The present disclosure generally relates to a jack stand, such as a jack stand having a modulating mechanism (e.g., a modulator). For instance, in certain embodiments, the jack stand includes a ratcheting mechanism and may, therefore, be termed a ratcheting jack stand. For example, the present disclosure relates to a jack stand that integrates an engagement element, such as an engageable pawl and/or a release button for sequentially engaging a plurality of engagement element receivers, e.g., pawl receiver, for easily manipulating the vertical height of an elongated support, such as a central shaft, in the jack stand.
Jack stands have been utilized for many years to support or raise large loads. For instance, jack stands may be used to lift equipment for ramps, raise an automobile to be repaired, or to raise and stabilize other devices to gain access to difficult to reach places under the device. The jack stand must be able to safely support and lift heavy loads and other heavy equipment. Conventional jack stands have been used for this purpose. For example, jack stands are commonly placed under the frame or axle of a vehicle to be raised.
For this purpose, jack stands typically include a support, such as a central shaft, that is extendable from within the jack stand and is capable of being raised to a designated height and locked in place. The jack stand maintains the vehicle in this raised position until work is completed. Easy adjustability and positive locking of the jack stand at desired heights are important features of a jack stand. Moreover, the strength and stability of the jack stand are also features important to ensuring maximum safety while maintaining such heavy loads in elevated positions.
Conventional jack stands have a strong stable base typically formed from a strong material such as steel. A support or shaft central to the base extends out and above the base. The central shaft may also include a platform for stabilizing the lifted load. Accordingly, the lifted load rests against the platform when the central shaft is extended out from the base. The height of the central shaft, extending beyond the top of the base, along with the height of the base itself, determines the height at which the load is to be maintained.
In general, there are two mechanisms for maintaining the lifted load on the platform and at a desired height. In one mechanism, the jack stand receives a pin inserted through a plurality of holes drilled through the base and the central shaft. The holes in the central shaft are placed intermittently along the length of the shaft thereof. The jack stand mechanically raises the central shaft whereupon reaching the approximate desired height, a pin is inserted through a hole in one side of the base, through a corresponding hole in the central shaft and out another hole on an opposite side of the base.
The inserted pin maintains the central shaft at the desired elevated height above the base. The pin should be inserted through both sides of the base to prevent inadvertent withdrawal of the pin therefrom. One danger from an inadequately inserted pin is that the jack stand slips. Thus, an improperly inserted pin may not adequately hold the central shaft in place. Further, one cumbersome aspect of this pin design is that it is necessary to remove and reinsert the pin in the jack stand when altering the height of the central shaft.
Additionally, while the pin is a generally acceptable way to maintain the jack stand in an elevated position, it does have several drawbacks. For instance, some jack stands incorporate a locking element that prevents the pin from withdrawing from the holes in the base and the corresponding hole in the central shaft. The locking element slides through a hole formed through the width of the pin. The locking element is greater than the width of the holes the pin is inserted into to prevent the pin from sliding out of the holes. Commonly, users may intentionally fail to insert the locking element for the sake of convenience and speed. Moreover, the pin or the locking element may be easily misplaced when removed form the jack stand. The jack stand is thereafter completely inoperable until at least the pin is found. Aligning the pin with the holes in the base and central shaft of the jack stand can also be difficult. The weight of the central shaft can cause the pin to slip out of alignment before the pin is inserted through the central shaft and out other side of the jack stand base. Any slippage of the central shaft can cause injury to the person operating the jack stand.
Another jack stand design includes a central shaft having a plurality of teeth formed on one edge that engage a pawl attached to an external handle. This mechanism does not require any removable parts to engage or disengage the pawl to the teeth on the central shaft or to hold the platform at a desired height. But, in some designs, the handle that operates the pawl can be easily moved such that the pawl may accidentally disengage from the teeth on the central shaft. For example, the weight of the corresponding handle biases the pawl against the teeth of the central shaft. Simply applying enough force to rotate the handle against its own weight, typically a relatively moderate force, can disengage the pawl from the teeth in the central shaft. It is highly possible, therefore, to inadvertently jostle the handle while the jack stand is under load. The central shaft, and corresponding platform holding the load, may quickly fall when the pawl disengages the central shaft. Disengagement of the pawl from the central shaft, when under heavy loads, can certainly damage the jack stand, the load being maintained thereby, as well as the jack stand operator and nearby equipment. Further, such jack stand designs do not typically provide a means for easily disengaging the pawl from the central shaft.
Thus, there is a need in the art for a jack stand that is automatically engageable with a central shaft and/or a jack stand that can be easily disengaged therefrom to manipulate the height of the central shaft. Such a jack stand may include a ratcheting mechanism having an engagement element, such as a pawl that is capable of automatically engaging an engagement element receiver, e.g., a pawl receiver, and/or remaining engaged therewith for maintaining the height of the central shaft of the jack stand. In certain embodiments, the jack stand may include an exterior release button that easily disengages the engagement element, e.g., pawl, from a complementary receiver positioned on the central shaft. The present invention fulfills these needs and provides further related advantages.
The present disclosure for a jack stand generally includes a housing which housing may form a base for the jack stand. Also included may be a support, such as a central shaft. The housing may be adapted for receiving the central shaft there through. The central shaft may be configured for being moved within the housing. For instance, in certain embodiments, the central shaft is extendable or retractable with respect to the housing. For example, in certain embodiments, the jack stand includes a modulating mechanism or modulator, such as a ratcheting mechanism, for automatically moving the central shaft with respect to the housing. Specifically, in certain embodiments, a ratcheting mechanism is disposed within a collar of the jack stand and employed so as to raise the central shaft with respect to the housing, e.g., base.
In certain instances, the ratcheting mechanism includes a lever, which lever may be rigidly attached to a lifting arm. The lifting arm may include a spring-loaded engagement element, such as a finger, that engages any one of a plurality of engagement element receivers, or slots, formed in a side of the central shaft. Accordingly, rotation of a corresponding lever may cause the engagement of the engagement element, e.g., spring-loaded finger, with the engagement element receiver, e.g., slot, such that the central shaft is lifted upwardly with respect to the base. The ratcheting mechanism may further include an additional engagement element, such as a pawl, which engagement element is rotationally mounted to an axis member, such as a horizontal axis member, that interconnects the lever to the lifting arm. The pawl is free to rotate relative to the lever and lifting arm.
In certain embodiments, the lifting of the central shaft may be accomplished by rotating the lever arm, e.g., clockwise, to engage the spring-loaded finger with a slot in the central shaft. Continual rotation of the lever arm while the finger is engaged in the slot causes the pawl to start disengaging its respective slot. A spring element may be included, for instance, to continually bias the pawl toward the central shaft while the central shaft is being raised by the lifting arm. The pawl may then reengage another slot, lower than the original slot, once the central shaft travels a vertical distance greater than the distance between individual slots. Accordingly, the pawl is immediately reengaged with the new slot. As set forth above, re-engagement may be further enhanced from the force of a corresponding spring.
In certain embodiments, a release is included. A release may be rigidly coupled to an engagement element, such as a pawl. In such instances, disengagement of the central shaft from the ratcheting mechanism may be effectuated by the depression of the release, which release may be in the form of a button rigidly attached to the pawl. Depression of the release button may cause clockwise rotation of both the release button and the pawl. Such movement may be resisted by a spring element, which spring element may mounted to the housing, such as in a collar of the jack stand housing. Once the pawl is completely disengaged from the slot, the central shaft may be free to move within a channel formed in the housing, such as collar having an opening configured for receiving the moveable shaft there through. Removing the force from the release button may cause the spring in the housing to expand thereby forcing the pawl back into engagement with a slot in the central shaft. The central shaft of the jack stand may there again be locked in place.
Other features and advantages of the present invention will become apparent from the following more detailed description, when taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.
The accompanying drawings illustrate the invention. In such drawings:
As shown in the drawings for purposes of the illustration, the present invention for a jack stand is generally referred to by the reference number 10. As shown in
The central shaft 14 resides within an opening or channel 24 formed in the collar 18 of the housing of the jack stand 10. In certain embodiments, the central shaft 14 remains within the channel 24 when being moved, e.g., extended, relative to the housing, via the lever 20 and the corresponding ratcheting mechanism 19, and while being retracted, after activation of the release button 22. The central shaft 14 may have one or more, e.g., a plurality, of engagement element receivers, wherein the engagement element receiver(s) may be formed as slots 26 positioned, e.g., sequentially, within the shaft and configured for interoperating with the ratcheting mechanism 19. Moreover, the central shaft 14 may have a cradle 28 shown best in
The modulator or ratcheting mechanism 19 is shown in detail in
The ratcheting mechanism 19 may further include a lifting arm 44. The lifting arm 44 may house an engagement element, such as a finger member 46. The finger member 46 may be biased outwardly by a spring element 48. The finger 46 may be a generally flat piece of reinforced steel with a width comparable to the width of the central shaft 14 so as to ensure full engagement with the slots 26. The finger 46 may be configured so as to be strong enough to lift a heavy object such as an axle of a car. The lifting arm 44 may be rigidly attached to the axis 38 and the corresponding lever 20. Accordingly rotation of the lever 20 causes rotation of the axis 38, the lifting arm 44 and the corresponding finger 46. The combination of the finger 46 and the spring 48 facilitate lifting of the central shaft 14 via engagement with a slot 26 from movement of the lever 20.
Although an embodiment of the disclosure has been described in detail for purposes of illustration, various modifications may be made without departing from the scope and spirit of the devices disclosed herein.
The present application claims priority under 35 U.S.C. §119 to U.S. Provisional Application Ser. No. 61/027,587, filed Feb. 11, 2008, entitled RATCHETING JACK STAND, the disclosure of which is incorporated herein by reference.
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Entry |
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Number | Date | Country | |
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20090200528 A1 | Aug 2009 | US |
Number | Date | Country | |
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61027587 | Feb 2008 | US |