CROSS-REFERENCE TO RELATED APPLICATIONS
Applicant claims priority under the Paris Convention for the Protection of Industrial Property to Chinese Patent Application No. ______ filed in the People's Republic of China on ______, the disclosure of which is herewith incorporated by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates to mechanical technologies and in particular to a tool for manipulating loads.
BACKGROUND
When pulling heavy items, when towing vehicles or when setting up a tent, a come-along is often useful. A come-along is desirable in these situations because it is a simple mechanism, is easy to transport and provides great pulling force.
A conventional come-along 50 is shown in FIGS. 1-5. FIG. 1 is a side partial-cutaway view of a conventional come-along 50. FIG. 2 is a front view of the conventional come-along 50. The come-along 50 has a main body 5 with a first hook 52 attached at a first end of the main body 5. The main body 5 includes an axial tube 1. The main body 5 includes a rope 3 or cable wound around the axial tube 1. A second hook 7 is connected to an end of the rope 3.
In operation, the second hook 7 is hooked to the load to be pulled such as a heavy item or a vehicle. The tightening and release of the second hook 7 is realized through the winding of the rope 3 to the axial tube 1. This operation often results in a messy or loose winding of the rope 3, as the rope 3 will typically be wound around the axial tube 1 in more than two layers. Once the rope 3 is pulled, it is possible that the outermost layer of the rope 3 coiled on the axial tube 1 will be tightened. When the outermost layer of the rope 3 tightens, it typically sinks under windings of the rope 3 of the inner layers. This creates difficulty in pulling the rope out of the layers of the loosely wound ropes, even resulting in breakage of the rope if the rope is pulled too hard.
FIG. 3 shows a top view of the axial tube 1 with a winding of rope 3 of the conventional come-along of FIG. 1. One end of the rope 3 is inserted and clamped into a positioning hole on the axial tube 1 to achieve secure connection. The inner end of the rope 3 is typically bent about 90 degrees coming out from the positioning hole in order to be wound onto the axial tube 1. Due to the fact that the rope is typically made of steel and accordingly possesses certain rigidity, there exists a perturbation 16, or bulge, around the bend. Moreover, this perturbation is generally telegraphed through subsequent layers of rope that are wound around the axial tube 1. This causes an off-roundness of the rope winding that results in an unevenness of the tightness of the rope. As a consequence, the ejection force of the rope will become uneven or the rope might get stuck on the axial tube which diminishes the usefulness of the come-along.
FIG. 4 is a side view of the conventional axial tube 1 with windings of the rope 3 and a clamp 60. FIG. 5 is a side view of the conventional axial tube 1 without rope 3. As shown in FIG. 4, the inner end of the rope 3 is clamped to the positioning hole that is on the axial tube 1. This is not a very secure fixturing method, as the rope is often pulled off the axial tube 1 after all the windings have been released. This affects the normal usage of the come-along and creates a certain risk of danger because the rope being pulled off the axial tube also results in a release of the load connected to the come-along.
For the foregoing reasons, there is a need for an improved come-along.
SUMMARY
The present invention is directed to a rope-winding mechanism for a come-along. The rope winding mechanism reduces the bulge present on the axial tube in conventional come-alongs. The rope winding mechanism of the present invention also provides a more secure attachment to the axial tube. The invention is realized through the following features: in the rope winding mechanism for the come-along, a concave, helical slot is devised. The helical slot extends from the positioning hole all along the surface of the axial tube in the orientation of the rope winding direction. Viewed in cross section, the distance between the adjacent slots of the axial tube is the same as the diameter of the rope or somewhat larger. This mechanism enables the rope to fall into the slots in an orderly fashion to make the rope arrangement neat and tight, thus reducing the possibility of an outer layer rope falling into inner layers of rope.
A rope securing mechanism is located on the axial tube used for winding the rope. The axial tube includes a positioning hole. An inner end of the rope is embedded into the positioning hole. This design possesses the following features: the aforementioned positioning hole is located on an outer curved surface of a Y-shaped axial tube cross section. The positioning hole opening is located on a side surface of the Y-shaped curved-surface, which enables the rope exiting the positioning hole to be wound around the axial tube in an almost-tangent angle to the axial tube. In addition, the rope is situated into the helical slots, which eliminates the perturbation, or bulge, of the rope, resulting in an even force on the rope during use.
In the aforementioned securing mechanism for the come-along, an installation hole is connected to the positioning hole located on the axial tube. The dimension of the installation hole is greater than that of the positioning hole. A seal head is also on the end of the rope and the seal head is held in the positioning hole. The rope end with the seal head can go through the installation hole, but not the positioning hole. Thus the inner end of the rope can go through the installation hole and be inserted into the axial tube, and then slid into the positioning hole for a secure fixturing between the rope and the axial tube.
In the aforementioned rope securing mechanism for the come-along, a stopper plate is located between the installation and positioning holes, which is part of the axial tube. When the inner end of the rope is inserted into the installation hole and then slid into the positioning hole, the stopper plate is bent to allow the passing of the rope. The stopper plate is then pressed down after the installation of the rope is complete to prevent the rope from sliding back to the installation hole.
The aforementioned rope securing mechanism for the come-along has the following features: a rope securing latch is situated on the axial tube that will be securely connected onto the axial tube. The rope securing latch has an “n” shape and has a press-latch part adapted to be pressed around the rope that has already been wound several loops on the axial tube.
In the aforementioned rope securing mechanism, the cross-section of the press-latch is in an “n” shape. Typically, the press-latch is pressed into the axial tube on the rope that has already been wound with 1-8 loops around the axial tube.
In the aforementioned rope securing mechanism for the come-along, the stated rope securing latch is connected to the rectangular slots on the axial tube through the elasticity of the triangular latch and the openings under the latch.
Through the rope securing latch to secure the several loops of the rope onto the axial tube, the normal usage of the come-along can be ensured as the rope securing latch prevents the complete unwinding of the rope. When the rope is pulled to the securing latch, the rope is unable to pull any further. Due to the fact that the rope securing latch is located several loops from the rope inner end, the rope has a greater winding force. The fixturing between the rope and the axial tube makes it difficult for the rope to detach from the axial tube, thus improving the safety and reliability of the come-along.
The present invention together with the above and other advantages may best be understood from the following detailed description of the embodiments of the invention illustrated in the drawings, wherein:
DRAWINGS
FIG. 1 is a side partial cut-away view of a conventional come-along;
FIG. 2 is a front view of the conventional come-along of FIG. 1;
FIG. 3 is a top view of a conventional axial tube of the come-along of FIGS. 1 and 2;
FIG. 4 is a side view of the conventional axial tube of FIG. 3 including windings of rope;
FIG. 5 is a side view of the conventional axial tube of FIG. 3 without windings of rope;
FIG. 6 is a side partial cut-away view of a come-along according to principles of the invention;
FIG. 7 is a front view of the come-along of FIG. 6;
FIG. 8 is a cross-section view at A-A of windings of rope on the axial tube of FIG. 7;
FIG. 9 is a front view of the rope securing latch of the present invention;
FIG. 10 is a side view of the rope securing latch of the present invention;
FIG. 11 is a top view of the axial tube of the present invention;
FIG. 12 is a side view of the axial tube of the present invention;
FIG. 13 shows the stopper plate of the present invention in a pressed-down state;
FIG. 14 shows the stopper plate of the present invention in a bent state;
FIG. 15 is a side cross-section view of the rope securing latch of the present invention in operation;
FIG. 16 is a top view of the axial tube of the present invention including an A-shaped curvature; and
FIG. 17 is a side view of the axial tube including a rope securing mechanism of the present invention.
DETAILED DESCRIPTION
A come-along includes an improved rope-winding mechanism and rope-securing mechanism. The rope-winding mechanism enables the rope to be wound and unwound smoothly during operation of the come-along. The rope-securing mechanism also improves the winding of the rope of the come-along and prevents the rope from pulling off the come-along.
FIG. 6 is a side partial cut-away view of a come-along according to principles of the invention. FIG. 7 is a front view of the come-along according to principles of the invention. The come-along 90 includes a main body 105, a handle 106, a rope 103, a first hook 107 and a second hook 152. The axial tube 101 and ratchet 108 are on the main body 105. The axial tube 101 and ratchet 108 are securely connected together. Turning the handle 106 turns the ratchet 108, thereby winding the rope 103 onto the axial tube 101.
When using the come-along 90, the rope 103 is pulled out and the first hook 107 is hooked onto a heavy item or to a vehicle. The handle 106 is then turned to tighten the rope 103 winding on the axial tube 101. According to principles of the invention, the axial tube includes concave helical slots 104.
FIGS. 8-17 illustrate a rope winding mechanism and rope-securing mechanism of the present invention. FIG. 8 is a cross-section view at A-A of windings of rope on the axial tube including a rope winding mechanism according to principles of the invention. FIG. 9 is a front view of a rope securing latch 102 of the present invention. FIG. 10 is a side view of the rope securing latch 102 of the present invention including a pressing portion 113 that, in operation, presses on the rope 103. FIG. 111 is a top view of the axial tube 101 of the present invention. FIG. 12 is a side view of the axial tube of the present invention. FIG. 13 is an illustration of the stopper plate in a pressed-down state and FIG. 14 is an illustration of the stopper plate in a bent state according to principles of the invention. FIG. 15 is a side cross-section view of the rope securing latch in operation according to principles of the invention. FIG. 16 is a top view of the axial tube 101 including an A-shaped curvature. FIG. 17 is a side view of the axial tube including a rope securing mechanism of the present invention.
In the rope winding mechanism in FIG. 8, the surface of the axial tube 101 includes concave, helical slots 104 starting from a positioning hole 109 (shown in FIG. 17) along the winding direction of rope 103. A gap between the slots 104 is typically approximately the diameter of the rope 103 or slightly larger. The slots 104 can be made by such methods as injection molding, machining, or casting. The present invention is not limited to these manufacturing methods.
In the securing mechanism of the invention as shown in FIGS. 11-17, the positioning hole 109 is located on the curvature 200 of the Y-shaped cross section 202 that is on the surface of axial tube 101. The positioning hole 109 located on curvature 200 orients the rope 103 exiting from the positioning hole 109 in an almost-tangent angle to the axial tube 101.
In the rope securing mechanism of the invention as shown in FIG. 17, the installation hole 110 is on the aforementioned axial tube 101. The installation hole 110 is connected to positioning hole 109. The diameter of installation hole 110 is greater than the diameter of the positioning hole 109. A seal head 111 is on one end of the rope 103. The diameter of the seal head 111 is smaller than that of the installation hole 110 and larger than the diameter of the positioning hole 109. Thus the seal head 111 on rope 103 can be inserted into axial tube 101 through installation hole 110, and slid into the positioning hole 109. The diameter of the positioning hole 109 is smaller than that of the seal head 111, and thus the rope 103 stays attached to the axial tube 101.
In the rope securing mechanism in the invention as shown in FIGS. 16 and 17, a stopper plate 112 is located between the installation hole 110 and the positioning hole 109. The stopper plate 112 is part of the axial tube 101. After the seal head 111 end of the rope 103 is inserted into the installation hole 110 and slid into positioning hole 109, the stopper plate 112 is bent to let the rope slide through. The stopper plate 112 is pressed down when the installation is complete to prevent rope 103 from sliding from positioning hole 109 back to installation hole 110. The positioning of the stopper plate 112 is shown in detail in FIGS. 13 and 14. In FIG. 13, the stopper plate 112 is shown in the pressed down state against the rope 103. In FIG. 14, the stopper plate 112 is shown in the bent (open) state enabling the rope 103 to slide past the stopper plate 112.
In the rope positioning mechanism shown in FIGS. 8-12 and 15, the press portion 113 on the rope securing latch 102 has a lateral cross-section having an “N” shape to match the cross-section profile of the rope to improve the attaching force between the rope 103 and the rope securing latch 102.
In the rope positioning mechanism according to principles of the invention as shown in FIGS. 12 and 15, the rope securing latch 102 is securely attached to the rectangular slots 115 on the axial tube 101 through the elasticity of triangular latches 114. Typically, the rope securing latch 102 is made of a metallic material.
It is to be understood that the above-identified embodiments are simply illustrative of the principles of the invention. Various and other modifications and changes may be made by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof.
Patent Application
20080001133
