Abstract:
A come-along for pulling loads includes a rope winding mechanism that enables the rope to be wound and fed out smoothly. The rope winding mechanism includes a positioning hole that reduces the angle between the secured end of the rope and an axial tube about which the rope is wound. The come-along also includes a rope securing mechanism. The secured end of the rope has a seal head that fits through an installation hole and rests against the positioning hole. A helical slot around the axial tube enables the rope to wind evenly.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Applicant claims priority under the Paris Convention for the Protection of Industrial Property to Chinese Patent Application Number 200420021883-6 filed in the People&#39;s Republic of China on Apr. 6, 2004, and to Chinese Patent Application Number 200410067190.5 filed in the People&#39;s Republic of China on Oct. 15, 2004 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; 
         FIG. 17  is a side view of the axial tube including a rope securing mechanism of the present invention; and 
         FIGS. 18A-18H  show an axial tube according to various respective embodiments 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  (as shown in  FIG. 6 ), 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  8 - 8  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. 11  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  112  in a pressed-down state and  FIG. 14  is an illustration of the stopper plate  112  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  (as identified, e.g., in  FIG. 16 ) 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 . 
       FIG. 11  shows a first outwardly facing circumferential surface portion  180 , a second radial surface portion  182  and a third radial surface portion  184 . As illustrated, the second radial surface portion  182  and third radial surface portion  184  each diverges substantially smoothly from a radial orientation to a circumferential orientation. Also shown are further radial surface portions  186  and  188 . Radial surface portions  182 ,  184 ,  186  and  188  include respective surface regions disposed in substantially parallel spaced relation to one another. 
     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 . Before 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 ,  15  and  17 , 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.