Heavy duty cable puller having overload indicator

Abstract

The cable puller uses a compound handle to create great leverage in order to generate a large pulling force with a minimal amount of force applied by the operator. The pulling force can be used for heavy lifting applications. The cable puller could be used to hoist motors, shafts, gears, automobile engines, construction material, machinery and other heavy objects. The cable puller could also be used in the demolition of building structures, the erection of buildings and towers, straightening collision damage, opening railroad car doors, securing tent structures, stretching fence and wire, and tightening conveyor belts. In one embodiment, the handle creates a lever ratio of 65:1. In this instance, 8,000 lbs. can be lifted with an exertion of 123 lbs. of force by the operator. The compound handle is formed by a driven member that engages and rotates the ratchet wheel. A cable is taken up by the wheel in order to move objects. The driven member is connected to a driving member by a connection member. The driving member has a handle grasped by the user and pivoted in order to cause the driving motion of the ratchet wheel.

Description

FIELD OF THE INVENTION

[0002] The invention relates to cable pullers.

BACKGROUND OF THE INVENTION

[0003] Cable pullers are used to wind a cable about a drum. The cable end can be attached to an item in order to lift the item or the puller can be used to stretch the cable. It is known in the art to have cable pullers that are powered or operated by hand. To gain leverage in order to lift or pull heavy objects, on the order of three to four tons, existing cable pullers have a straight line telescoping handle. This arrangement creates several problems including: the operator having a difficult time guiding the load due to the distance of the handle from the drum; the impracticality of operating the device in a confined space; and the inherent safety risk of the lever inadvertently striking the operator.

[0004] U.S. Pat. No. 4,199,134 (Kerber et al) discloses a portable winch having a ratchet wheel and an actuator. The actuator carries a pawl and a grip. The actuator member is connected at the center of the ratchet wheel so that rotation of the actuation member causes the pawl to engage the ratchet wheel.

[0005] U.S. Pat. No. 4,723,757 (Steinman et al) discloses a portable winch having a ratchet wheel and an actuation member 16 provided with a grip. This actuation member is attached at the center of the ratchet wheel.

[0006] U.S. Pat. No. 2,658,723 (Coffing) discloses a hoist having a ratchet wheel and an actuation member carrying a pawl. A linkage connected to the center wheel spaces the actuation member from the wheel.

[0007] U.S. Pat. No. 1,823,760 (Pierce) discloses a jack having a ratchet wheel and an actuation member having a pawl. A handle connects to the end of the actuation member.

[0008] There is a need in the art for a cable puller having a handle providing leverage to create a large pulling force with a minimal amount of force applied by the operator.

[0009] It is another object of the invention to provide a cable puller having a compound handle that increases leverage and magnifies the force applied by the operator.

[0010] It is another object of the invention to provide a portable, compact cable puller that can be easily transported and used to generate a large pulling force.

[0011] It is another object of the invention to provide a reliable cable puller that is both easy to use and inexpensive to manufacture.

[0012] It is still another object of the invention to provide a cable puller having an overload indicator.

[0013] These and other objects of the invention will be become apparent to one of ordinary skill in the art after reviewing the disclosure of the invention.

SUMMARY OF THE INVENTION

[0014] The cable puller, embodying the present invention, uses a compound handle to create great leverage in order to generate a large pulling force with a minimal amount of force applied by the operator. The pulling force can be used for such applications as lifting heavy objects. The cable puller could be used to hoist motors, shafts, gears, automobile engines, construction material, machinery and other heavy objects. The cable puller could also be used in the demolition of building structures, the erection of buildings and towers, straightening collision damage, opening railroad car doors, securing tent structures, stretching fence and wire, and tightening conveyor belts. In one embodiment, the handle creates a lever ratio of 65:1. In this instance, four tons can be lifted with an exertion of 123 lbs. of force by the operator.

[0015] The compound action of the handle is similar to the low gear on a bicycle in that it reduces the operator's effort but causes the load to ascend and descend at a slower rate. The slower movement of the load reduces the risk to the operator as it is easier to control.

[0016] The compound handle is formed by a driven member that engages and rotates the ratchet wheel. A cable is taken up by the wheel in order to move objects. The driven member is connected to a driving member by a connection member. The driving member has a handle grasped by the user and pivoted in order to cause the driving motion of the ratchet wheel.

[0017] The cable puller is provided with an overload indicator signaling when the load on the cable puller is beyond a safe level. An indicator shows a green dot when the load is safe which turns to a red dot when the cable puller has reached an overload condition.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG. 1 is a plan view of the cable puller;

[0019] FIG. 2 is a plan view of the cable puller with the cables and hooks removed;

[0020] FIG. 3 is a plan view of the frame of the cable puller;

[0021] FIG. 4 a is a side view of the ratchet wheel;

[0022] FIG. 4 b is a view from line b-b of FIG. 4a;

[0023] FIG. 5 is a plan view of the cable puller having the overload indicator;

[0024] FIG. 6 is a side view of the overload indicator; and

[0025] FIG. 7 is a perspective view of the overload indicator with the sleeve shown in phantom.

DETAILED DESCRIPTION OF THE INVENTION

[0026] The cable puller 10 is depicted in FIG. 1. The frame 12 serves as the connection point for the parts that enable the cable puller to function. Connected to and extending from both sides of the frame 12 is a bottom member 38. Attached to one side of the bottom member 38 is a hook 35. A cable 33 is attached to the ratchet wheel, not shown, and extends through a cable guide 31 attached to the bottom member 38 and around a second hook/pulley assembly 32. The cable terminates in a third hook 37 which is releaseably attached to the bottom member 38.

[0027] Rotation of the ratchet wheel is accomplished by manipulation of a handle 60. With rotation of the ratchet wheel, the cable 33 is wrapped about the ratchet wheel and decreases the distance between the first hook 35 and second hook 32. With the shortening of the effective length of the cable, force is applied to the objects attached to the first hook 35 and second hook 32.

[0028] The cable puller having the cables and hooks removed can be seen in FIG. 2. As is depicted in FIG. 2, the frame 12 serves as an attachment point for the various parts that effectuate the operation of the device. The bottom member 38 is connected to and extends from both sides of the frame 12. The bottom member serves as an attachment point for the hooks that will be used in the pulling operation. The cable is wrapped around a ratchet wheel 20, shown in partial phantom. When rotated, cable is wrapped about the ratchet wheel 20 to shorten the available length of cable. In the reverse operation of lowering an object, the drum rotates in a reverse direction and cable is let out.

[0029] The structure of the compound handle 60 can clearly be seen in this figure. The driving member 62 connects to a top point of the frame 12 at a pivot point 63. The driving member is grasped and rotated about the pivot point 63. A connecting member 67 is rotatably connected at junction 69 to the driving member to allow for relative rotation between the driving member 62 and the connecting member 67. The opposite end of the connecting member 67 is rotatably connected at a junction 68 to a driven member 65. Junction 68 allows relative rotation between the driven member 65 and connecting member 67. The connecting member transfers the rotational motion of the driving member 62 to the driven member 65.

[0030] The driven member 65 is pivotally connected to the frame at pivot point 66. This pivot point 66 is coaxial with the center of the ratchet wheel 20. A ratchet pawl 42 is attached to the driven member 65 at a point spaced from the pivot point 66 so that the end of the ratchet pawl 42 engages the teeth of the ratchet wheel 20. When the driven member rotates about pivot point 66, the ratchet pawl engages and drives the ratchet wheel 20. A stop pawl 44 is connected to the bottom member 38. Its function is to prevent counter rotation of the ratchet wheel 20.

[0031] FIG. 3 shows the frame without the attachment of any of the other pieces of the device. As illustrated, the housing has several apertures for the attachment of pieces of the device. Some attachment points allow pivotal rotation, as previously discussed.

[0032] FIG. 4 a and FIG. 4b show the side and end view of the ratchet wheel respectively. The ratchet wheel is a conventional design having a drum for holding the cable. Ratchet teeth are provided on one side of the ratchet wheel. In FIG. 4b, only a few teeth are depicted, for clarity. The teeth are engaged by the ratchet pawl to rotate the drum. The ratchet drum does not differ in structure from ratchet wheels used in the existing art.

[0033] The device allows the exertion of a large amount of force on an object with minimal force applied by an operator. The compound handle design allows for a great amount of leverage, while in a compact size allowing for easier, safer use.

[0034] FIG. 5 shows the cable puller provided with an overload indicator. The overload indicator forms part of the connecting member 167. As seen in FIG. 6, the overload indicator 167 is formed by two metal bars, a first member 172 and a second member 174. The two metal bars are enveloped by a sleeve 176. The sleeve maintains the first member 172 and second member 174 is a co-linear relationship. The sleeve has an indicator aperture 177 displaying a green color when the applied load is less than the capacity of the cable puller. When the applied load reaches capacity, the indicator aperture displays a red color. The change of color from green to red relies upon relative movement between the sleeve and first member 172, as will be explained hereinafter.

[0035] The structure of the overload indicator is best seen in FIG. 7. The first member 172 and second member 174 are maintained in a spaced relation by a spring 178. The spring is retained in detents of the first and second member. Under normal conditions, the apertures reveals a portion of the first member that is green. When a load is applied to the cable puller, the spring is compressed and the first member 172 and second member 174 move toward one another. When the applied load reaches capacity, the first member 172 has moved in relation to the sleeve 176 a distance great enough to reveal a red color on the first member through the indicator aperture 177. At capacity, the first member 172 and second member 174 abut and cause an z audible click to signal the operator that the cable puller has reached capacity. The audible click occurs at the same time that the indicator shows red. The operator will be able to lower or release the load safely and reset the unit. This greatly increases the safety when using the cable puller.

[0036] While the invention has been described with respect to preferred embodiment, variations, modifications would be apparent to one of ordinary skill in the art without departing from the spirit of the invention.

Claims

1. A cable puller, comprising: a frame, a ratchet wheel connected to said frame, a handle for rotating said ratchet wheel, said handle comprising: a driven member, said driven member pivotally connected to said frame; a ratchet pawl attached to said driving member and engaging said ratchet wheel; a driving member pivotally attached to said frame; and a connecting member pivotally connected to said driving member and said driven member.

2. The cable puller of claim 1, further comprising: a bottom member, and a stop pawl attached to said bottom member for preventing counter rotation of said ratchet wheel.

3. The cable puller of claim 1, wherein said connecting member is connected to a midpoint of said driving member and an end of said driven member.

4. The cable puller of claim 1, wherein said cable puller has a lever ratio of 65:1.

5. The cable puller of claim 1, wherein said connecting member has an overload indicator.

6. The cable puller of claim 5, wherein said overload indicator comprises: a first member having a first end and a second end, said first member first end connected to said driving member; a second member having a first end and a second end, said second member first end connected to said driver member; said first member and said second member biased apart; a sleeve enveloping said second ends of said first member and said second member, said sleeve having a visual indicator.

7. The cable puller of claim 6, wherein said visual indicator is an aperture in said sleeve.

8. The cable puller of claim 7, wherein said aperture reveals a first color under normal conditions and a second color under overload conditions.

9. The cable puller of claim 6, wherein said first member and second member are biased apart by a spring.

10. An overload indicator for measuring an applied force, comprising: a first bar; a first member having a first end and a second end, said first member connected to and extending from said first bar; a second bar; a second member having a first end and a second end, said second member connected to and extending from said second bar; said second ends of said first and second member being biased apart; a sleeve, said sleeve enveloping said second ends of said first and second members, said sleeve having a visual indicator.

11. The overload indicator of claim 10, wherein said visual indicator is an aperture in said sleeve.

12. The overload indicator of claim 10, wherein said aperture reveals a first color under normal conditions and a second color under overload conditions.

13. The overload indicator of claim 10, wherein said first member and second member are biased apart by a spring.