Land vehicles – Wheeled – Body with bracketed-type or nonsuspended axles
Reexamination Certificate
2000-02-03
2001-11-06
Swann, J. J. (Department: 3611)
Land vehicles
Wheeled
Body with bracketed-type or nonsuspended axles
C280S043130, C280S043170, C414S458000, C414S495000
Reexamination Certificate
active
06311992
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a lifting device for moving heavy objects. More particularly, this invention relates to a lift dolly possessing a latch mechanism for securely locking the dolly in a lifted position.
2. Description of the Related Art
Often it is desirable to move heavy equipment in a timely fashion. Many devices are available for moving equipment on the factory floor or in a workshop. Some devices such as cranes are capable of transporting and lifting extremely heavy equipment. However, cranes are generally expensive and complex.
Alternatively, simple dollies that pivot about an axle are extremely portable and easy to use. However, these simple dollies are not capable of moving heavy equipment.
Therefore, it is desirable to provide a machine that is capable of lifting and moving heavy equipment in a simple method and timely fashion.
One attempt at providing such a lift dolly is disclosed in U.S. Pat. No. 5,876,173 to English, incorporated by reference in its entirety herein. While the invention described in U.S. Pat. No. 5,876,173 is capable of lifting and transporting machine tools, it has been discovered that the latching mechanism is difficult for a user to properly align, thus leading to an insecure lift.
Another attempt at providing such a lift dolly is disclosed in U.S. Pat. No. 5,957,649 to English, Stahl, and Hees, incorporated by reference in its entirety herein. While the invention described in U.S. Pat. No. 5,957,649 is also capable of lifting and transporting machine tools, it has also discovered that the toggle-type spring latching mechanism may prove to be unreliable to consistently latch and unlatch the dolly frames.
Therefore, it is also desirable to allow a user to align the latching mechanism in a robust, reliable manner. It is also desirable to provide a simple, robust, reliable latching mechanism which can be easily disengaged by a user to set the load down on the floor, without the use of power or hand tools.
For the foregoing reasons, there is a need for a lift dolly that is capable of lifting relatively heavy loads and transporting these loads in a secure fashion. The claimed invention is directed overcoming, or at least minimizing, disadvantages of the prior art.
SUMMARY OF THE INVENTION
The invention relates to an apparatus for lifting and transporting an object. In some embodiments, the lift dolly employs a pedal latch mechanism that attaches to a U-bolt to securely lock the lift dolly in the position of lifting a heavy object. Use of this pedal latch securely provides a secure attachment of the frames of the lift dolly, thus ensuring that the heavy object will not be dropped. Further, once the object has been moved to a desired new location, a user may depress the pedal on the latching mechanism to easily lower the object. Because the pedal latch may be disengaged by the user's foot pushing on the pedal, the user may easily and quickly disengage the lifting mechanism.
Further, because a bracket on the latch has a V-shape in some embodiments, problems associated with misalignment of the two frames is minimized. Also, to compensate for this possible misalignment, parts of the latching mechanism are adjustably attached to the frame.
In some aspects, a lift dolly for lifting and moving an object is described comprising a triangular first frame having a base and an apex, said base of the triangular first frame being connectable to the object, a first pair of castor stems, each castor stem having a castor thereon extending downwardly from the triangular first frame, a second frame having a first tube support, a second tube support, and a pivot end, said pivot end of the second frame being connectable to the object, a second pair of castor stems, each castor stem having a castor thereon extending downwardly from the second frame, and a latching mechanism for releasably securing the triangular first frame to the second frame, having a footplate attached to said first frame, a bracket mounted to the footplate, said bracket extending downwardly from said footplate, a cam latch rotatably mounted to said bracket, and a U-bolt attached to the second frame, said bracket having a notch facing downward for receiving said U-bolt, said cam latch releasably attachable to said U-bolt to secure the first frame to the second frame, said triangular first frame being connected to said second frame such that when a downward force is exerted on the apex of the triangular first frame, the triangular first frame pivots about the castors attached to the first pair of castor stems, thus moving the base of the triangular first frame in an upward direction, said downward force on the triangular first frame causing the triangular first frame to exert a downward force on the first tube support of the second frame, thus causing the second frame to pivot about the castors attached to the second pair of castor stems, thus moving the pivot end of the second frame in an upward direction, the upward movement of the base of the triangular first frame and of the pivot end thereby lever-lifting the object. In some embodiments, the latching mechanism has a torsion spring having a first end and a second end, said first end of said torsion spring functionally associated with said cam latch, said second end of said torsion spring attached to the footplate, said torsion spring locking said cam latch around said U-bolt to secure the first frame to the second frame.
In some embodiments, the notch in said bracket is V-shaped to facilitate the receiving of said U-bolt, and can be integrally formed with said footplate. In others, the U-bolt is adjustably attached to the second frame. Still in others, the lift dolly includes a cam latch, said foot pedal being functionally associated with said cam latch such that by depressing said foot pedal, said cam latch rotates to release said U-bolt thereby disconnecting the triangular first frame from the second frame. In some embodiments, the cam latch is integrally formed. In other aspects, a foot pedal is integrally connected to the cam latch.
Also described is a cam latch having a cam attachment means functionally associated with said bracket to rotatably attach the cam latch the V-shaped bracket, a cam engagement surface, for contacting said U-bolt thereby forcing said cam latch to rotate, a cam notch, for securing said U-bolt into position, a cam foot pedal support, said cam foot pedal support being connected to said foot pedal, said cam notch being located between said cam foot pedal support and said cam engagement surface.
In other aspects, a lift dolly for lifting and moving an object is described comprising a first frame having a base and a top, said base of the first frame being connectable to the object, a first pair of castor stems, each castor stem having a castor thereon extending downwardly from the first frame, a second frame having a first tube support, a second tube support, and a pivot end, said pivot end of second frame being connectable to the object, a second pair of castor stems, each castor stem having a castor thereon extending downwardly from the second frame, a latching mechanism for releasably securing the first frame to the second frame having a footplate attached to said first frame, a bracket mounted to the footplate, said bracket extending downwardly from said footplate, a cam latch rotatably mounted to said bracket, a torsion spring having a first end and a second end, said first end of said torsion spring functionally associated with said cam latch, said second end of said torsion spring attached to the footplate, and a U-bolt attached to the second frame, said bracket having a notch facing downward for receiving said U-bolt, said torsion spring locking said cam latch around said U-bolt to secure the first frame to the second frame, said first frame being connected to said second frame such that when a downward force is exerted on the top of the first frame, the first frame pivots about the castors attached to the first pair of castor stems, thus moving the base
Emerson Electric Co.
Howrey Simon Arnold & White , LLP
Shriver J. Allen
Swann J. J.
LandOfFree
Lift dolly with pedal latch mechanism does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Lift dolly with pedal latch mechanism, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Lift dolly with pedal latch mechanism will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2597392