM> such that during a pullback operation, the collar <NUM> engages at least one of the orthogonal surfaces <NUM>, <NUM> and transfers a pullback force to the base <NUM> through the orthogonal surfaces <NUM>, <NUM>.

In alternative examples where the base <NUM> does not include the at least one anchor <NUM>, the anchoring portion of the pullback device <NUM> can tightly clamp onto the exterior face of the base <NUM>. In some examples, the anchoring portion of the pullback device <NUM> can grab onto the back of the vanes <NUM>. In such examples, the anchoring portion can be configured as a grapple having pivoting arms that can grab onto the vanes <NUM> such as in the pullback device described in <CIT>.

<FIG> are top and bottom views, respectively, of the pullback device <NUM>. <FIG> are exploded views of the pullback device <NUM>. Referring now to <FIG>, each arm <NUM> has a first end <NUM> slidably engaged with the frame member <NUM> and a second end <NUM> slidably engaged with the collar <NUM>. The arms <NUM> are slidable about the frame member <NUM> and the collar <NUM> such that the arms <NUM> can rotate about a central axis PBD of the pullback device <NUM> (see <FIG>). When the pullback device <NUM> is attached to the rotary drill bit <NUM> such as shown in <FIG>, the central axis PBD of the pullback device <NUM> and the central axis RDB of the rotary drill bit <NUM> are coincident with one another, and accordingly, the arms <NUM> are also able to rotate about the central axis RDB of the rotary drill bit <NUM>. As provided herein, the plurality of arms <NUM> includes at least two arms <NUM>, three arms <NUM>, or more than three arms <NUM>.

<FIG> is an isometric view of an arm <NUM> of the pullback device <NUM>. As shown in <FIG>, the first end <NUM> includes a first surface <NUM>, a second surface <NUM>, a third surface <NUM>, and a fourth surface <NUM>. Referring now to <FIG>, and <FIG>, the first surface <NUM> is configured to slidably engage an exterior surface of the frame member <NUM>, the second surface <NUM> is configured to slidably engage a flange <NUM> that extends from the frame member <NUM>, the third surface <NUM> is configured to slidably engage an interior surface of a locking device <NUM>, and the fourth surface <NUM> is configured to engage a side surface of the locking device <NUM> orthogonal to the interior surface of the locking device <NUM>. The frame member <NUM>, flange <NUM>, and locking device <NUM> prevent axial and radial movement of the first end <NUM> with respect to the central axis PBD of the pullback device <NUM> while allowing the first end <NUM> to rotate about the central axis PBD.

As further shown in <FIG>, the second end <NUM> of the arm <NUM> includes a groove <NUM>. In certain examples, the groove <NUM> has a width that corresponds to a width of a glide portion <NUM> of the collar <NUM>. For example, the groove <NUM> may have a width that is equal to or greater than the width of the glide portion <NUM> of the collar <NUM>. Referring now to <FIG>, and <FIG>, the collar <NUM> prevents both axial and radial movement of the second ends <NUM> of the arms <NUM> with respect to the central axis PBD of the pullback device <NUM> while allowing the second ends <NUM> of the arms <NUM> to at least partially rotate about the central axis PBD of the pullback device <NUM> on the glide portion <NUM>.

Referring now to <FIG>, the pullback device <NUM> includes the locking device <NUM> that engages the frame member <NUM> and the first ends <NUM> of the arms <NUM>. The locking device <NUM> in combination with the flange <NUM> prevents axial and radial movement of the first ends <NUM> of the arms <NUM> with respect to the central axis PBD of the pullback device <NUM> while allowing the first ends <NUM> of the arms <NUM> to rotate about the central axis PBD of the pullback device <NUM>. In the depicted example, the first ends <NUM> of the arms <NUM> are sandwiched between the flange <NUM> and the locking device <NUM>.

In the examples depicted in <FIG>, the locking device <NUM> is a hollow cylinder that fits over the frame member <NUM> and the first ends <NUM> of the arms <NUM>. The locking device <NUM> includes an aperture <NUM> and the frame member includes a corresponding aperture <NUM>. A pin <NUM> is insertable into the aperture <NUM> of the locking device <NUM> and the corresponding aperture <NUM> of the frame member <NUM> for restraining the locking device <NUM> relative to the frame member <NUM>. Thus, the locking device <NUM> when restrained by the pin <NUM>, prevents both axial and radial movement of the first ends <NUM> of the arms <NUM> with respect to the central axis PBD of the pullback device <NUM> while allowing the first ends <NUM> of the arms <NUM> to rotate about the central axis PBD.

In an alternative example, the locking device <NUM> is a solid washer. In such examples, the pin <NUM> is insertable into the aperture <NUM> of the frame member <NUM> for restraining the locking device relative to the frame member <NUM>.

<FIG> is an isometric view of the collar <NUM> of the pullback device <NUM>. As shown in <FIG>, and <FIG>, the glide portions <NUM> of the collar <NUM> are attached together by connectors <NUM>. The connectors <NUM> include bores <NUM> on opposite ends, and the glide portions <NUM> include corresponding bores <NUM>. Fixtures such as bolts <NUM> are inserted through the bores <NUM> on the connectors <NUM> and the corresponding bores <NUM> on the glide portions <NUM>, and nuts <NUM> are threaded onto the bolts <NUM> to fix the glide portions <NUM> and the connectors <NUM> together. In this manner, the collar <NUM> can be secured around the base <NUM> of the rotary drill bit <NUM> (see <FIG>).

The anchors <NUM> on the base <NUM> may have a variety of configurations, shapes, and placements on the base <NUM>. Therefore, the glide portions <NUM> and connectors <NUM> may also have a variety of configurations and shapes in addition to those shown in the figures to match the configurations, shapes, and placements of the anchors <NUM> on the base <NUM>. Also, the collar <NUM> may have more than two glide portions <NUM>, or may have a single glide portion <NUM>. Also, a variety of fixtures, alternative to the bolts <NUM> and nuts <NUM>, may be used to fix the glide portions <NUM> and the connectors <NUM> together.

<FIG> is a side view of the pullback device <NUM> attached to the rotary drill bit <NUM>. During a pullback operation, pullback forces FPB from product attached to the at least one attachment location <NUM> are transmitted to the rotary drill bit <NUM> through the collar <NUM>. The collar <NUM> clamps around the base <NUM> of the rotary drill bit <NUM>. The collar <NUM> can tightly or loosely fit around the base <NUM> of the rotary drill bit <NUM> to engage portions on the base <NUM> of the rotary drill bit <NUM> that are orthogonal to the central axis RDB of the rotary drill bit <NUM> such as the surfaces <NUM>, <NUM> in the anchors <NUM>. Advantageously, by engaging the anchors <NUM>, the stability of the pullback device <NUM> during pullback is improved because the collar <NUM> prevents rotation of the pullback device <NUM>. Additionally, by engaging the base <NUM>, the collar <NUM> transfers the pullback forces FPB from the product to the base <NUM> which improves also stability during pullback because the base <NUM> is a robust portion of the rotary drill bit <NUM>.

<FIG> are front and rear views, respectively, of the pullback device <NUM> attached to the rotary drill bit <NUM>. As shown in <FIG>, the plurality of arms <NUM> fit between the plurality of vanes <NUM> on the rotary drill bit <NUM>. As described above, when the pullback device <NUM> is attached to the rotary drill bit <NUM>, the central axis PBD of the pullback device <NUM> is coincident with the central axis RDB of the rotary drill bit <NUM>. The locking device <NUM> and collar <NUM> enable the plurality of arms <NUM> to slide and rotate about the central axis RDB of the rotary drill bit <NUM> between the vanes <NUM>. This is advantageous because rotary drill bits are available in various configurations, and the vanes of a rotary drill bit may have a variety of configurations including a variety of quantities, shapes, and sizes. Thus, the ability to slide and rotate the arms <NUM> enhances the adaptability of the pullback device <NUM> for a variety of rotary drill bits.

As further shown in <FIG>, the plurality of arms <NUM> define a diameter D2 that is less than or equal to a diameter D1 of the rotary drill bit <NUM>. As shown in <FIG>, the collar <NUM> defines a diameter D3 that is less than or equal to the diameter D1 of the rotary drill bit <NUM>. The diameter D2 of the plurality of arms <NUM> and the diameter D3 of the collar <NUM> ensure that no part of the pullback device <NUM> exceeds the diameter D <NUM> of rotary drill bit <NUM>. Advantageously, this ensures that the pullback device <NUM> does not rub against the walls of a hole during a pullback operation, which may cause wear, friction, and possible failure of the pullback device <NUM>. Therefore, as shown in <FIG>, the arms <NUM> fit between adjacent vanes <NUM> in the rotary drill bit <NUM> and do not exceed the distance the vanes <NUM> protrude from the rotary drill bit <NUM>. Similarly, the collar <NUM> does not protrude beyond the diameter D1 of the rotary drill bit <NUM>.

<FIG> is an isometric view a pullback device <NUM> in accordance with another example of the present disclosure. As shown in <FIG>, the collar <NUM> of the pullback device <NUM> is attached to the base <NUM> of the rotary drill bit <NUM>. Also, the arms <NUM> of the pullback device <NUM> are positioned between the vanes <NUM> of the rotary drill bit <NUM>.

<FIG> is an isometric view of the pullback device <NUM>. As shown in <FIG>, the pullback device <NUM> includes a frame member <NUM>, a collar <NUM>, and arms <NUM>.

The frame member <NUM> has at least one attachment location <NUM>. The attachment locations <NUM> can be used to attach product to the pullback device <NUM>.

The collar <NUM> attaches the pullback device <NUM> to the base <NUM> of the rotary drill bit <NUM>. In certain examples where the rotary drill bit <NUM> includes one or more anchors <NUM>, the collar <NUM> can engage at least one anchor <NUM> on the base <NUM>. In other examples where the rotary drill bit <NUM> does not include an anchor <NUM>, the collar <NUM> can clamp around the exterior face of the base <NUM> to attach the pullback device <NUM> to the base <NUM>.

Each arm <NUM> has a first end <NUM> slidably engaged between a locking device <NUM> and the frame member <NUM>, and a second end <NUM> slidably engaged with the collar <NUM>. The arms <NUM> are slidable about the frame member <NUM> and the collar <NUM> such that the arms <NUM> can rotate about a central axis PBD of the pullback device <NUM>. The locking device <NUM> is a solid washer, and a pin <NUM> is insertable into an aperture <NUM> of the frame member <NUM> for restraining the locking device <NUM> relative to the frame member <NUM>.

<FIG> is an isometric view of the collar <NUM> in an open position. The collar <NUM> includes a pivoting arm <NUM> that can be used to hook and fasten the collar <NUM> around the base <NUM> of the rotary drill bit <NUM>. The pivoting arm <NUM> is attached at one end to the collar <NUM> by a hinge <NUM>. An additional hinge <NUM> allows a first portion <NUM> of the pivoting arm <NUM> to pivot with respect to a second portion <NUM> of the pivoting arm <NUM> to provide further flexibility in allowing the collar <NUM> to wrap around the base <NUM>. The pivoting arm <NUM> includes a latch <NUM> on an end of the first portion <NUM> that hooks onto a locket <NUM> to secure the collar <NUM> in a closed position around the base <NUM> (see <FIG>).

The pivoting arm <NUM> further includes a swivel arm <NUM> that pivots in a first direction about a hinge <NUM> to pull the latch <NUM> onto the locket <NUM> due to the pivoting arm <NUM> being connected to the swivel arm <NUM> at the hinge <NUM>. In this manner, the swivel arm <NUM> can be used to secure the collar <NUM> in the closed position around the base <NUM>. The swivel arm <NUM> pivots in a second direction about the hinge <NUM> to push the latch <NUM> off the locket <NUM> and allow the collar <NUM> to be opened.

In some examples, the swivel arm <NUM> includes a bore <NUM> that receives a locking device such as the pin <NUM> to lock the swivel arm <NUM> in place relative to the collar <NUM>, and thereby prevent the swivel arm <NUM> from pivoting about the hinge <NUM>. The pin <NUM> is an example of one type of locking device that can be used to secure the swivel arm <NUM> in place, and a variety of locking devices such as simple bolts and nuts can be used to secure the swivel arm <NUM>. In some examples, the collar <NUM> does not include the pin <NUM>.

In the example depicted in <FIG>, the collar <NUM> has a substantially circular shape to wrap around the base <NUM> of the rotary drill bit <NUM> and engage at least one surface on the base <NUM> such as the one or more anchors <NUM>. However, the collar <NUM> may have a variety of configurations, shapes, and sizes to match the configurations, shapes, sizes, and placements of the base <NUM> of the rotary drill bit <NUM>.

Each arm <NUM> has a first end <NUM> slidably engaged between a locking device <NUM> and the frame member <NUM>, and a second end <NUM> slidably engaged with the collar <NUM>. The arms <NUM> are slidable about the frame member <NUM> and the collar <NUM> such that the arms <NUM> can rotate about a central axis PBD of the pullback device <NUM>. The locking device <NUM> is secured to the frame member <NUM> by a pin <NUM> inserted in aperture <NUM>.

<FIG> is an isometric view of the collar <NUM>. As shown in <FIG>, the collar <NUM> includes two halves <NUM>, <NUM> that are secured together at corresponding attachment locations <NUM>, <NUM> by fixtures such as bolts <NUM>. Each of the halves <NUM>, <NUM> has a rounded, semi-circular shape having a substantially C shape configuration that fits around the base <NUM> of the rotary drill bit <NUM>. It is contemplated that the collar <NUM> (including the halves <NUM>, <NUM>) may have a variety of configurations, shapes, and sizes to match the configurations, shapes, sizes, and placements of the anchors <NUM> on the base <NUM> of the rotary drill bit <NUM>. Additionally, a variety of fixtures and means, alternative to the bolts <NUM> may be used to fix the halves <NUM>, <NUM> together.

Each arm <NUM> has a first end <NUM> slidably engaged between a locking device <NUM> and the frame member <NUM>, and a second end <NUM> engaged with the collar <NUM>. The locking device <NUM> is secured to the frame member <NUM> by a pin <NUM> inserted in aperture <NUM>. The collar <NUM> wraps around the second ends <NUM> of the arms <NUM>.

<FIG> is an isometric view of the collar <NUM>. In this example, the collar <NUM> is similar to a hose clamp and can be secured around the base <NUM> of the rotary drill bit <NUM> to secure the pullback device <NUM> to the base <NUM>. The collar <NUM> can be tightened by a locking mechanism <NUM> to restrain the circumference of the collar <NUM> around the base <NUM> and secure the pullback device <NUM> to the base <NUM>. The locking mechanism <NUM> can include a screw <NUM> that can be twisted to restrain the circumference of the collar <NUM>. In certain examples, the locking mechanism <NUM> works similar to a zip tie.

<FIG> are isometric views of an alternative collar <NUM> that can be used with the pullback device <NUM>. In this example, the collar <NUM> is a cable that can be opened (see <FIG>) to wrap around the second ends <NUM> of the arms <NUM> and the base <NUM>. The collar <NUM> can be tightened around the second ends <NUM> and the base <NUM> by a locking mechanism <NUM> that can be used to restrain the circumference of the collar <NUM> around the base <NUM> to secure the pullback device <NUM> to the base <NUM>. In certain examples, the locking mechanism <NUM> works similar to a zip tie.

<FIG> is an isometric view a pullback device <NUM> in accordance with another example of the present disclosure. <FIG> is a side view the pullback device <NUM> attached to the base <NUM>. As shown in <FIG>, the collar <NUM> of the pullback device <NUM> is attached to the base <NUM> of the rotary drill bit <NUM>. Also, the arms <NUM> of the pullback device <NUM> are positioned between the vanes <NUM> of the rotary drill bit <NUM>.

<FIG> is an isometric view of the pullback device <NUM>. As shown in <FIG> the pullback device <NUM> includes a collar <NUM> and a plurality of arms <NUM>. In this example, the arms <NUM> are cables that include attachment locations <NUM> at a first end. The attachment locations <NUM> can be used to attach product to the pullback device <NUM>. In alternative examples, the pullback device <NUM> may include the collar <NUM>, and the frame member <NUM>, locking device <NUM>, and arms <NUM> of the pullback device <NUM>. Also, in alternative embodiments, the arms <NUM> may be used with the collars (e.g., <NUM>, <NUM>, <NUM>, and <NUM>) in the embodiments of the pullback device that are described above.

Referring still to <FIG>, the arms <NUM> include attachment locations <NUM> at an opposite second end. The attachment locations <NUM> engage corresponding attachment locations on the collar <NUM> to secure the arms <NUM> to the collar <NUM>.

In this example, the collar <NUM> is a chain. The collar <NUM> wraps around the base <NUM> of the rotary drill bit <NUM> (see <FIG>) to secure the pullback device <NUM> to the base <NUM> of the rotary drill bit <NUM>. The collar <NUM> is secured around the base <NUM> by attaching two ends of the collar <NUM> together.

In certain examples, the collar <NUM> can include a shackle <NUM> having a shape and size that corresponds to the shape and size of the anchors <NUM> in the base <NUM>. Advantageously, the shackle <NUM> aligns and mates with the orthogonal surfaces <NUM>, <NUM> in the base <NUM> of the rotary drill bit <NUM> and ensures that the collar <NUM> does not rotate or move with respect to the base <NUM> during pullback.

<FIG> is an isometric view of the pullback device <NUM> in an open position. <FIG> are isometric views of the pullback device <NUM> in a closed position. <FIG> are top and bottom views, respectively, of the pullback device <NUM> in the closed position. Referring now to <FIG>, the pullback device <NUM> includes a frame member <NUM>, a collar <NUM>, and arms <NUM>. Each arm <NUM> has a first end <NUM> pivotally and slidably engaged in a groove <NUM> in the frame member <NUM>, and a second end <NUM> slidably engaged with grooves <NUM> in opposing halves <NUM>, <NUM> of the collar <NUM>.

The first ends <NUM> of the arms <NUM> include ballpoint pivot joints that engage the groove <NUM> allowing the arms <NUM> to pivot with respect to the frame member <NUM>. The ballpoint pivot joints are also slidable in the groove <NUM> about the frame member <NUM> such that the arms <NUM> can rotate about a central axis PBD of the pullback device <NUM>.

A locking device <NUM> is insertable through an aperture <NUM> of the frame member <NUM> and fits around an extension <NUM> of each arm <NUM> forming a locking portion (e.g., hook-shaped) for restraining the pivotal movement of the arms <NUM> with respect to the frame member <NUM> when the pullback device <NUM> is in the closed position. Thus, the frame member <NUM> is formed as a collar, slidable along the locking device <NUM>. A pin <NUM> can be inserted through the locking device <NUM> for securing the locking device <NUM> relative to the frame member <NUM> in the axial direction with respect to the central axis PBD of the pullback device <NUM>. Additionally, the locking device <NUM> has at least one attachment location <NUM>. The attachment location <NUM> can be used to attach product to the pullback device <NUM> when the locking device <NUM> is secured to the frame member <NUM> with the pin <NUM>.

The collar <NUM> includes halves <NUM>, <NUM> that pivot between the open and closed positions when the first ends <NUM> of the arms <NUM> pivot in the groove <NUM> of the frame member <NUM>. In the closed position, the locking device <NUM> insertable through the frame member <NUM> to fit over the extensions <NUM> to prevent the arms <NUM> from pivoting and to thereby lock the halves <NUM>, <NUM> of the collar <NUM> together. In this manner, the collar <NUM> can be locked around the base <NUM> of the rotary drill bit <NUM>.

Each of the halves <NUM>, <NUM> include grooves <NUM> that allow the arms <NUM> to slide with respect to the collar <NUM> while the arms <NUM> are prevented by the locking device <NUM> from pivoting with respect to the frame member <NUM>. As shown, the second ends <NUM> of the arms <NUM> are secured in the grooves <NUM> by a fixture <NUM> such as a bolt and nut.

Each of the halves <NUM>, <NUM> has a rounded, semi-circular shape, such as a substantially C shape configuration, that fits around the base <NUM> of the rotary drill bit <NUM>. It is contemplated that the collar <NUM> (including the halves <NUM>, <NUM>) may have a variety of configurations, shapes, and sizes to match the configurations, shapes, and placements of the anchors <NUM> on the base <NUM> of the rotary drill bit <NUM>.

<FIG> illustrates a method <NUM> of installing product in a hole. The method <NUM> includes a step <NUM> of using a rotary drill bit having a plurality of vanes and cutters to drill a hole from a start location at an uphole end to an end location at a downhole end.

Next, the method <NUM> includes a step <NUM> of attaching a pullback device to a base of the rotary drill bit at the end location. A trench can be dug at a downhole end to facilitate attachment of the pullback device to the rotary drill bit after completion of the drilling operation so that the pullback device can be used to install product in the ground during a pullback operation. In some examples, the trench is an end location.

Step <NUM> includes positioning a plurality of arms of the pullback device between the plurality of vanes before attaching a collar of the pullback device to the base. In some examples, step <NUM> includes inserting a locking device onto the pullback device, the locking device allowing the plurality of arms to rotate about a central axis of the pullback device while preventing radial and axial movement between the plurality of arms and the pullback device. In some examples, step <NUM> includes inserting a pin through an aperture in the pullback device for restraining the locking device relative to the pullback device.

Next, the method <NUM> includes a step <NUM> of attaching product to the pullback device at the end location. In step <NUM>, the product can be directly attached to an attachment location on the pullback device or can be indirectly attached to an attachment location on the pullback device by connecting the product first to a swivel device, and then connecting the swivel device to an attachment location on the pullback device. The swivel device can prevent the product from rotating about the central axis of the rotary drill bit inside the hole when the pullback device is pulled back through the hole.

Next, the method <NUM> includes a step <NUM> of pulling back the rotary drill bit from the end location to the start location. During pullback, the drill rod assemblies are removed from the drill string as the drill string is pulled back through the hole.

Next, the method <NUM> includes a step <NUM> of detaching the product from the pullback device at the start location. After the product is detached, the product is left installed in the hole. In some examples, step <NUM> of the method <NUM> may include removing the pin from the pullback device, removing the locking device from the pullback device, disengaging the collar from the base of the rotary drill bit, and removing the pullback device from the rotary drill bit.

<FIG> illustrates a method <NUM> of pulling back product in a hole drilled by a rotary drill bit coupled to a distal end of a drill string. The rotary drill bit has a base defining a central axis about which the rotary drill bit rotates during drilling and a plurality of vanes extending from the base. Each vane has a plurality of cutters. The method <NUM> includes a step <NUM> of positioning an anchoring portion of a pullback device between the plurality of vanes on the rotary drill bit. Next, the method <NUM> includes a step <NUM> of attaching the anchoring portion to the rotary drill bit. Next, the method <NUM> includes a step <NUM> of attaching the product to a product attachment portion of the pullback device. Next, the method <NUM> includes a step <NUM> of pulling back the product through the hole by transferring a pullback load from the anchoring portion of the pullback device to the base of the rotary drill bit. In certain examples, the pullback load is transferred from the anchoring portion to at least one surface on the base, the at least one surface being orthogonal to the central axis of the rotary drill bit.

<FIG> illustrate a pullback system 10A of yet another embodiment, including a pullback device <NUM> and a rotary drill bit 200A. Consistent with preceding embodiments, the attachment location <NUM> can be positioned along the central axis PBD of the pullback device <NUM>, which is coincident with the central axis RDB of the rotary drill bit 200A. The rotary drill bit 200A is similar to the drill bit <NUM> of the preceding description and figures, including a base <NUM>, a plurality of vanes <NUM> at a forward end, and a coupler <NUM> at a rearward end (e.g., with threads, not shown). However, the drill bit 200A can be provided with or without the anchor <NUM> of the drill bit <NUM>. Whether or not an anchor <NUM> is provided, the pullback device <NUM> does not utilize a separate collar secured to the anchor. Rather, individual arms <NUM> of the pullback device <NUM> are provided as grapple arms to engage with arm engagement features 212A, which as illustrated, are provided in the troughs <NUM> between the vanes <NUM> of the rotary drill bit 200A. The arms <NUM> attach to the rotary drill bit 200A, forming an anchoring portion of the pullback device <NUM>. As shown in the drawings, the arm engagement features 212A are located within the axial extent of the vanes <NUM>. Being within the axial extent of the vanes <NUM> simply refers to the engagement features 212A being positioned within the axial span defined between a front or distal end of the rotary drill bit 200A (e.g., of the vanes <NUM>) and the opposite or back edges of the vanes <NUM>. In other constructions, the arm engagement features 212A may be located on the base <NUM> beyond the back edges of the vanes <NUM> (i.e., to the left as shown in <FIG>). In either case, the arms <NUM> of the pullback device <NUM> extend through the troughs <NUM> when the second ends <NUM> of the arms <NUM> are engaged with the arm engagement features 212A and the pullback device <NUM> is in its assembled state as shown in <FIG>. In the assembled state, the outer radial edges of the arms <NUM>, which can be the radially outermost portions of the pullback device <NUM>, are positioned radially inward of the diameter D1 of the rotary drill bit 200A defined by the vanes <NUM>.

As shown in the cross-section view of <FIG>, each arm engagement feature 212A is formed by a localized absence of material at a particular location along an outer peripheral wall of the rotary drill bit 200A, in the trough <NUM> between the vanes <NUM>. The arm engagement features 212A can be recesses, pockets, undercuts, or other concavities, or in some constructions, apertures. As shown in <FIG>, an end surface <NUM> of each arm engagement feature 212A that lies nearest the distal (drilling) end of the rotary drill bit 200A can be skewed from the axis RDB rather than perpendicular. The end surface <NUM> can be skewed in a direction that increases the security of the engagement between the rotary drill bit 200A and the pullback device <NUM> during pullback operations. Furthermore, it can be seen in <FIG>, that the arm second ends <NUM> can be formed as hooks that project radially inward toward the axis RDB. In some constructions, each hooked second end <NUM> can define a hook surface <NUM> having a similar skew angle configured so that the hook surface <NUM> lies along the end surface <NUM> when the pullback device <NUM> is assembled onto the rotary drill bit 200A.

Unlike many of the other arms disclosed in the preceding embodiments, although similar in many respects to the pullback device <NUM> of <FIG>, the arms <NUM> are pivotally coupled at their first ends <NUM> to the frame member <NUM> such that the frame member <NUM> forms an axially slidable collar as part of a collar assembly <NUM>, which is best described with reference to the exploded assembly view of <FIG>. Thus, the pullback device <NUM> may form a grapple assembly. In the illustrated construction, the pivotal connection is established by an aperture through the first end <NUM> along with parts of the collar assembly <NUM> forming a clevis structure <NUM> and a clevis pin <NUM> (e.g., threaded bolt assembled with clevis structure <NUM>, for example with washer(s) and a nut as shown). The pivotal connection for each arm <NUM> is configured to allow the second end <NUM> of that arm <NUM> to pivot radially inward toward the axis RDB for assembly and radially outward away from the axis RDB for disassembly, while retained to the collar assembly <NUM>. The collar assembly <NUM> as illustrated includes the frame member <NUM> providing a main collar body having a ring portion <NUM> and the individual clevis structures <NUM>, and a separate ring or washer <NUM> forming an abutment surface of the collar assembly <NUM>. The collar assembly <NUM> is arranged around a locking device <NUM> of the pullback device <NUM> and slidable axially along the locking device <NUM> between locking and unlocking positions as described in further detail below. The abutment surface provided by the washer <NUM> faces and abuts the pin <NUM> that is removably received in the aperture <NUM> of the locking device <NUM> to retain the collar assembly <NUM> in the locking position (<FIG> and <FIG>), thus maintaining the pullback device <NUM> in the assembled state on the rotary drill bit 200A.

Between the first and second ends <NUM>, <NUM>, each arm <NUM> further includes a radially-inward projecting part, or extension, forming a locking portion <NUM>. The locking portions <NUM> can be generally hook-shaped. As illustrated, each of the locking portions <NUM> includes a radially inward extending portion and a connecting axially extending portion, the axially extending portion extending in a direction toward the collar assembly <NUM> and away from the rotary drill bit 200A.

From the unassembled state, just after drilling and prior to pullback operation, the pullback device <NUM> is brought axially into proximity with the rotary drill bit 200A such that they overlap with each other as shown in <FIG>. The second arm ends <NUM> are brought into register with the arm engagement features 212A in the rotary drill bit 200A. The pin <NUM> is removed, and the collar assembly <NUM> is in the unlocking position. In the unlocking position, the collar assembly <NUM> can be slid relatively away from the attachment location <NUM> and may abut a shoulder formed at the edge of the locking device <NUM>. Each arm <NUM> is pivoted about its first end <NUM> so that its second end <NUM> is engaged with (e.g., inserted into) the respective arm engagement features 212A on the rotary drill bit 200A. It is noted here that the arm engagement features 212A can be provided in a number (e.g., three) matching that of the arms <NUM>, or alternately, excess arm engagement features 212A can be provided (e.g., one in every trough <NUM>). In some constructions, the pullback device <NUM> has additional arms <NUM>, for example four or five.

As the arms <NUM> are pivoted to engage the arm engagement features 212A, the arm locking portions <NUM> pivot toward or into the locking device <NUM>. The locking device <NUM> is formed as a ring (e.g., integral with the attachment location <NUM> or securely attached thereto) and is open on the end facing the rotary drill bit 200A. Once all the second ends <NUM> of the arms <NUM> are inserted into the arm engagement features 212A, the collar assembly <NUM> is moved along the locking device <NUM> toward the attachment location <NUM> and away from the rotary drill bit 200A, into the locking position of the collar assembly <NUM>, so that all the arm locking portions <NUM> are pulled into, or further into, the locking device <NUM> as shown in <FIG> and <FIG>. With the collar assembly <NUM> in the locking position, insertion of the arm locking portions <NUM> prevents outward pivoting of the arms <NUM>, which in turn prevents release of the arm second ends <NUM> from the rotary drill bit 200A. Once the collar assembly <NUM> is moved into the locking position, the pin <NUM> is inserted into the aperture <NUM> just below the collar assembly <NUM> (e.g., the washer <NUM>) to maintain the collar assembly <NUM> in the locking position. One or more pin retainer <NUM> is used to keep the pin <NUM> in place. The pin retainer <NUM> can be a set screw as shown, e.g., oriented perpendicular to the pin <NUM>. However, pin retainer(s) <NUM> can take other forms, including by non-limiting example, a cotter pin, a circlip, a wire, or a nut.

The pullback system 10A provides one example of a pullback device <NUM> with multiple arms <NUM>, each of which interfaces or joins (e.g., directly) with an engagement feature 212A provided in the rotary drill bit 200A to form an anchoring portion of the pullback device <NUM>. The second ends <NUM> of the arms <NUM> that engage directly with the rotary drill bit 200A are not mutually collared or interconnected together. The second arm ends <NUM> form individual joints with the rotary drill bit 200A that transmit the pullback loads from the rotary drill bit 200A to the pullback device <NUM> during installation of product into the hole.

<FIG> illustrate a pullback system 10B including a pullback device <NUM> and a rotary drill bit 200B. The pullback system 10B is similar in most respects to the pullback system 10A of <FIG>, and thus the preceding disclosure is relied upon in reference to similarities while the description below is focused upon those aspects that differentiate the pullback system 10B. First, it is noted that <FIG> illustrate only a portion of the pullback device <NUM>, with the understanding that the pullback device <NUM> includes multiple (e.g., three) arms <NUM> like the pullback device <NUM> of <FIG>. Furthermore, the arms <NUM> can be coupled together via a collar assembly <NUM> (at first ends <NUM>) including a frame member <NUM>, and a locking device <NUM> (at locking portions <NUM>) as shown with the pullback device <NUM>.

At the second end <NUM> of each arm <NUM> of the pullback device <NUM>, rather than a hook portion for engaging a concave pocket or recess in the trough <NUM> between drill bit vanes <NUM>, an eye <NUM> is formed, providing an aperture. In other constructions, the aperture can be provided by way of another structure, without an eye per se. The aperture of the eye <NUM> is configured to align with a corresponding engagement feature 212B and to receive a corresponding fastener <NUM>. In some constructions, the engagement feature 212B is a threaded aperture and the fastener <NUM> is a threaded fastener. The fastener <NUM> can be received by the engagement feature 212B along a radially inward direction. In other constructions, the fastener <NUM> can be received along a skew direction having a radially inward component. The threaded apertures or other engagement features 212B are provided at some or all of the troughs <NUM> between vanes <NUM>. Although the details are not repeated here, the various arms <NUM> are retained by the locking device <NUM> when the collar assembly <NUM> is moved into the locking position, and the pin <NUM> retains the collar assembly <NUM> in place during use. It is also contemplated that a modified version of the pullback system 10B can forego the slidable, lockable collar assembly <NUM>. Likewise, the arms <NUM> may be provided without the locking portions <NUM>. In some constructions, the arms <NUM> are not pivotally supported at their first ends <NUM>. For example, the arms <NUM> may be fixed to a frame member and attachment location.

<FIG> illustrate a pullback system 10C including a pullback device <NUM> and a rotary drill bit 200C. The pullback system 10C is similar in most respects to the pullback systems 10A of <FIG> and 10B of <FIG>, and thus the preceding disclosure is relied upon in reference to similarities while the description below is focused upon those aspects that differentiate the pullback system 10C. First, it is noted that <FIG> illustrate only a portion of the pullback device <NUM>, with the understanding that the pullback device <NUM> includes multiple (e.g., three) arms <NUM> like the pullback device <NUM> of <FIG>. Furthermore, the arms <NUM> can be coupled together via a collar assembly <NUM> (at first ends <NUM>) including a frame member <NUM>, and a locking device <NUM> (at locking portions <NUM>) as shown with the pullback device <NUM>.

At the second end <NUM> of each arm <NUM> of the pullback device <NUM>, rather than a hook portion for engaging a concave pocket or recess in the trough <NUM> between drill bit vanes <NUM>, an aperture <NUM> is provided. The arm <NUM> at the location of the aperture <NUM> may be formed as an eye, or may have no conspicuous change in structure as shown. The aperture <NUM> is configured to align with a corresponding engagement feature 212C formed in a corresponding vane <NUM> (e.g., adjacent a rearward end of the vane <NUM>) rather than in the trough <NUM>. The aperture <NUM> receives a corresponding fastener <NUM> to secure the arm <NUM> to the rotary drill bit 200C. In some constructions, the engagement feature 212C is a through hole and the fastener <NUM> is a retaining pin, for example a clevis pin. The illustrated clevis pin <NUM> has a head at one end and a through hole at the opposite end for receiving a cotter pin <NUM>. However, the retaining pin or other fastener <NUM> can take other particular forms in other embodiments. In particular, either one of the arm aperture <NUM> and the engagement feature 212C can be threaded for receiving a threaded fastener. As illustrated, the engagement feature 212C is a cross hole. In particular, the fastener <NUM> can be received by the engagement feature 212C along a direction perpendicular to the radial direction. For example, the fastener <NUM> can extend tangentially through the engagement feature 212C, perpendicular to the central axis RDB of the rotary drill bit 200C. In other constructions, the fastener <NUM> can be received along a skew direction having a tangential component. Although not attached within the troughs <NUM>, the arms <NUM> occupy the troughs <NUM> and do not extend radially outward of the vanes <NUM>. The through holes or other engagement features 212C are provided in some or all of the vanes <NUM>. Although the details are not repeated here, the various arms <NUM> are retained by the locking device <NUM> when the collar assembly <NUM> is moved into the locking position, and the pin <NUM> retains the collar assembly <NUM> in place during use. In a modified embodiment, the engagement feature 212C can be formed in the trough <NUM> by a separate structure protruding radially from the hub or body portion of the rotary drill bit 200C between the vanes <NUM>. It is also contemplated that a modified version of the pullback system 10C can forego the slidable, lockable collar assembly <NUM>. Likewise, the arms <NUM> may be provided without the locking portions <NUM>. In some constructions, the arms <NUM> are not pivotally supported at their first ends <NUM>. For example, the arms <NUM> may be fixed to a frame member and attachment location.

<FIG> illustrate a pullback system 10D including a pullback device <NUM> and a rotary drill bit 200D. The pullback system 10D is similar in most respects to the pullback systems 10A, 10B, and 10C, and thus the preceding disclosure is relied upon in reference to similarities while the description below is focused upon those aspects that differentiate the pullback system 10D. First, it is noted that <FIG> illustrate only a portion of the pullback device <NUM>, with the understanding that the pullback device <NUM> includes multiple (e.g., three) arms <NUM> like the pullback device <NUM> of <FIG>. Furthermore, the arms <NUM> can be coupled together via a collar assembly <NUM> (at first ends <NUM>) including a frame member <NUM>, and a locking device <NUM> (at locking portions <NUM>) as shown with the pullback device <NUM>.

An aperture <NUM> is provided through the second end <NUM> of each arm <NUM> of the pullback device <NUM>. The arms <NUM> can be identical to the arms <NUM> shown in <FIG>, or may have an eye like the arms <NUM>, or another alternate construction. The apertures <NUM> of the various arms <NUM> are configured to align (circumferentially) with a corresponding plurality of engagement features 212D formed in the vanes <NUM> (e.g., adjacent a rearward end of the vane <NUM>) rather than in the trough <NUM>. As illustrated, the engagement features 212D are concave grooves or "cradles" that extend circumferentially. The engagement features 212D are formed as recesses or undercuts in the rearward edges of the vanes <NUM>. However, the engagement features 212D can take different forms, such as apertures through the vanes <NUM> and certainly grooves or recesses of other shapes. The shape of the illustrated engagement features 212D is a rounded groove (e.g., "U" shaped), but the engagement features 212D can be shaped as a "V" or even a rectangular groove. The apertures <NUM> receive a corresponding fastener <NUM> to collectively secure the arms <NUM> to the rotary drill bit 200D. The fastener <NUM> can be a flexible loop (e.g., of wire, cable, chain, etc.) or loops threaded through all the apertures <NUM> of all the arms <NUM> and also seated or nested into all the grooves forming the engagement features 212D. The illustrated fastener <NUM> has two opposing ends 1368A, (e.g., loop ends) that are secured together by a connector (e.g., cable tie, padlock, locking ring, not shown) to keep the fastener <NUM> in position on the rotary drill bit 200D. The fastener <NUM> forms a unitary circumferential loop or ring for retaining the arms <NUM> rather than having separate connections to the rotary drill bit 200D for each arm <NUM>. Although not attached within the troughs <NUM>, the arms <NUM> occupy the troughs <NUM> and do not extend radially outward of the vanes <NUM>. The engagement features 212D are provided in some or all of the vanes <NUM>. Although the details are not repeated here, the various arms <NUM> are retained by the locking device <NUM> when the collar assembly <NUM> is moved into the locking position, and the pin <NUM> retains the collar assembly <NUM> in place during use. It is also contemplated that a modified version of the pullback system 10D can forego the slidable, lockable collar assembly <NUM>. Likewise, the arms <NUM> may be provided without the locking portions <NUM>. In some constructions, the arms <NUM> are not pivotally supported at their first ends <NUM>. For example, the arms <NUM> may be fixed to a frame member and attachment location.

<FIG> illustrate a pullback system 10E including a pullback device <NUM> and a rotary drill bit 200E. The pullback system 10E is similar in most respects to the pullback systems 10A, 10B, and 10C, and thus the preceding disclosure is relied upon in reference to similarities while the description below is focused upon those aspects that differentiate the pullback system 10E. First, it is noted that <FIG> illustrate only a portion of the pullback device <NUM>, with the understanding that the pullback device <NUM> includes multiple (e.g., three) arms <NUM> like the pullback device <NUM> of <FIG>. Furthermore, the arms <NUM> can be coupled together via a collar assembly <NUM> (at first ends <NUM>) including a frame member <NUM>, and a locking device <NUM> (at locking portions <NUM>) as shown with the pullback device <NUM>.

The second end <NUM> of each arm <NUM> of the pullback device <NUM> includes a flange portion having an aperture <NUM>. Due to the configuration of the second end <NUM> (being bent <NUM>-degrees or otherwise forming the flange portion), the aperture <NUM> extends through the arm <NUM> in a direction parallel to the arm <NUM>. The aperture <NUM> is configured to align with a corresponding engagement feature 212E formed as an apertured boss or mounting block. The engagement feature 212E is positioned within the trough <NUM>, but may be conjoined with an adjacent vane <NUM> as shown. The engagement features 212E can be provided along the rearward half of the axial length of the vanes <NUM>. The aperture <NUM> receives a corresponding fastener <NUM> to secure the arm <NUM> to the rotary drill bit 200E. In some constructions, the aperture of the engagement feature 212E is a through hole and the fastener <NUM> is a threaded fastener secured with a nut as shown. However, in other constructions, the engagement features 212E may be threaded. The fastener <NUM> can be received by the engagement feature 212E along a direction parallel to the central axis RDB of the rotary drill bit 200E. As with the other embodiments, the arms <NUM> occupy the troughs <NUM> and do not extend radially outward of the vanes <NUM>. The engagement features 212E are provided in between each adjacent pair of vanes <NUM>, or only selected ones thereof. Although the details are not repeated here, the various arms <NUM> are retained by the locking device <NUM> when the collar assembly <NUM> is moved into the locking position, and the pin <NUM> retains the collar assembly <NUM> in place during use. It is also contemplated that a modified version of the pullback system 10E can forego the slidable, lockable collar assembly <NUM>. Likewise, the arms <NUM> may be provided without the locking portions <NUM>. In some constructions, the arms <NUM> are not pivotally supported at their first ends <NUM>. For example, the arms <NUM> may be fixed to a frame member and attachment location.

Claim 1:
A pullback device (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) for horizontal directional drilling operations using a rotary drill bit (<NUM>) having a plurality of vanes (<NUM>) defining a cutting portion, the pullback device attaching to a base (<NUM>) of the rotary drill bit (<NUM>) without disassembling or removing the rotary drill bit (<NUM>) from a drill string, the pullback device comprising:
a product attachment portion (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) configured to align with a central axis (RDB) of the rotary drill bit (<NUM>) and to attach product to the pullback device (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>); and
an anchoring portion including
a collar (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) configured to clamp around the base (<NUM>) and engage with at least one anchor (<NUM>) provided in the base (<NUM>) of the rotary drill bit (<NUM>) such that the collar (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) is configured to transfer pullback forces and also prevent rotation of the pullback device (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) on the rotary drill bit (<NUM>), and
a plurality of arms (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) configured to fit between the plurality of vanes (<NUM>) of the rotary drill bit (<NUM>) when the collar (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) is engaged with the at least one anchor (<NUM>) in the base (<NUM>).