The present invention relates to tensioning devices, more particularly for devices used to tension a medium around a tree for safely securing hunting tree stands or climbing ladders.
Tensioning devices for hunting tree stands currently used in the industry are generally hand operated commonly available devices that may not create safe tension in the medium that passes around a tree to secure a hunting tree stand. Tensioning devices commonly known in the art vary in design and the choice of tensioning devices commonly available are susceptible to damage by falling limbs, animals, sun and ultraviolet deterioration. In many cases, the person installing the tensioning device is not able to create enough tension in the device to safely install the tree stand. Some hunters install tree stands using only a chain at a tension that the person installing the stand can impart to the chain by hand. Others use commercially available ratchet straps made of fibers that are susceptible to damage and stretch over time. Furthermore, ratchet straps are difficult to install by hand to safe tension for securing the stand.
Many times, a hunter has multiple tree stands installed in various locations and a compact and easily operated tensioning device would save time installing tree stands and ensure that each is installed safely. Additionally, climbing ladders may be installed and removed each time a hunter goes hunting.
There is therefore a need in the art for a tensioning device for hunting tree stands that is easy to install and generates sufficient tension in the medium surrounding the tree to safely secure the tree stand to the tree.
In one aspect there is disclosed a tensioning device for tree stands and climbing ladders that includes a mechanism to provide tension in a cable utilizing a common drive feature and a threaded element.
More particularly, the threaded elements are disposed within a tube or housing wherein rotation of a threaded tube draws a cable into the tensioning device to create tension in a medium attached to a tree stand surrounding a tree.
The drive insert is attached to the end of a cable and is installed inside of a threaded tube. The drive insert may be located on the cable with clearance to the cable and an additional stop added to the cable to react against the drive insert, if desired. The drive insert may also include an area for crimping on to the cable.
The threaded tube is disposed within an outer tube. The outer tube does not rotate during installation and it provides an attachment point to a bracket that attaches to the tree stand.
The outer tube may have a variety of designs to attach to the tree stand or climbing ladder. In one embodiment, a hook may be attached to or may be part of the outer tube or housing to provide the attachment to the tree stand or bracket.
The outer tube may be painted or otherwise coated for camouflage or decorative purposes or for corrosion resistance. Soft coatings for noise dampening may also be used.
A drive member is installed at one end of the threaded tube to allow the threaded tube to be rotated inside the outer tube to draw the cable in. In one aspect, the drive member may be rigidly attached to the threaded tube to drive it rotationally. In another aspect, the drive member may be installed in a manner that acts as a clutch to prevent overload of the cable and provide feedback to the person installing the tensioning device that it is installed to the proper cable tension.
The clutched drive member design may include one or more clutch pins to match with radiused geometry inside the end of the threaded tube and have a spring to provide force holding the one or more pins into the radiused geometry in the threaded tube. Those skilled in the art recognize that a variety of designs may be used to act as a clutch on the drive mechanism of the tensioning device.
The clutch may be designed in a manner that is asymmetrical to protect against over travel in the cable release direction. In one aspect, the geometry on the inside of the end of the threaded tube may have radiused geometry where one side of the radiused geometry is shallower than the other side, allowing the clutch pins to disengage the radiused geometry at a lower torque in the release direction.
A retaining ring may be used to retain the threaded tube and drive member into the outer tube to ensure the assembly remains together, even when the tensioning device is loosened causing the drive insert to contact the inside of the outer tube or housing at the cable exit end. In the design incorporating a clutch, the retaining ring may provide a stop for the drive member and clutch assembly to ensure that the components of the clutch stay engaged. Those skilled in the art recognize a variety of retainer designs may be used to accomplish this design purpose.
A cable bushing may be installed in the end of the outer tube opposite the drive member. The cable bushing provides support for the cable as it exits the tensioning device, as the exit direction of the cable may vary. For example, when installed on a small diameter tree, the cable may exit the tensioning device at a severe angle. In one aspect, the outer tube may be designed as a single piece and the geometry of the cable exit may be part of this single piece outer housing.
The cable bushing may be pressed or crimped into the outer tube to secure it in place and seal out water. The cable bushing may also be coated with a sealant or adhesive to assist in sealing the cable bushing to the tube. The cable bushing may also include an internal groove for the purpose of installing a seal, such as an o-ring, to seal the cable exit from contaminants.
The cable may include a cable hook to be attached to a chain or other medium to be wrapped around the tree. Those skilled in the art recognize that the cable hook may have many different designs and methods of attachment to the cable.
A thrust washer may be installed inside the outer tube to provide a smooth and flat surface for the threaded tube to rotate against while cable tension is increasing. A bearing with roller elements may also be used.
An anti-rotation member may be installed inside the threaded tube to prevent the drive insert from rotating as the threaded tube is rotated, thus retracting the cable and creating tension for installation of the tree stand or climbing ladders.
A bracket or hook may be attached to the outer tube to attach the tensioning device to the tree stand or climbing ladder. The design of the bracket may be such that it can be easily attached to the stand or ladder with only one hand.
Referring to the Figures, there are shown embodiments of a tensioning device 10 for tree stands or climbing ladders. The tensioning device 10 may include an outer tube 12 and a cable 14. The tensioning device 10 may also include a threaded tube 16 which rotates to retract the cable 14 to a desired tension.
As seen in
The cable 14 may include an attachment structure such as a cable hook 26 to attach the tensioning device 10 to a medium or an item to be tied down. The cable hook 26 may be crimped or cast on to the cable 14. Those skilled in the art recognize a variety of hook designs may be used to accomplish this attachment.
A drive insert 28 may be attached to the end of the cable 14 opposite the cable hook 26. The drive insert 28 may be threaded to match the threads 18 of the threaded tube 16. The drive insert 28 may have one or more holes 29 formed therein allowing passage of an anti-rotation member 30. The drive insert 28 may also include a reduced diameter section 32 to allow for crimping to the cable 14.
Thrust washers 34 may be positioned so that the threaded tube 16 may have a bearing surface to rotate against that is smooth and flat. The thrust washer 34 may include geometry for clearance of the anti-rotation member 30 relative to the thrust washer 34. Those skilled in the art recognize that a ball or roller bearing may be installed in place of the thrust washers 34.
A retaining ring 36 may be installed within the outer tube 12 adjacent the thrust washer 34 to prevent the threaded tube 16 from translating inside the outer tube 12 as cable tension is increased.
As stated above, anti-rotation members 30 may be installed within the outer tube 12 either by press fit or some other method to prevent the drive insert 28 from rotating as the threaded tube 16 is rotated. The anti-rotation members 30 may be positioned inside the threaded tube 16 and include extensions which pass through holes 29 in the drive insert 28. In one aspect, the anti-rotation members 30 may include three members; however, those skilled in the art recognize that a variety of designs would function to prevent rotation of the drive insert 28.
A drive member 24 may be used to rotate the threaded tube 16 using a cordless drill or other hand tools. In one aspect, the drive member 24 may include an external hexagonal structure 38 to rotate the threaded tube 16. Those skilled in the art recognize that a variety of shapes and configurations may be used as a drive feature to rotate the threaded tube 16 for operation of the tensioning device 10.
A drive member 24 may be rotated by hand or power tools. When rotated, the drive member 24 may rotate the threaded tube 16. As the threaded tube 16 is rotated, the threads 18 on the inside of the threaded tube 16 engage the external threads on the drive insert 28. The drive insert 28 is restricted from rotation by the anti-rotation members 30, allowing the drive insert to move upward on the threads 18 of the threaded tube 16 toward the drive member 24 and retracting the cable 14 and creating tension.
In one aspect, the drive member 24 may be directly and rigidly attached to the threaded tube 16 allowing the threaded tube 16 to be rotated to retract the cable 14 and provide tension. In another aspect, the drive member 24 may be integral with the threaded tube 16 as one component.
Alternatively, the drive member 24 may be coupled to the threaded tube 16 in a manner that allows slippage when proper tension is reached thus acting as a clutch. In this embodiment shown in
A clutch spring 44 may be positioned between two clutch pins 42 inside the slot 40 of the drive member 24 to hold the clutch pin 42 into radiused slots 46 formed in the threaded tube 16 until the desired torque is obtained. The movement of the clutch pin 42 into and out of the radiused slots 46 of the threaded tube 16 may provide audible and/or tactile feedback that proper cable tension has been obtained.
The cable 14 force may be directly proportional to the input torque applied to the drive member 24 allowing for control of the cable tension. Various numbers and shapes of the clutch components such as the slots 46 and pins 42 can be controlled based on the design of the clutch and threaded elements. Those skilled in the art will recognize that various designs may be utilized to allow slippage in the mechanism to prevent excessive cable 14 force.
Alternatively, the radiused slots 46 may have an asymmetrical design. In one aspect, the radiused slots 46 may have a geometry wherein the depth of the radiused slot 46 is less on one side than the other. The reduced depth of the radiused slot 46 on one side may allow the clutch pins 42 to overcome the clutch spring 44 and travel out of the radiused slot 46 at a lower torque in one direction. As illustrated, the clutch pins 42 may travel out of the radiused slots 46 in the direction where the tensioning device is extending the cable 14 to prevent the tensioning device 10 from becoming locked if it were over-released.
In one aspect, a locking cap 48 may be placed over the outer tube 12 and the drive member 24. The locking cap 48, when installed, prevents access to the drive member 24 so that the tensioning device 10 may not be loosened without removing the locking cap 48. The locking cap 48 may include a keyed actuator. When the locking cap 48 is installed over the outer tube 12 and drive member 24 it engages a locking groove 50 requiring actuation of a key tumbler to remove the locking cap 48 from the outer tube 12.
In another alternative embodiment shown in
A clutch spring 44 may be positioned about the pin 43 and between two clutch pins 42 inside the slot 40 of the drive member 24 to hold the clutch pins 42 into radiused slots 46 formed in the threaded tube 16 until the desired torque is obtained. The movement of the clutch pin 42 into and out of the radiused slots 46 of the threaded tube 16 may provide audible and/or tactile feedback that proper cable tension has been obtained.
The cable 14 force may be directly proportional to the input torque applied to the drive member 24 allowing for control of the cable tension. Various numbers and shapes of the clutch components such as the slots 46 and pins 42 can be controlled based on the design of the clutch and threaded elements. Those skilled in the art will recognize that various designs may be utilized to allow slippage in the mechanism to prevent excessive cable 14 force.
Alternatively, the radiused slots 46 may have an asymmetrical design. In one aspect, the radiused slots 46 may have a geometry wherein the depth of the radiused slot 46 is less on one side than the other. The reduced depth of the radiused slot 46 on one side may allow the clutch pins 42 to overcome the clutch spring 44 and travel out of the radiused slot 46 at a lower torque in one direction. As illustrated, the clutch pins 42 may travel out of the radiused slots 46 in the direction where the tensioning device is extending the cable 14 to prevent the tensioning device 10 from becoming locked if it were over-released.
Again referring to
The drive insert 28 in the depicted embodiment of
Thrust washers 34 may be positioned so that the threaded tube 16 may have a bearing surface to rotate against that is smooth and flat. Those skilled in the art recognize that a ball or roller bearing may be installed in place of the thrust washers 34.
A spacer 69 may be positioned between the drive insert 28 and clutch pins 42. In this manner an axial load is not applied to the clutch pins 42 and spring 44 when the tensioning device 10 is actuated to release a load from the tensioning device 10.
Referring to
The invention has been described in an illustrative manner. It is to be understood that the terminology, which has been used, is intended to be in the nature of words of description rather than limitation. Many modifications and variations of the invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the invention may be practiced other than as specifically described.
Number | Date | Country | |
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61555612 | Nov 2011 | US |