Patent Grant
8083210
The invention relates to a jack-stand power unit for a two part jacking system, and to a floor jack, for lifting and supporting a corner of an automobile; particularly to a mechanism for controlling the position of the tubular handle. The inventor of the present invention is a pioneer of the two part jacking system and holds numerous patents for two part jacking systems, some of which are described below.
Briefly, the commercial two part jacking system consists of a mobile power unit and a set of separate mechanical jack stands. Examples of the two part jacking system and mobile power unit are described in detail in U.S. Pat. Nos. Re.32,715; 4,589,630 and 6,986,503. Some examples of the jack stands are described in detail in U.S. Pat. Nos. 4,553,727; 5,110,089; 5,183,235 and 5,379,974. The stands are capable of being vertically extended and retracted from the garage floor or road surface and, when extended, can be locked in place at a desired position by a ratchet and pawl assembly. The power unit has a wheeled mobile chassis adapted to carry a plurality of the jack stands, and has a pair of lift arms adapted to mate with the outermost jack stand for placement and removal.
In use, the commercial mobile power unit is operated from its handle. It is maneuvered under a vehicle to place a jack stand in a desired location for lifting and supporting the vehicle. The power unit is activated from the handle, and the jack stand is then extended vertically to the desired height, thus lifting the vehicle on the stand. By operating the controls at the end of the handle, the operator can cause the power unit to disengage from the stand, and the stand will remain locked in its extended supporting position under the vehicle.
After the stand is raised and locked in place supporting the vehicle, or other load, in an elevated position, the power unit lift arms are lowered and the power unit is disengaged from the stand and pulled away, leaving the stand in position supporting the load. Another jack stand, carried within the chassis, is automatically transferred to the forward end the chassis for placement at another desired location of the vehicle or for use in lifting and supporting another vehicle.
To lower the vehicle and remove the stand, the power unit is maneuvered to re-engage with the stand. The engagement causes any existing jack stands carried within the chassis to be automatically transferred rearward within the chassis. By manually operating a control at the end of the handle, the operator can cause the power unit to re-engage with the stand, and to disengage the ratchet locking mechanism of the stand, and to lower the stand to its original position. The power unit remains engaged with the stand and can be pulled away from the vehicle with the stand carried within the chassis.
The original commercial power units were adapted to carry up to four jack stands within the chassis. Additional jack stands could be acquired to reload the power unit, so that a single power unit could be utilized to efficiently place and actuate numerous jack stands. It was found that many commercial users would utilize all of their available jack stands, and the power unit was thereafter useless until another jack stand was available to be extracted and reused. The present inventor developed a two position lift bridge (and also an automatic-slide-forward bridge) that adapted the power unit to function as a load-lifting jack to more fully utilize the power unit. This invention is illustrated in U.S. Pat. No. 6,779,780 entitled Lift Bridge For Use With a Power Unit and a Load Lifting Jack, along with several other patents related to additional features of the lifting system.
In the continuous development and manufacture of these lifting devices, unique improvements often result in additional inventions. As in the present invention, an inexpensive, reliable mechanism was needed to control the position of the tubular handle of the power unit.
In view of the foregoing necessity, it is an object of the present invention to provide an improved mechanism for controlling the position of the handle of the power unit. Since the handle of a power unit functions similarly to the handle of a mobile hydraulic floor jack, the mechanism is applicable to both the power unit and to the mobile hydraulic floor jack.
The foregoing objects are accomplished by the present invention for a mechanism for positioning a tubular handle. A floor jack includes a rectangular frame having a forward end, a rearward end, longitudinal side flanges extending upward and having a pair of external wheels attached on axels to the side flanges near the rearward end of the frame. A hydraulic cylinder is secured at the rearward end, wherein the cylinder includes an actuator piston. A tubular handle has a T-bar hand grip at the proximal end, and a yoke at the distal end thereof with lateral axels pivotally attached to a pair of vertical side brackets at the rearward end of the frame.
One of the vertical side brackets has a series of arcuate upper surfaces concentric with the lateral axel of the yoke, including a large radius forward portion extending from about 180° to about 90°, then a small radius arcuate notch portion extending from a forward edge at about 90° to a rearward edge at about 40°, then an intermediate radius rearward portion extending from about 40° to about 0°.
The yoke has a barrel attached thereto and aligned radially over the circular upper surfaces of the side bracket. The barrel has an upper surface and a plunger therein with an upper end extending above the upper surface of the barrel, and a lower end for extending below the barrel and into the arcuate notch portion of the side bracket. The barrel includes a compression spring for biasing the plunger in the downward direction;
A plunger control level has an extended proximal portion for positioning the lever, and has a rectangular distal end that is pivotally attached to the upper end of the plunger. When the shorter side of the rectangular end is positioned against the upper surface of the barrel, the lower end of the plunger is fully extendable into the arcuate notch portion of the side bracket and retained between the forward edge of the notch portion and the rearward edge of the notch portion for fixing the movement of the handle to maneuver the floor jack. When the longer side of the rectangular end is positioned against the upper surface of the barrel, the lower end of the plunger is partially extendable into the arcuate notch portion and retained at the forward edge of the notch portion and not retained at the rearward edge of the notch portion, for freeing the handle to pump the hydraulic cylinder. When the control lever is pulled upward, the plunger is retracted and not retained by the forward edge of the arcuate notch portion, for folding the handle over the hydraulic jack and power unit.
While the novel features of the invention are set forth in the appended claims, the invention will be better understood along with other features thereof from the following detailed description taken in conjunction with the drawings, in which:
The figures and the following specification may describe and define several distinctive inventions that are interrelated within a lifting and supporting system, and may be included in patents (or pending applications) having distinctive sets of claims directed to the respective invention. The improved power unit and jack stands are discussed and described in terms of an automotive jack system, but it should be understood that the system is not limited to automotive uses and can be utilized for lifting and supporting any type of load. Also, some of the inventions are described in terms of the power unit, and as in the present invention are also applicable to a mobile hydraulic floor jack.
Referring first to
The power unit 10 has a generally rectangular frame 20 having a central longitudinal axis, a forward end 21 for loading and unloading the jack stands, a middle portion 22 for securing the lifting mechanism, a rearward end 23 for controlling the power unit, and a bottom 24 thereof The bottom 24 has a pair of horizontal rounded-nose extensions 25 (also forming a rectangular slotted opening) for engaging the jack stands.
The bottom 24 of the frame further has the forward end 21 thereof substantially flat for providing a solid lifting platform, and has the middle portion and rearward end thereof angled longitudinally upwardly for facilitating mobility of the power unit by a pair of wheels 28 located near the rearward end 23 of the frame.
A hydraulic cylinder 29 having an extendable ram 30 at the forward end thereof, and having a rotatable control valve 31 at the rearward end thereof, is attached along the longitudinal center near the rearward end 23 of the bottom 24 of the frame. The hydraulic cylinder preferably utilizes dual piston type actuators 32 having a first piston actuator for rapidly extending the ram with only a few strokes, until a load exceeding about 150 pounds is encountered; the second piston actuator then takes over to extend the ram (i.e. to lift the load) in the conventional manner.
The frame has a pair of longitudinal side flanges 33 extending upward from the bottom 24 thereof; and has the pair of wheels 28 attached to the outer sides of the flanges on lateral axels near the rearward end 23 thereof. Each side flange has an upper edge 34 with a rounded vertical nose 35 at the forward end 21 thereof and a smooth blunted vertical tail 36 at the rearward end thereof, and has a smooth arcuate contour extending upwardly from the rounded nose to about the height of the wheels and then downwardly mating with the blunted tail, providing an attractive appearance for the frame of the power unit. Each flange further includes a U-shaped longitudinal retaining channel 37 facing inwardly and attached horizontally along the inner sides of the middle portion thereof. The rearward end 23 of the frame includes a generally rectangular cover plate 38 that extends over and along the upper edges 34 of the side flanges 33 and covers the hydraulic cylinder 29 and some of the control mechanism. The cover plate is contoured to match the upper edge of the side flanges, and provides some protection for some of the components and a clean appearance for the rear of the power unit 10.
The power unit includes the pair of lift arms 39 that act in parallel and have forward ends 40, middle portions 41 and rearward ends 42. The lift arms are interconnected at the rearward ends thereof by a lateral push bar 43, with the respective ends of the push bar slidably retained (in suitable pivotal bushings) within the respective retaining channel 37 of the flanges; and the forward ends of the lift arms extend toward the forward end 21 of the frame.
A pair of connecting arms 44 act in parallel and have forward ends 45 and rearward ends 46, have the respective forward end pivotally connected (at 45) near the forward end of the respective flange of the frame 20. The respective rearward end is pivotally connected (at 46) on the middle portion 41 of the respective lift arm 39.
The hydraulic cylinder 29 has the ram 30 at the forward end thereof attached to the center of the lateral push bar 43. When the ram is extended, the push bar and the rearward ends 42 of the lift arms 39 are translated forward along the retaining channels 37 in the flanges of the frame, and the forward ends 40 of the lift arms are thereby raised (in scissor-like fashion with connecting arms 44).
The forward ends 40 of the lift arm 39 have also a pair of leveling pads 47 acting in parallel and are pivotally attached to the outer sides thereof (through suitable bushings and fasteners co-axel with the discs 70), for providing a level platform thereon for supporting the lift bridge 14. Each leveling pad includes a vertical rectangular plate having a first lever arm 48 extending downward and forwardly at an angle from the plate, and with the plate having an upper flange 49 extending horizontally therefrom, providing a level platform thereon. The platform has another flange extending vertically downward and forwardly therefrom forming a second parallel lever arm 50 thereon. The first and second lever arms having mating lateral apertures 51 in the forward ends thereof.
The leveling pads 47 utilize a pair of leveling links 52 that have a forward end 53 connected to the apertures 51 at the forward ends of the lever arm of the leveling pad, and have a rearward end 54 connected to a point (at 54) on the connecting arm 44; so that as the forward ends of lift arms 39 are raised and lowered, the platforms formed by the upper flanges 49 of the leveling pads are maintained in a substantially horizontal orientation. The leveling pads, with the double lever arms and leveling links, provide a strong, rugged level platform for use with the lift bridge 14.
One of the horizontal flanges 49 (the left one in the present example) has a vertical aperture 56 therein for retaining one side of the lift bridge. This flange further has a threaded vertical aperture 58 therein for securing one side of the lift bridge. The threaded aperture can be form into the flange with a conventional die, or can be provided by securing a suitable nut on the underside of the flange.
A tubular operating handle 60 typically extends rearward and upwardly from the rearward end 23 of the frame of the power unit 10. The tubular handle has a yoke 106 at the distal end thereof having a pair of lateral axels 108 pivotally attached within a left side bracket 110 and a right side bracket 112 with suitable bushings and fasteners. The position and operating range of the handle is manually controlled by a mechanism 114 located on the right side of the yoke.
The tubular handle 60 has a T-bar hand grip 61 transversely attached to the proximal end thereof; and further has a control knob 150 secured to a control shaft 151. The control knob is fixedly attached to the rotatable control shaft 151 that extends through the tubular handle with the distal end thereof connected to a universal joint 152 so that the center of the u-joint is precisely between the lateral axels 108; and the other end of the u-joint is interconnected through a suitable coupling shaft 153 to the rotatable control valve 31 on the hydraulic cylinder. The handle also includes a control lever 154 for controlling the inter-engagement and the cooperative action of the power unit and the jack stand 12.
The operating handle is used in a conventional manner for maneuvering the power unit about on its wheels, operating the hydraulic control valve, and pumping the handle up and down for providing energy to actuate the hydraulic cylinder.
Handle Control Mechanism
To maneuver the power unit into a desired position, the tubular handle 60 is preferably fixed at about 45° so that the proximal end of the handle can be pressed downward to slightly raise the forward end of the power unit for maneuvering it on its rear wheels 28. To pump the hydraulic cylinder 29, the tubular handle is preferably arranged to be freely rotatable through an angular range of about 60° to 0°. It is preferable to restrict the tubular handle from falling forward past 90° during the pumping operation (to avoid any contact with the automobile), and also preferable for the tubular handle to be folded over the power unit to about 180° for compact shipping and storage.
Referring also to
The tubular handle 60 includes the yoke 106 having the lateral axels 108 pivotally attached to the respective side bracket 110 and 112 at the rearward end of the frame of the power unit. The yoke has a pair of flanges 116 extending rearward and supporting a lateral cylindrical cam 118 for engaging each actuator piston 32 of the hydraulic cylinder 29 on successive down strokes of the tubular handle.
The mechanism for controlling and positioning the tubular handle 60 includes the right vertical side bracket 112 having a series of arcuate upper surfaces concentric with the lateral axel 108 of the yoke (see
The yoke 106 (see
The mechanism is controlled by a plunger control lever 136 having an extended proximal handle portion 137 for manually positioning the lever, and having a rectangular distal end 138 that is pivotally attached (at 138) to the upper end 131 of the plunger extending above the barrel. The barrel includes a means for biasing the plunger in the downward direction, shown as an internal compression spring 134 (and can also be provided by a suitable external spring or an internal or external cylindrical elastomeric compound). The biasing means urges the rectangular distal end (either one side or the other side) against the upper surface 129 of the barrel in a “snap-over” manner, depending on the position of the control lever.
Referring particularly to
The position of the barrel 128, the length of the plunger 130 (i.e. about 1.80 inches or 45 mm) and the dimensions of the respective sides 139, 140 of the rectangular distal end 138, are arranged to function with the upper surfaces of the bracket. When the control lever 136 is down (see
Referring particularly to
The configuration of the series of arcuate upper surfaces preferably includes the forward portion 120 extending from about 180° to about 90°, the small radius arcuate notch portion 122 extending from a forward edge at about 90° to a rearward edge at about 40°, then the intermediate radius rearward portion 124 extending from about 40° to about 0°. However, a variety of arcuate surfaces may be provided including an arrangement wherein the forward portion extends from about 180° to about 50°, the small radius arcuate notch portion extends from a forward edge at about 50° to a rearward edge at about 40°, then the intermediate radius rearward portion extends from about 40° to about 0°; this arrangement basically provides a fixed notch for the plunger, and further allows for pumping from about 45° down to 0° for operating the power unit.
Referring particularly to
It is concluded that the present invention provides an improved mechanism for controlling the position of the handle of the power unit, and a floor jack.
While specific embodiments and examples of the present invention have been illustrated and described herein, it is realized that modifications and changes will occur to those skilled in the art. It is therefore to be understood that the appended claims are intended to cover all such modifications and changes as may fall within the spirit and scope of the invention.
| Number | Name | Date | Kind |
|---|---|---|---|
| 2218163 | Carlson | Oct 1940 | A |
| Number | Date | Country | |
|---|---|---|---|
| 20080303009 A1 | Dec 2008 | US |
