Handheld Cable Handling Accessories

Abstract

A threading accessory comprising a belt and two rotatable wheels configured to rotate the belt, the belt having a circumferential groove formed in an outer circumferential surface thereof configured to receive and retain a portion of a thread therein, and one or more pressure wheels are used to abut a portion of the belt passing between the rotating wheels and elastically deform the portion of the belt to at least partially latch over and propel the portion of the thread within the circumferential groove for propulsion by the belt.

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates generally to cable handling devices and methods of use, and more particularly to a handheld cable handling accessory that can be used to thread draw tape through raceways. [Background technology]

[0002] This section is intended to provide background information related to the present application that is not necessarily prior art.

[0003] A draw tape (also known as a draw wire, fish tape, stalband, or electrician's snake) is a tool commonly used by electricians to thread new wiring through walls and conduits (metal or plastic pipes used to protect electrical wiring). Typically, draw tapes are made of thin strips of spring steel or fiberglass cable. By carefully manipulating the draw tape, it can be steered and threaded into restricted spaces such as wall cavities and conduits. Draw tapes are configured to install electrical cables / wires for various types of wiring such as electrical cables / wires, telephone cables / wires, network cables, speaker wires, etc., by pushing its tip into a curved passage, bending it towards a distal opening, and pulling it back, for example, using a guide string.

[0004] Draw tape is usually wrapped / spooled on a plastic / metal reel, with an inherent curvature to facilitate threading through electrical conduit. This allows the tip of the draw tape to be slightly oriented by manipulating the reel. The draw tape is usually stiff enough that it can be pushed in the direction the draw tape is pointing. In this way it can be forced through an empty wall cavity or conduit for the wire / cable to be installed.

[0005] A typical wire / cable installation involves manually threading the end of the draw tape through a proximal opening in a conduit (e.g., in an electrical cabinet, junction box, electrical plug, lamp outlet, etc.) and then manually pushing the draw tape in a distal direction so that the distal end exits the distal opening. An electrical cable / wire is then attached to the end of the draw tape at the distal opening of the conduit and the draw tape is pulled back (proximally) to bring the electrical cable along and install it between the conduit openings.

[0006] This traditional manual wire threading technique is limited by mechanical complexities and can be prone to failure. Manually pushing the draw tape into the conduit and manually pulling it back with the electrical cable / wire attached to its distal end is a difficult and tiring task, especially when there are corners / curves and long distances. Electricians are often required to install multiple (dozens) of electrical cables / wires on building walls every day, which can be a painful burden and cause tendon / muscle / ligament injuries due to overuse.

[0007] Cable / draw tape threading solutions known from the patent literature are briefly described in the following paragraphs.

[0008] International Patent Publication WO2020 / 261259 discloses a method and device for driving a draw tape. In some embodiments, a portion of the draw tape is loaded into a drive. Optionally, an actuator connected to the drive moves the tape longitudinally relative to the drive. For example, a distal portion of the tape and / or its distal tip is driven out of and / or into the outlet opening of the drive. Optionally, the drive drives the distal tip of the tape into or out of the conduit by holding the outlet opening of the drive near the opening of the conduit. In some embodiments, the tape is driven by a friction wheel. In some embodiments, power is provided by a power tool (e.g., a power screwdriver) reversibly attached to the drive.

[0009] Chinese Patent Publication CN110021895 discloses a threading machine including a machine body and a driving device, the machine body is provided with a transmission part therein, the driving device is transmission-connected with the transmission part, the upper end of the machine body is provided with a threading guide part, the threading guide part is provided with a left synchronous belt and a right synchronous belt, a left driving pulley and a right driving pulley are respectively arranged on both sides in the longitudinal direction of the upper end of the machine body, a left driven pulley is arranged on the right side of the left driving pulley at the upper end of the machine body, a right driven pulley is arranged behind the right driving pulley at the upper end of the machine body, a synchronous belt is arranged outside the left driving pulley and the left driven pulley, the right synchronous belt is arranged outside the right driving pulley and the right driven pulley, and the gap between the left synchronous belt and the right synchronous belt serves as a threading gap. According to this threading machine, the synchronism of the traction threading lead is high, and the synchronous traction of the cable is carried out by the mutual clamping of the left synchronous belt and the right synchronous belt, and the transmission process needs to output power to the left driving pulley and the right driving pulley, and the left driven pulley, the right driven pulley, the additional left intermediate pulley and the additional right intermediate pulley are driven by the synchronous belt.

[0010] China Utility Model Publication CN209786652 discloses a threading machine with two sets of oppositely arranged driving belt wheels, two sets of oppositely arranged driven belt wheels, and a synchronous belt. Two driving belt wheels are arranged on the right side of the upper end of the machine body, and two driven belt wheels are arranged on the left side of the upper end of the machine body, and synchronous belts are respectively arranged in a sleeve shape between the rear driving belt wheel and the rear driven belt wheel, and between the front driving belt wheel and the front driven belt wheel. Two driven spindles are arranged on the left side of the machine body, two transmission spindles are arranged on the right side of the machine body, and a lead groove tightening adjustment assembly for adjusting the distance between the driven spindles is arranged on the machine body. This synchronous traction device has the advantages that the synchronism of the traction threading lead is high, and the synchronous traction of the cable is performed by the mutual clamping of the front synchronous belt and the rear synchronous belt, and in the transmission process, only the power is output to the driving belt wheel on one side, and the synchronous belts on both sides can be synchronously driven.

[0011] Chinese Utility Model Publication CN208874187 discloses a steel wire traction device in which a steel wire passes through a wire pipe of a building or structure and uses a staggered wheel set of a steel wire traction wire. The device is characterized in that a driving wheel set of a wedge-shaped grooved wheel and a driven wheel set of a pulley are arranged in a straight line in the vertical direction and in a staggered manner in the horizontal direction. The power mechanism, the reduction mechanism and the driving wheel set are connected in sequence, the driven wheel set is connected to a pressure adjustment mechanism, the steel wire is arranged longitudinally in the staggered gap, and the pressure adjustment mechanism is adjusted so that the driven wheel set can slide laterally relative to the driving wheel set, thereby adjusting the elastic deformation of the steel wire. The power mechanism can adopt a hand-held electric drill. According to the device, the stress area of ​​the steel wire is increased by the elastic deformation of the steel wire, and a sufficient friction force is generated to transport the steel wire on the wedge-shaped grooved wheel. In practical operation, the wear of the wheel set and the steel wire is small, and the transporting and pulling capacity of the steel wire is improved by several times compared with the prior art. The present invention further provides a staggered wheel set dual wire pulling device, which can carry or pull two wires at the same time. Summary of the Invention

[0012] There is a need in the art for a simplified handheld cable / wire threading device that is connectable to or actuable by a selected handheld actuator to manipulate (i.e., push or pull) a cable / wire within a selected medium. Such medium may be, for example, a wall, a conduit, a concealed or unconcealed cable / wire tunnel mounted inside or outside the wall of a building, an underground cable / wire passageway in an urban area, etc. Cable / wire threading devices heretofore known in the patent literature are mechanically complex, difficult to operate, and expensive to manufacture.

[0013] The embodiments disclosed herein provide a handheld cable / wire threading accessory configured to be actuated by a handheld actuator (e.g., power drill or screwdriver) that can be used to effectively and controllably thread / manipulate (push / pull) the draw tape. However, it will be apparent that the disclosed embodiments are not limited to implementation as a handheld tool / accessory, and that the same principles and features can equally be used to implement a stationary (or wheeled / steerable) threading device that can be actuated by any suitable integrally attached or reversibly connectable actuator (e.g., electric, combustion, or pneumatic engine).

[0014] It should also be noted that the embodiments disclosed herein are not limited to threading draw tapes (e.g., stainless steel or fiberglass) through electrical conduits or installing wires / cables. In fact, the disclosed embodiments can be used to thread any type of cable / plumbing or pipe / conduit that has sufficient stiffness to be pushed and pulled longitudinally to thread through any type of concealed (or unconcealed) passageway for any purpose, including, but not limited to, installing elastically (or flexibly) deformable wires / cables or (e.g., pneumatic) pipes / conduits or fiber optic cables, monitoring and / or removing blockages / clogging (e.g., in building walls, cable / plumbing tunnels, or sewer / drain pipes / passageways), measuring the distance of such passageways, etc. For this reason, the embodiments disclosed herein are generally referred to herein as threading accessories, and the wires, cables, draw tapes, or pipes / conduits manipulated thereby are generally referred to herein as pushable threads or threads.

[0015] An embodiment of the threading accessory includes a push unit configured to impart a backward or forward (push-pull) motion to a portion of the pushable thread, which can be spooled into a thread / draw tape container connectable to the push unit. In a possible embodiment, a transmission unit is used to mechanically couple the push unit to a handheld actuator. The thread / draw tape container can be rotated in one direction to push a portion of the pushable thread therefrom and rotated in the opposite direction to push a portion of the pushable thread into and spooled within the thread / draw tape container.

[0016] The propulsion unit, in some embodiments, utilizes two rotating wheels and a grooved belt (having a central circumferential groove) coupled to (mounted on and / or stretched over) the rotating wheels to transfer rotational motion of the hand-held actuator (e.g., received via a transmission unit) to the rotating wheels and the grooved propulsion belt coupled thereto. In some embodiments, the grooved belt has an inner engagement side for mechanically coupling to the rotating wheels and an outer propulsion side having a circumferential groove configured to receive and securely hold a portion of the propulsable sled.

[0017] Optionally, but preferably in some embodiments, the propulsion unit is configured to form a defined belt pressing gap between the rotating wheels. The belt pressing gap is configured to press a portion of the grooved belt to elastically deform on the propulsible sled, thereby substantially increasing the frictional and holding force on the propulsible sled. One or more rollers (e.g., cam followers) may be used in the belt pressing gap of the propulsion unit to press and hold the portion of the propulsible sled against the grooved propulsion belt. More specifically, the one or more rollers are adapted to press a portion of the propulsible sled passing through the belt pressing gap of the propulsion unit against a portion of the circumferential groove of the grooved propulsion belt, thereby causing deformation of the grooved propulsion belt pressed against the portion of the propulsible sled, thereby tightly holding and propelling the portion of the propulsible sled due to the increased frictional / holding force obtained therebetween.

[0018] Accordingly, embodiments of the present application relate to a threading accessory including a propelling unit configured to manipulate a portion of a propellable sled passing therethrough. The propelling unit includes a propelling belt coupled / tensioned between two rotating wheels, the propelling belt having a circumferential groove configured to receive and hold the portion of the propellable sled and a deformable region defined internally about the circumferential groove. A belt pressure zone can be defined between the rotating wheels and configured to elastically deform the deformable region therein to overlie a significant circumferential portion of the propellable sled, thereby increasing friction / retention between the portion of the propellable sled held within the circumferential groove. The threading accessory may also include a transmission unit configured to receive and transmit an external rotational motion to the propelling unit for actuating at least one of the rotating wheels.

[0019] One or more rollers may be used in the belt pressure zone to apply pressure / force to elastically deform the deformable region of the propelled belt. Optionally, the threading device includes a tiltable thread / draw tape receptacle configured to assume an adjustable tilt angle in response to propelling (pushing / pulling) a portion of the propellable thread.

[0020] A method of threading a propulsible sled by a threading accessory may include coupling an actuator to a transmission unit of the threading accessory and actuating the actuator to transmit rotational motion in a first rotational direction to the transmission unit, thereby rotating a propulsion belt of the propulsion unit. A circumferential groove in the propulsion belt is configured to receive and retain a portion of the propulsible sled and to elastically deform a deformable region of the propulsion belt to overlie a significant circumferential portion of the propulsible sled and increase friction / retention between the portion of the propulsible sled retained within the circumferential groove of the propulsion belt. In this manner, the propulsible sled may be propelled from the propulsion unit in a first axial direction.

[0021] The method may further include actuating the actuator to transmit rotational motion in a second rotational direction opposite to the first rotational direction to the transmission unit, thereby rotating a propulsion belt of the propulsion unit to draw the propulsable sled in a second axial direction opposite to the first axial direction into the propulsion unit for winding into the sled / draw tape receptacle.

[0022] Optionally, but preferably in some embodiments, the threading accessory is configured to be carried by an external actuator device attached to its transmission unit, such that the threading accessory can be transported, manipulated, and / or operated using only the external actuator device, without an operator's hands ever touching the threading accessory.

[0023] In one aspect, a threading accessory is provided that includes a belt and two rotatable wheels configured to rotate the belt. The belt has a circumferential groove formed in an outer circumferential surface thereof configured to receive and retain a portion of a thread therein. The threading accessory includes one or more pressure wheels configured to engage a portion of the belt passing between the rotating wheels and elastically deform the portion of the belt, thereby at least partially deforming and / or wrapping around the portion of the thread and latching the portion of the thread inwardly within the circumferential groove.

[0024] The threading accessory, in some embodiments, includes a press wall fixedly disposed between the rotating wheels facing the inner surface of the belt. The one or more press wheels can be configured to press a portion of the belt against the press wall, elastically deforming the portion of the belt. The press wall, in possible embodiments, includes a horizontal groove configured to receive the portion of the belt pressed by the one or more press wheels and facilitate elastic deformation of the portion of the belt and latching onto the thread. Optionally, but preferably in some embodiments, the one or more press wheels are fixedly connected to the press wall.

[0025] In some embodiments, the threading accessory includes at least one guide eyelet configured to guide the thread into or out of the circumferential groove of the belt. The belt may include a circumferential drive rail formed on an interior side thereof. The rotatable wheel may include a retention groove configured to receive the drive rail of the belt therein. Optionally, the at least one circumferential drive rail of the rotatable wheel has a gear-shaped inner surface. The circumferential drive rail of the belt may include a corresponding gear configured to mesh with the gear-shaped inner surface of the at least one circumferential drive rail of the rotatable wheel.

[0026] The belt, the rotating wheel, and the pressure wheel are arranged on one side of the support platform in possible embodiments. A transmission unit of the threading accessory can be mounted on another side of the support platform and mechanically coupled to at least one of the rotatable wheels passing therethrough. The transmission unit includes, in some embodiments, a gear system configured to receive an external rotational motion on a rotation axis substantially parallel to the threading axis of the threading device and to transmit the rotational motion to at least one of the rotatable wheels.

[0027] The threading accessory may include, for example, a handle connectable to the transmission unit. The belt, in some embodiments, has a tapered portion extending from the circumferential groove toward an edge of the belt and configured to facilitate deformation and latching of a thread retained in the circumferential groove.

[0028] Optionally, at least one of the rotatable wheels includes a gear. An inner surface of the belt may include a corresponding gear configured to mesh with the at least one gear of the rotatable wheel.

[0029] The threading accessory, in some embodiments, includes a tiltable thread receptacle configured to spool therein relative to an inner element thereof. The tiltable thread receptacle may be attached to the threading accessory by an axle. The tiltable thread receptacle is configured to rotate in opposite directions about the axle in response to winding and unwinding of thread therein. The tiltable thread receptacle may be a circular receptacle having a circular opening configured to allow thread to pass therethrough. In possible embodiments, the tiltable thread receptacle includes a closure disc member, a number of "U" shaped ribs extending from the closure disc member, and one or more rings attached to the number of "U" shaped ribs.

[0030] In another aspect, a method of threading is provided, the method including the steps of coupling an actuator to a transmission unit of a threading accessory, actuating the actuator to transmit rotational motion in a first rotational direction to rotate a push belt of the threading accessory, the push belt having a pushable thread retained in a circumferential groove thereof, and pressing a portion of the push belt to elastically deform and at least partially cover the pushable thread, thereby increasing friction / retention between the portion of the pushable thread and the circumferential groove of the push belt when the pushable thread is moved in a first axial direction relative to the push unit.

[0031] The method, in some embodiments, includes actuating an actuator to transmit rotational motion in a second rotational direction opposite the first rotational direction, thereby causing the push belt to move the propulsable sled in a second axial direction relative to the push unit. The method may further include winding or reeling a portion of the propulsable sled within the rotatable sled receptacle in response to actuation of the actuator. [Brief description of the drawings]

[0032] In order to better understand the subject matter disclosed herein and to illustrate how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which the features shown are intended to illustrate only some embodiments of the invention, unless otherwise expressly stated, and in which the same reference numerals have been used to indicate corresponding parts. [Figure 1] FIG. 1 illustrates a schematic of a handheld threading accessory according to some possible embodiments, FIG. 1 being a perspective view of the handheld threading accessory. [Diagram 2] FIG. 2 illustrates a schematic of a handheld threading accessory according to some possible embodiments, with FIG. 2 showing a side view of the handheld threading accessory in an actuated state (with a propellable thread) and an actuator device connectable thereto. [Diagram 3] FIG. 3 illustrates a schematic of a handheld threading accessory according to some possible embodiments, with FIG. 3 being a front view of the handheld threading accessory. [Figure 4] FIG. 4 is a schematic diagram of a handheld threading accessory without a thread / draw tape receptacle, and FIG. 4 is a front cross-sectional perspective view of the handheld threading accessory. [Diagram 5] FIG. 5 is a schematic diagram of a handheld threading accessory without a thread / draw tape receptacle, and FIG. 5 is a partially exploded perspective view of the handheld threading accessory. [Figure 6] Figures 6A-6E are schematic diagrams illustrating the operating states of a grooved belt and a propulsion unit utilizing the same according to some possible embodiments, where Figures 6A and 6B are perspective and cross-sectional perspective views of the grooved belt, respectively, Figure 6C is a cross-sectional view taken at the rear rotating wheel of the propulsion unit, Figure 6D is a cross-sectional view taken at the belt pressing gap of the propulsion unit, and Figure 6E is a top view of the grooved belt of the propulsion unit where the grooved band / belt is coupled to the rotating wheel. [Figure 7] FIG. 7 is a schematic diagram illustrating a gear-based propulsion unit configuration, according to some possible embodiments. [Figure 8] 8A and 8B are schematic top and side views, respectively, of a tiltable sled / draw tape container according to some possible embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Various embodiments of the present application are described below with reference to the drawings, which should be considered in all respects as illustrative only and not limiting in any way. In order to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification. The elements illustrated in the drawings are not necessarily to scale or in correct proportion, which is not critical. Instead, emphasis is placed on clearly explaining the principles of the invention so that those skilled in the art may understand those principles and make and use the invention.

[0034] The embodiments disclosed herein relate to a threading accessory for advancing / retracting a pushable sled through a concealed or unconcealed passageway, e.g., a conduit or tunnel, for installation of a cable / wire / conduit therein. The threading accessory generally comprises a tiltable thread / draw tape container having a pushable sled spooled therein, in some embodiments, a transmission unit configured to receive a rotational motion generated by an external actuator device about its axis of rotational motion, and a push unit connected to a transmission arm of the transmission unit, the transmission arm being substantially perpendicular to the axis of rotational motion of the transmission unit.

[0035] The propelling unit is configured to receive rotational motion from the transmission and propel a portion of the propellable sled from / to the sled / draw tape receptacle in a propelling plane substantially parallel to the axis of rotational motion of the transmission unit. Optionally, but preferably in some embodiments, the axis of rotational motion of the transmission unit and the propellable sled passing through the propelling unit extend along substantially parallel imaginary lines.

[0036] In some embodiments, the thread / draw tape container is hinged to a rear portion of the propulsion unit to adjustably adapt the tilt angle relative to the propulsion plane defined by the propulsion unit as the portion of the propulsable thread is propelled in and out of the thread / draw tape container. In this way, the thread / draw tape container can assume a certain tilt angle when rotated in a first direction about the spool axis as the portion of the propulsable thread is propelled therefrom by the propulsion unit, and a different tilt angle when rotated in a second (opposite) direction about the spool axis as the portion of the propulsable thread is propelled inward, with the tilt angle gradually changing as the portion of the propulsable thread is accumulated in or expelled from the thread / draw tape container. The adjustable tilt angle configuration of the thread / draw tape container minimizes the load on the propulsion unit.

[0037] In some embodiments, the propulsion unit includes two rotating wheels, at least one of which is mechanically coupled to receive rotational motion from the transmission unit, and a grooved band / belt is coupled / mounted on the rotating wheel disposed thereon, defining a thread-retaining side and a thread-free side of the propulsion unit. The grooved band / belt includes a circumferential groove (e.g., on the inside) configured to receive and retain a portion of the propulsible thread at the thread-retaining side of the propulsion unit. In this manner, rotational motion transmitted from the transmission unit to the propulsion unit causes rotation of at least one of the rotating wheels, which in turn causes rotation of the grooved band / belt, which in turn causes a portion of the propulsible thread retained in the circumferential groove at the thread-retaining side of the propulsion unit to be propelled into or out of the thread / draw tape container, which in turn causes the thread / draw tape container to rotate about its spool axis.

[0038] In some embodiments, the rotating wheels of the propulsion unit are configured to define a belt pressing zone therebetween on the sled retaining side of the propulsion unit. The belt pressing zone is configured to elastically deform a portion of the grooved band / belt to substantially wrap around a significant circumferential portion of the propulsible sled, thereby increasing the friction and holding force of the grooved band / belt on the propulsible sled and enhancing grip. In some embodiments, one or more rollers are attached to the belt pressing zone, which press the advanceable sled against a portion of the circumferential grooves of the grooved band / belt, elastically deforming a respective portion of the grooved band / belt to wrap around and thus grip the circumference of the advanceable sled.

[0039] In some embodiments, the grooved band / belt is a synchronous (timing) belt and the rotating wheels are gears configured to mesh therewith. Optionally, but in some embodiments preferably, the grooved band / belt includes an inner drive rail formed thereon. Thus, each rotating wheel of the propulsion unit may include a circumferential channel configured to receive and hold a portion of the drive rail of the grooved band / belt that rotates therewith. In some embodiments, only the inner drive rail of the grooved band / belt is provided with a synchronous / timing gear configured to mesh with a respective toothed / gear (or sprocket) surface formed in the circumferential channel of the rotating wheel.

[0040] To provide an overview of some exemplary features, process steps, and principles of the present invention, a draw tape threading example is shown and described below in schematic and diagrammatic form. Although such a draw tape threading application is shown as one example illustrating many features, processes, and principles that can be used for laying wires / cables in conduits / tunnels, it is also useful for other applications and many variations can be made. Thus, the present specification will proceed with reference to the illustrated embodiment, but it will be understood that once the principles are understood from the description, explanations, and drawings herein, the claimed invention can be practiced in a myriad of other ways. All such variations, and any other modifications that are obvious to those skilled in the art and useful for threading applications, may be suitably employed and are intended to fall within the scope of the present disclosure.

[0041] 1-3, a handheld threading accessory 10 is shown generally according to some possible embodiments. FIGS. 1 and 2 show the handheld threading accessory 10 in an unactuated state (without draw tape 22) and an actuated state (with draw tape 22), respectively. FIG. 3 is a front view of the handheld threading accessory 10. The threading accessory 10 is configured in some embodiments to be actuated / connected by a handheld actuator device 14 for driving / manipulating (i.e., pushing / pulling) the draw tape 22. The draw tape 22 can be provided as an elongated fiberglass cable, or a braided cable, or a stainless steel cable, for example.

[0042] The threading accessory 10 generally includes a transmission unit 13 configured to receive rotational motion from an actuator device 14, a tiltable sled receptacle 11, which in some embodiments includes a draw tape 22 wound therein, and a propulsion unit 12 configured to receive rotational motion from the transmission unit 13 to propel a portion of the draw tape 22 out of or into the sled receptacle 11. The sled receptacle 11 is pivotally coupled to a support platform 12p of the propulsion unit 12. In particular, the sled receptacle 11 may be rotatably coupled, for example by a pivot / hinge 11x, to a rear support 12i projecting upward from a rear edge of the support platform 12p to allow angular movement of the tiltable sled receptacle 11 about its tilt axis 11i. The tiltable sled receptacle 11 forms a circular housing configured to receive the draw tape 22, inside which the draw tape 22 is spooled / restrained.

[0043] The thread container 11 is configured to rotate in one direction about the spool axis 11r in response to the outward thrust (pulling out) of the draw tape 22 by the thrust unit 12, and to rotate in the opposite direction in response to the inward thrust (pulling in) of the draw tape 22 by the thrust unit 12. This allows a portion of the draw tape 22 wound in the thread container 11 to be released / pushed out to the distal side, or a portion of the draw tape 22 to be pulled proximally to be wound into the thread container 11.

[0044] The components of the propulsion unit 12 are coupled to the support platform 12p at its top and / or bottom surface. The transmission unit 13 comprises a transmission arm 13a configured to transfer rotational motion from the transmission unit 13 to the propulsion unit 12 and to mechanically couple the propulsion unit 12 to the handheld actuator device 14. Optionally, but preferably in some embodiments, the transmission arm 13a may extend vertically from the transmission unit 13 and be vertically coupled to the support platform 12p at its bottom surface.

[0045] As shown in FIG. 1 and FIG. 2, the transmission unit 13 includes a bearing shaft 13x arranged along its rotational motion axis 13i, a part of which protrudes outward from the transmission unit 13. The bearing shaft 13x is configured to couple the transmission unit 13 and the hand-held actuator 14 and receive a rotational motion therefrom, which is transmitted by the transmission unit 13 to the propelling unit 12 to push or pull the draw tape 22. In some embodiments, the bearing shaft 13x is rotatable in two opposite directions, clockwise and counterclockwise, according to a typical operating state of the hand-held actuator 14. Optionally, the bearing shaft 13x is connected to the hand-held actuator 14 by a coupling, but in some embodiments, it is directly connected to the hand-held actuator 14 using an adjustable drill head / chunk or the like.

[0046] Optionally, but preferably in some embodiments, the threading accessory 10 is provided with a handle 19 fixedly / removably connected to the body 13b of the transmission unit 13 and extending laterally therefrom. The propulsion unit 12 includes two spaced apart rotating wheels, a front drive wheel 16d and a rear driven wheel 16s, and a grooved propulsion belt 15 stretched between the wheels 16s and 16d. The propulsion unit 12, i.e. its drive wheel 16d, is actuated by rotational motion transmitted through a transmission arm 13a of the transmission unit 13. In this particular non-limiting example, the front / drive wheel 16d is mechanically coupled to the transmission unit 13 via a transmission shaft / axle (12d in FIG. 4) configured to transmit / relay the rotational motion received from the actuator 14 to the drive wheel 16d. Alternatively or additionally, the transmission unit 13 may be coupled to and rotate the rear wheel 16s.

[0047] Thus, in the illustrated embodiment, the front drive wheel 16d is configured to transmit rotational motion of the hand-held actuator 14 received via the transmission unit 13 to the grooved propulsion belt 15, which in turn transmits the rotational motion to the rear drive wheel 16d for rotation. The grooved propulsion belt 15 has an inner engagement side (15i in Figs. 6A, 6B) for mechanically coupling to the spaced apart rotating wheels 16s, 16d, and a grooved outer / retaining side (15t) having a central circumferential groove 15g (extending axially along the periphery of the belt 15). The grooved outer / retaining side (15r) of the grooved propulsion belt 15 is configured to receive and retain a portion of the draw tap 22 within a respective portion of its circumferential groove (15g).

[0048] 2, the support platform 12p may be implemented by a flat plate arranged to connect (e.g., perpendicularly) to the transmission arm 13a of the transmission unit 13. The support platform 12p extends rearward from an end side coupled to the transmission arm 13a, e.g., substantially parallel to the threading axis 22x of the handheld threading accessory 10. Optionally, but preferably in some embodiments, the rotational motion axis 13i of the transmission unit 13 is substantially parallel to the threading axis 22x.

[0049] The rotating wheels 16s and 16d and the grooved push bands / belts 15 mounted thereon are disposed on the support platform 12p to define a push plane along which the draw tape 22 is pushed inwardly or rearwardly. In this particular, non-limiting example, the push plane of the draw tape 22 is substantially parallel to the support platform 12p and also parallel to the axis of rotational motion 13i of the transmission unit 13. Optionally, but preferably in some embodiments, the portion of the draw tape 22 pushed by the rotating wheels 16s, 16d and the grooved bands / belts 15 coupled thereto is substantially parallel to the axis of rotational motion 13i of the transmission unit 13.

[0050] The threading accessory 10 may include a forward support 12u projecting upwardly from a forward portion of the support platform 12p. The forward support 12u includes a front guide eyelet 18u configured to guide a portion of the draw tape 22 advanced therethrough, and the rear support 12i includes a rear guide eyelet 18i configured to guide a portion of the draw tape 22 advanced therethrough. Optionally, and in some embodiments preferably, the rear guide eyelet 18i and the front guide eyelet 18u are aligned with the circumferential groove 15g (e.g., located at the same height relative to the support platform 12p). This arrangement of the rear guide eyelet 18i and the front guide eyelet 18u ensures that the portion of the draw tape 22 passing through the propulsion unit 12 remains substantially straight / linearly aligned during operation. This keeps the portion of the draw tape 22 passing through the propulsion unit 12 substantially parallel to the support platform 12p, significantly reducing / eliminating the resistance forces acting on the draw tape 22 and facilitating smooth movement of the portion of the draw tape 22 as it passes through the propulsion unit 12 and its guide eyelets 18i, 18u.

[0051] The rotating wheels 16d and 16s can be configured to define a belt pressing zone 16g in the gap formed therebetween, pressing and elastically deforming a portion of the grooved propulsion belt 15 passing therethrough to substantially wrap around each portion of the draw tape 22 held in the circumferential grooves 15g of the grooved propulsion belt 15. Optionally, and in some embodiments preferably, the propulsion unit 12 comprises one or more spaced rollers (also referred to herein as pressing wheels) 17a, 17b, ... located in the belt pressing zone 16g opposite the rotating wheels 16s and 16d and spaced apart from the rotating wheels 16s and 16d. In this non-limiting example, two rollers 17a and 17b are located in the belt pressing zone 16g and configured to press a portion of the draw tape 22 against the grooved propulsion belt 15.

[0052] In operation, the portion of the draw tape 22 passing through the propulsion unit 12 (the portion held in the circumferential groove 15g) is forced by the pair of spaced rollers 17a, 17b into a portion of the circumferential groove 15g of the grooved propulsion belt 15 so that the portion of the draw tape 22 is firmly held / captured therein. In this manner, the pressure exerted by the spaced rollers 17a, 17b on the portion of the draw tape 22 against the circumferential groove 15g of the grooved belt 15 from above creates an enhanced frictional and holding force between the respective portion of the draw tape 22 and the respective portion of the circumferential groove 15g. Thus, when the actuator 14 is actuated in one direction (e.g., clockwise), a portion of the draw tape 22 is pulled out of the thread container 11 and pushed distally by the propulsion unit 12, and when the actuator 14 is actuated in the opposite direction (e.g., counterclockwise), a portion of the draw tape 22 is pulled proximally by the propulsion unit 12 and sent to be wound into the thread container 11.

[0053] 4, the transmission unit 13 includes a gear system 13g configured in some embodiments to transmit / relay the rotational motion received from the actuator device 14 to the front drive wheels 16d according to a selected angular velocity transmission ratio between the rotational speed (input angular velocity) of the actuator device 14 and the rotational speed (output angular velocity) of the front drive wheels 16d. In some possible embodiments, such a transmission ratio is set to about 1:2 (output:input) to provide sufficient power to actuate the front drive wheels 16d.

[0054] 2 and 4, the gear system 13g can be mechanically coupled to the actuator device 14 via a bearing axis / shaft 13x, and receives and transmits the rotational motion of the actuator device (14) to the propulsion unit 12 via a transmission shaft / axis 12d passing through the transmission arm 13a. The transmission arm 13a is configured to transmit / relay the rotational motion to the front drive wheel 16d for rotating the front drive wheel 16d about the axis xl of the transmission shaft / axis 12d.

[0055] 4, the rear driven wheel 16s is coupled to a rear pivot rod / shaft 12s that is rotatable about axis x2 and is configured to rotate the rear driven wheel 16s in response to movement of the grooved belt 15 during operation. The rear pivot rod / shaft 12s is connected to a bearing 12e whose outer ring is fixedly mounted (e.g., by a bearing housing 12q) to the bottom of the support platform 12p and configured to rotate about its axis x2.

[0056] As best seen in Figure 5, rollers 17a and 17b are connected to support element 12w via respective rods / poles 12a and 12b (e.g. implemented by cam followers) and are rotatable about the axis of the respective rods / poles 12a and 12b. Rollers 17a, 17b are disposed below support element 12w via respective rods / poles 12a, 12b such that they are suspended at a fixed distance from support platform 12p.

[0057] The rollers 17a and 17b are configured to press (apply force) against the grooved belt 15 to induce elastic deformation of a portion of the grooved belt, as described below with reference to Figure 6D, such that the portions of the draw tape 22 are pressed against the grooved push belt 15 and tightly captured / maintained within the circumferential grooves 15g of the grooved push belt 15 by the enhanced frictional forces between the portions of the draw tape 22 and the circumferential grooves 15g, and by the pressure of the spaced apart rollers 17a, 17b pressing the portions of the draw tape against the circumferential grooves 15g of the grooved belt 15.

[0058] In operation, as the draw tape 22 is pushed and pulled through the propulsion unit 12, the rollers 17a and 17b interact with the portion of the draw tape 22 held within the circumferential groove 15g in the belt pressure gap 16g, thereby causing a responsive rotation of the rollers 17a and 17b to facilitate smooth movement (pushing and pulling) of the draw tape 22.

[0059] As best seen in FIG. 4, the support element 12w is coupled to a press wall 12f that is located in a belt pressing gap (16g) defined between the wheels 16s and 16d and spaced apart from each of the wheels 16s and 16d. The press wall 12f is connected to a region of the support platform 12p that is located between the wheels 16s and 16d. As shown in FIG. 5, in some embodiments, the press wall 12f includes a guide groove 28 that is positioned facing / opposite the rollers 17a and 17b. The guide groove 28 is configured in some embodiments to receive a portion of a drive rail (15t in FIG. 6B) formed on the inside of the grooved belt 15 and guide the grooved belt 15 as it passes therethrough.

[0060] The press wall 12f is configured in some embodiments to provide a reaction force to the grooved belt 15. In this example, the rollers 17a, 17b press against the draw tape 22 and exert a radial force against the press wall 12f, forcing a portion of the draw tape 22 into the circumferential groove 15g of the grooved belt 15, compressing / deforming the portions of the grooved belt 15 against the press wall 12f and substantially overlaying the draw tape 22 and keeping it captured / held within the circumferential groove 15g.

[0061] The guide groove 28 can be configured to facilitate deformation of the grooved belt 15 when the grooved belt 15 is pressed against the press wall 12f by the rollers 17a, 17b and a part of the circumferential groove 15g is pressed against the guide groove 28 with the corresponding part of the draw tape 22 included inside. In this way, the upper and lower parts of the part of the circumferential groove 15g pressed into the guide groove 28 are caught by the part of the draw tape 22 and tightly gripped.

[0062] As shown in Figure 5, each rotatable wheel 16s, 16d is formed with a retaining groove / channel 23 that extends circumferentially about the wheel 16s, 16d. Each retaining channel 23 extends around the circumference of the respective rotatable wheel and is configured to receive therein a drive rail (15t in Figure 6B) of the grooved belt 15. The retaining channels 23 are aligned with the guide grooves 28 in the press wall 12f, i.e., flush with the support platform 12p, and define a path of travel for the drive rail (15t in Figure 6B) within the propulsion unit 12.

[0063] 6A and 6B, a grooved belt 15 is shown diagrammatically according to some possible embodiments. The grooved belt 15 has an inner engagement side / surface 15i having a drive rail 15t extending radially / inwardly therefrom along an inner circumference of the inner engagement side 15i. The drive rail 15t is configured to movably couple the grooved belt 15 to the spaced apart wheels 16s and 16d such that the drive rail 15t is received within and retained within the retaining grooves 23 of the wheels 16s and 16d as the wheels 16s and 16d rotate about their respective axes (x2 and xl). The grooved belt 15 has a grooved outer surface 15r having a circumferential groove 15g formed on an opposite side to the drive rail 15t and extending axially along the circumference of the belt 15. The grooved outer surface 15 is configured to receive a portion of the draw tape 22 inside each portion of the circumferential groove 15g, e.g., having a width W of 3 to 12, optionally about 3.5 millimeters. The width Y of the grooved belt 15 may typically range from 16 to 50 millimeters, optionally about 30 millimeters. The width E of the drive rail 15t may typically range from 3 to 10 millimeters.

[0064] As shown in FIG. 6B, the grooved belt 15 has a lower belt portion 15w and an upper belt portion 15u connected to each other via a drive rail 15t, and a circumferential groove 15g is disposed therebetween. The lower belt portion 15w and the upper belt portion 15u have predetermined tapers that define a taper angle Θ (e.g., about 8°-12°, optionally about 10°) that defines relatively narrow ends at the ends of the lower belt portion 15w and the upper belt portion 15u. The reduced thickness Z of the grooved belt 15 at both ends thereof can generally be in the range of 3-6 millimeters, and the thickness A at the relatively wide portions (central regions of the grooved bands) of the lower belt portion 15w and the upper belt portion 15u can generally be in the range of 5-10 millimeters, optionally about 5 millimeters.

[0065] 6C and 6D, cross-sectional views of the propulsion unit 12 taken along lines KK and JJ in FIG. 6E, respectively. FIG. 6E is a top view of the propulsion unit 12, showing the (dashed-dotted) lines KK and JJ of the cross-sections in FIG. 6C and 6D, respectively. As best shown in FIG. 6C, in some possible embodiments, the lower belt portion 15w and the upper belt portion 15u each have a respective retaining shoulder (step) 15s that extends downward / upward a distance R (e.g., about 2-5 millimeters, optionally about 2 millimeters) from the respective edge of the circumferential groove 15g, i.e., the surface of the retaining shoulder / step 15s is substantially parallel to the surface of the inner engagement surface 15i of the grooved belt 15.

[0066] The tapered portions of the grooved belt 15 extend from the respective shoulders 15s to the upper and lower ends of the grooved belt 15. The retention shoulders 15s define / constitute deformable regions 15p of the grooved belt 15 configured to capture / overlay the draw tape 22 retained within the circumferential groove 15g. More specifically, as shown in FIG. 6D, in operation, in response to pressure / force applied to a central region of the grooved belt 15 passing within the belt pressing zone 16g, the shoulders 15s of the lower belt portion 15w and the shoulders 15s of the upper belt portion 15u elastically deform toward each other, thereby at least partially closing the portion of the circumferential groove 15g within the belt pressing zone 15g and capturing / retaining the respective portions of the draw tape 22 within the circumferential groove 15g.

[0067] The cross-section (KK) of Fig. 6C shows the rear driven wheel 16s with the grooved belt 15 wrapped around it and the draw tape 22 held in the circumferential groove 15g before entering the belt pressing zone 16g, but with the shoulder 15s of the grooved belt 15 undeformed. The grooved belt 15 is also connected to the wheels 16s and 16d (only the wheel 16s is shown in this figure) such that the drive rail 15t is located in their retaining grooves 23. The diameter B of each wheel 16s, 16d is, for example, typically between 40 and 100 mm, optionally about 40 mm, and the width G of the retaining channel 23 is, for example, typically between 5 and 10 mm, optionally about 5 mm.

[0068] Figure 6D is a cross-sectional view of the propulsion unit 12 taken along the section line JJ of the belt pressing zone 16g. In operation, the rollers 17a and 17b (only roller 17b, i.e., cam follower, is shown in Figure 6D) abut the deformable region 15p of the grooved belt 15 and exert a pressure / force on the retaining shoulder 15s. The pressure / force exerted by the rollers 17a and 17b causes the retaining shoulders 15s to elastically deform towards each other on the portion of the draw tape captured therebetween, at least partially closing the gap / space of the groove 15g such that the deformed portion of the grooved belt 15 overhangs the portion of the draw tape 22 retained in the circumferential groove 15g.

[0069] Referring to FIG. 7, a possible embodiment of the propulsion unit 12 is shown in which the wheels 16s and 16d are configured as gears. In this possible embodiment, the inner engagement surface 15i of the grooved belt 15 can be configured to include timing teeth (not shown) to form a synchronous (timing) belt configured to engage with the gears (16s and 16d). In a possible embodiment, only the drive rail 15t of the grooved belt 15 includes timing teeth (toothed inner circumference - not shown) configured to mesh with the respective toothed / gear surfaces (15q in FIG. 6C) formed on the inside of the circumferential channel 23 of the rotating wheels 16s, 16d. In another possible embodiment, both the inner engagement surface 15i of the grooved belt 15 and the drive rail 15t include timing teeth (gear-like inner circumference - not shown) configured to mesh with the respective toothed sprockets (15q) formed on the inside of the circumferential channel 23 of the rotating wheels 16s, 16d.

[0070] 8A and 8B, top and side views, respectively, of a tiltable thread container 11 according to some possible embodiments are shown. The tiltable thread container 11 comprises, at its upper side, a closure disk 11p connected to the axis / shaft 11q of the thread container 11. The tiltable thread container 11 also comprises a plurality of spaced apart U-shaped arches / ribs 11r extending radially from the closure disk 11p and curving downwardly inwardly to define a spool space therein for the draw tape 22. The plurality of spaced apart U-shaped arches / ribs 11r are connected to each other by upper and lower rings 11a and 11b, and to an inner ring 11c connecting the free ends of the U-shaped arches / ribs 11r to define an annular opening through which a portion of the draw tape 22 is propelled into / out of the thread container 11.

[0071] In a possible embodiment, the angled sled container 11 is fixedly adjusted upon connection to the support platform 12p (e.g., during manufacture / assembly) or prior to use by an operator and maintains a fixed angle during operation. Alternatively, the angle of inclination of the sled container 11 may be a fixed angle that cannot be changed.

[0072] Also, throughout this disclosure, where a process or method is shown or described, it is understood that the steps of the method may be performed in any order or simultaneously, unless it is clear from the context that one step is dependent on another step being performed first. Also, it is noted that terms such as primary, secondary, first, second, ... may be used to refer to particular elements disclosed herein without limitation, but rather to distinguish the disclosed elements. Relative terms such as "lower", "upper", "horizontal", "vertical", "up", "lower", "upper", "lower", "top", "bottom", and derivatives thereof (e.g., "horizontal", "downward", "upward", etc.) and similar adjectives relating to the orientation of the described elements / components are intended to indicate the manner in which the figures are arranged on the paper, and are not intended to limit the orientation in which these elements / components may be used in practical application.

[0073] As described above and shown in the associated figures, the present disclosure provides a handheld threading accessory. Although specific embodiments of the present invention have been described, the present invention is not limited thereto, and those skilled in the art will appreciate that modifications are possible, especially in light of the teachings set forth above. For example, the threading accessory need not necessarily be implemented as a handheld unit (i.e., it may be stationary or portable on wheels), but may include an integrally assembled actuator device. Furthermore, the disclosed threading accessory may be utilized for threading any elastically deformable thread (e.g., cable, wire, pipe / conduit, etc.) for any suitable purpose (e.g., unblocking a pipe / tunnel, monitoring and / or measuring such pipe / tunnel, etc.). Thus, as will be appreciated by those skilled in the art, the present invention may be implemented in a wide variety of ways, employing one or more of the techniques described above, without departing from the scope of the claims.

Claims

1. 1. A threading accessory comprising: a belt; two rotatable wheels configured to rotate the belt, the belt having a circumferential groove formed in an outer surface thereof configured to receive and retain a portion of a thread therein; and one or more pressure wheels configured to engage a portion of the belt passing between the rotating wheels and elastically deform the portion of the belt, thereby at least partially over and latching the portion of the thread within the circumferential groove.

2. 2. The threading accessory of claim 1, further comprising a press wall fixedly disposed between the rotating wheels facing an inner surface of the belt, the one or more pressure wheels being configured to press a portion of the belt in contact with the press wall to elastically deform the portion of the belt.

3. 3. The threading accessory of claim 2, wherein the press wall includes a horizontal groove configured to receive a portion of a belt pressed by the one or more pressure wheels and facilitate elastic deformation of the portion of the belt and latching of the thread.

4. The threading accessory of claim 3 , wherein the one or more pressure wheels are fixedly connected to the press wall.

5. Threading accessory according to any of the preceding claims, comprising one or more guide eyelets configured to guide the thread into and out of a circumferential groove of the belt.

6. 6. The threading accessory of claim 1, wherein the belt has a circumferential drive rail formed on an inner side thereof, and the rotatable wheel has a retention groove configured to receive the drive rail therein.

7. The threading accessory of claim 6 , wherein one or more circumferential drive rails of the rotatable wheels have a gear-shaped inner surface.

8. 8. The threading accessory of claim 7, wherein a circumferential drive rail of the belt includes a gear configured to mesh with a gear-like inner surface of a circumferential drive rail of one or more of the rotatable wheels.

9. The threading accessory according to any one of claims 1 to 8, wherein the belt, the rotatable wheel and the pressure wheel are arranged on one side of a support platform, and a transmission unit of the threading accessory is attached to the other side of the support platform.

10. 10. The threading accessory of claim 9, wherein the transmission unit comprises a gear system configured to receive an external rotational motion about an axis of rotation substantially parallel to a threading axis of the threading device and to transmit the rotational motion to one or more of the rotatable wheels.

11. The threading accessory of claim 10, comprising a handle connectable to the transmission unit.

12. 12. The threading accessory of claim 1, wherein the belt has a tapered portion extending from the circumferential groove toward an edge of the belt and configured to facilitate deformation and latching onto the thread.

13. The threading accessory according to any one of the preceding claims, wherein one or more of the rotatable wheels comprises a gear.

14. The threading accessory of claim 13 , wherein an inner surface of the belt includes gears configured to mesh with one or more gears of the rotatable wheel.

15. Threading accessory according to any one of claims 1 to 14, comprising a tiltable thread container configured to wind the thread therein relative to the inner element.

16. 16. The threading accessory of claim 15, wherein the tiltable thread receptacle is attached to the threading accessory by an axis, and the tiltable thread receptacle is configured to rotate in opposite directions about the axis in response to winding the thread therein and unwinding the thread.

17. The threading accessory of claim 16, wherein the tiltable thread receptacle is a circular receptacle having a circular opening configured to pass the thread therethrough.

18. 18. The threading accessory of claim 16 or 17, wherein the tiltable thread receptacle comprises a closure disc member, a plurality of "U" shaped ribs extending from the closure disc member, and one or more rings attached to the plurality of "U" shaped ribs.

19. 1. A method of threading a thread, comprising the steps of: connecting an actuator to a transmission unit of a threading accessory; and actuating the actuator to transmit rotational motion in a first rotational direction to rotate a push belt of the threading accessory, the push belt holding a pushable thread in a circumferential groove thereof; and pressing a portion of the push belt to elastically deform and at least partially cover the pushable thread, thereby increasing friction / retention between the portion of the pushable thread and the circumferential groove of the push belt when the pushable thread is moved in a first axial direction relative to the push unit.

20. 20. The method of claim 19, comprising actuating the actuator to transmit rotational motion in a second rotational direction opposite the first rotational direction, thereby causing the push belt to move the propulsable sled in a second axial direction relative to the propulsion unit.

21. 21. The method of claim 19 or 20, comprising winding or unwinding a portion of the propellable thread into a rotatable thread receptacle in response to actuation of the actuator.

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