Patent Application
20170313560
Vehicle lift systems may be used to lift various kinds of vehicles relative to the ground. Some vehicle lifts operate by positioning two runways at, or near, a shop floor level. The vehicle may be then driven or rolled onto the runways, allowing the runways to support the vehicle. The underside of each runway may be attached to a plurality of hydraulically driven lifting assemblies. The lifting assemblies may be actuated to raise the runways and the vehicle to a desired height. Afterward, the vehicle may then be lowered once the user has completed his or her task requiring the vehicle lift. In some cases, the lifting assemblies may comprise a single elongated member which may rotate relative to the floor to pivot the runways upwardly. In other cases, the lifting assemblies may comprise a plurality of linkages which pivot relative to one another to cause the runways to rise upwardly, similar to a pair of scissors.
Other vehicle lift systems are formed by a set of mobile, above-ground lift columns. An example of a mobile column lift system is the MACH 4 Mobile Column Lift System by Rotary Lift of Madison, Ind. Each mobile column may include a hydraulically driven lifting assembly. The mobile columns may be readily positioned in relation to the vehicle. The mobile columns may then be activated such that lifting assemblies actuate to raise the vehicle from the ground in a coordinated/synchronized fashion. The mobile columns may be controlled through wireless communication with a wireless control center. The wireless control center may associate with each mobile column in order to form a synchronized lift.
While a variety of systems and configurations have been made and used to control lift systems, it is believed that no one prior to the inventors has made or used the invention described herein.
While the specification concludes with claims which particularly point out and distinctly claim the invention, it is believed the present invention will be better understood from the following description of certain examples taken in conjunction with the accompanying drawings, in which like reference numerals identify the same elements and in which:
The following description of certain examples should not be used to limit the scope of the present invention. Other examples, features, aspects, embodiments, and advantages of the invention will become apparent to those skilled in the art from the following description, which is by way of illustration, one of the best modes contemplated for carrying out the invention. As will be realized, the invention is capable of other different and obvious aspects, all without departing from the invention. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not restrictive.
A. Exemplary Hydraulic Actuator Assembly
Cylinder assembly (110) includes a hydraulic cylinder (102) and an attachment feature (112). While in the current example, hydraulic cylinder (102) and attachment feature (112) are unitarily connected, it should be understood that hydraulic cylinder (102) and attachment feature (112) may be fixedly coupled with any other suitable means known to a person having ordinary skill in the art in view of the teachings herein. For example, hydraulic cylinder (102) and attachment feature (112) may be fixedly coupled with a plurality of nuts and bolts.
Attachment feature (112) is located at the bottom of hydraulic cylinder (102) in order to couple cylinder assembly (110) to a portion of a vehicle lift assembly, as will be described in greater detail below. In the current example, attachment feature (112) is configured to receive a pin (298) (see
However, it should be understood that rotational capabilities of attachment feature (112) are merely optional. Some vehicle lift assemblies do not require rotation of hydraulic cylinder (102) in order to raise or lower a vehicle. For example, hydraulic cylinder (102) may alternatively be slidably coupled to a portion of vehicle lift assembly. Hydraulic cylinder (102) may alternatively be fixedly coupled to a portion of a vehicle lift assembly (e.g., a lift assembly (250) as shown in
Turning to
Hydraulic cylinder (102) also has a fluid channel (104) associated with the base end (116) and a fluid channel (105) associated with the head end (118). Each fluid channel (104, 105) is in fluid communication with a chamber (106A, 106B) of cavity (106), respectively. Chamber (106A) is defined by interior base end (116), interior annular wall (114), and a radial face (136) of plunger (124). Chamber (106B) is defined by interior head end (118), interior annular wall (114), and a radial face (134) of plunger (124). It should be understood that because plunger (124) is slidable within cavity (106), chambers (106A, 106B) are capable of changing volume as plunger (124) actuates within cavity (106).
Each fluid channel (105, 107) may fill respective chamber (106A, 106B) with hydraulic fluid. Tunnel (104) and rod (122) may fluidly isolate chamber (106B) from the exterior of hydraulic cylinder (102) by using a seal gland or in any other suitable manner known to the art in view of the teachings herein. As will be described in greater detail below, fluid channels (105, 107) may help actuate plunger (124) within cavity (106).
Base end (116) further defines a rotary sensor mount (108) dimensioned to house a rotary sensor (140). Rotary sensor mount (108) is capable of fixing a portion of rotary sensor to hydraulic cylinder (102). While in the current example, rotary sensor mount (108) is a recess defined by base end (116), bolts, nuts, threaded rods, or any other suitable structures may be utilized to fix a portion of rotary sensor (114) to hydraulic cylinder (102).
Linear actuating assembly (120) includes rod (122) having one end fixed to plunger (124) and another end fixed to an attachment feature (126). Rod (122) defines channel (128). Channel (128) extends from the portion of rod (122) that is fixed to plunger (124) toward the portion of rod (122) fixed to attachment feature (126). Rod (122) also has a pin (125) located at the portion of rod (122) fixed to plunger (124). As will be described in more detail below, channel (128) and pin (125) are dimensioned to interact with linear displacement measuring assembly (130) to measure the distance linear actuating assembly (120) actuates relative to cylinder assembly (110). This information may be utilized to determine the individual height of each hydraulic actuator assembly (100) in a vehicle lift system. A vehicle lift system may utilize this data in order to level a vehicle lift system, to limit or manage movement of linear actuating assembly (120), and for other purposes as will occur to those skilled in the art.
While in the current example, rod (122) and attachment feature (126) are unitarily connected, it should be understood that rod (122) and attachment feature (126) may be fixedly coupled with any other suitable means known to a person having ordinary skill in the art in view of the teachings herein. For example, rod (122) and attachment feature (126) may be fixedly coupled with a plurality of nuts and bolts.
Attachment feature (126) is located at the top of rod (122) in order to couple rod (122) to a portion of a vehicle lift assembly, as will be described in greater detail below. In the current example, attachment feature (126) is configured to receive a pin (300) in order to attach rod (122) to a portion of a vehicle lift assembly. Therefore, attachment feature (126) may allow hydraulic actuator assembly (100) to rotate about an axis defined by pin (300). In other words, rod (122) may be rotatably coupled to a portion of vehicle lift assembly via attachment feature (126).
However, it should be understood that rotational capabilities of attachment feature (126) are merely optional. Some vehicle lift assemblies do not require rotation of rod (122) in order to raise or lower a vehicle. For example, rod (122) may be fixedly coupled to a portion of a vehicle lift assembly, or any other suitable attachment feature known by a person having ordinary skill in the art in view of the teachings herein may be employed.
As mentioned above, rod (122) is slidably housed within tunnel (104) of hydraulic cylinder (102). Plunger (124) may be fixed to rod (122) by threads, bolts, or nuts, or any other structures known to one having ordinary skill in the art in view of the teachings herein. As mentioned above, plunger (124) is slidably housed within cavity (106). Plunger (124) is also positioned and dimensioned such that a circumferential face (132) of plunger (124) makes contact with interior annular wall (114). Circumferential face (132) of plunger (124) may be machined with grooves configured to fit elastomeric or metal seals and bearing elements. Plunger (124) is configured to separate cavity (106) into two fluidly isolated chambers (106A, 106B). Therefore, first chamber (106A) and second chamber (106B) defined by cavity (106) and plunger (124) may fill or empty with fluid via fluid channels (105, 107) in order to actuate plunger (124).
As mentioned above, hydraulic cylinder (102) has two fluid channels (105, 107) on opposite ends of hydraulic cylinder (102). Additionally, as mentioned above, first fluid chamber (106A) and second fluid chamber (106B) are in fluid isolation from one another. First fluid channel (107) may be in fluid communication with first chamber (106A) while second fluid channel (105) may be in fluid communication with second chamber (106B). One fluid channel (105, 107) may be in communication with a fluid source such as a pump while the other fluid channel (105, 107) may be in fluid communication with another fluid source such as a reservoir. Fluid sources in fluid communication with channels (105, 107) may fill first chamber (106A) with hydraulic fluid while emptying second chamber (106B) with hydraulic fluid. Because first chamber (106A) and second chamber (106B) are in fluid isolation, plunger (124) and the rest of linear actuating assembly (120) may actuate, similar to that shown in
It should be understood that there may be additional, external forces acting on hydraulic actuator assembly (100) which the pressure in first fluid chamber (106A) or second fluid chamber (106B) may need to overcome in order to actuate linear actuating assembly (120). For instance, if attachment feature (126) is connected to a portion of a vehicle lift assembly that is supporting a portion of a vehicle, the force provided by the pressure in first fluid chamber (106A) acting on radial face (136) may need to overcome the load provided from supporting a portion of the vehicle.
For example, as shown in
Linear displacement measuring assembly (130) includes a rotation sensor (140) and a rotational actuating assembly (150). Rotation sensor (140) includes a rotating element (142) rotatably housed within a static element (148). Static element (148) is fixedly housed within rotary sensor mount (108) of hydraulic cylinder (102). Static element (148) may not rotate or actuate relative to hydraulic cylinder (102). Rotating element (142) defines an aperture (144) and a keyed hole (146). Static element (148) is configured to measure the rotational displacement of rotating element (142). As will be described in greater detail below, rotation sensor (140) is in electrical communication with a circuit board of a vehicle lift assembly or related sensing and/or control circuitry. The vehicle lift assembly may utilize the rotational displacement of rotating element (142) relative to static element (148) in order to monitor the positions of each of any number of hydraulic actuator assemblies (100) utilized in the vehicle lift assembly, using the rotational displacement to calculate the linear displacement of each hydraulic actuator assembly (100), and using that calculated linear displacement in a feedback control loop to manage the operation of the collection of hydraulic actuator assemblies (100).
Rotational actuating assembly (150) includes a rotating shaft (152) and a keyed member (156). Rotating shaft (152) extends from a free end (154) to a coupling end (158). Coupling end (158) is housed within aperture (144) of rotation sensor (140), while keyed member (156) is housed with keyed hole (146). Coupling end (158) may be dimensioned for an interference fit with aperture (144) such that rotating shaft (152) may not actuate in the vertical direction relative to rotating element (142). For example, free end (154) may be dimensioned small enough to fit within aperture (144) while coupling end (158) may be dimensioned for an interference fit. Rotating shaft (152) may be inserted through aperture (144) via free end (154) until coupling end (158) develops an interference fit with aperture (144). Of course, rotating shaft (152) may be fixed in a vertical direction relative to rotating element (142) in any other suitable manner as would be apparent to one having ordinary skill in the art in view of the teachings herein. For example, coupling end (158) may be fixed to a bearing attached to base end (116) of cylinder assembly (110).
Rotating shaft (152) also defines a helical slot (155) extending from coupling end (158) towards free end (154). Helical slot (155) is dimensioned to receive pin (125). As seen in
It should be understood that since rotation of rotating shaft (152) relative to linear actuating assembly (120) is used to measure linear displacement of linear actuating assembly (120), there should be no accidental rotation about the axis defined by movement of linear actuating assembly (120) of rotating shaft (152) relative to linear actuating assembly (120). Accidental rotation of rotating shaft (152) relative to linear actuating assembly (120) could give a false reading of linear displacement along the axis defined by movement of linear actuating assembly (120). Therefore, attachment features (112, 126) need to rotationally fix cylinder assembly (110) and linear actuating assembly (120) relative to one another, along the axis defined by movement of linear actuating assembly (120), to prevent false readings. While in the current example, attachment features (112, 126) include pin eyes, any other suitable attachment features may be used as would be apparent to one having ordinary skill in the art.
Having linear displacement measuring assembly (130), or at least a portion of linear displacement measuring assembly (130) stored within cylinder assembly (110) and linear actuating assembly (120), may provide benefits of protecting linear displacement measuring assembly (130) from external moving parts, dust, and debris. Additionally, linear displacement measuring assembly (130) may be rigid for durability, as compared to known string potentiometers currently used.
B. Exemplary Vehicle Lift Assembly
Top plate (224) is secured to the top of side rails (222) by any suitable means such as welding, mechanical fastening, adhesive boding, etc. In the present example, top plate (224) is comprised of a thin sheet of a rigid material such as steel, iron, aluminum, composite, or the like. Top plate (224) is configured to support the load of a vehicle resting on runways (220). The load of a vehicle is also distributed by top plate (224) to runways (220), which provide additional structural rigidity.
Each runway (220) is positioned relative to the other a transverse distance that is approximately equivalent to the wheel track of a vehicle that is desired to be lifted. The transverse distance thus permits a vehicle's wheels to rest on top of runways (220). In some embodiments, runways (220) may include angled sloped ramps (not shown) or other features to facilitate rolling or driving a vehicle onto and off of runways (220). Of course, such a feature is entirely optional and may be omitted in other comments. Runways (220) may also include other features suitable to support a vehicle as will be apparent to one of ordinary skill in the art in view of the teachings herein. Some examples of additional and/or alternative features that may be incorporated into runways (220) and/or other features of lift system (200) are disclosed in U.S. Pat. No. 6,763,916, entitled “Method and Apparatus for Synchronizing a Vehicle Lift,” issued Jul. 20, 2004, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 6,059,263, entitled “Automotive Alignment Lift,” issued May 9, 2000, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 5,199,686, entitled “Non-Continuous Base Ground Level Automotive Lift System,” issued Apr. 6, 1993, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 5,190,122, entitled “Safety Interlock System,” issued Mar. 2, 1993, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 5,096,159, entitled “Automotive Lift System,” issued Mar. 17, 1992, the disclosure of which is incorporated by reference herein; and U.S. Pub. No. 2012/0048653, entitled “Multi-Link Automotive Alignment Lift,” published Mar. 1, 2012, the disclosure of which is incorporated by reference herein. It should be understood that that the teachings herein may be readily combined with the teachings of the various references cited herein.
As can be seen in
Mounting brackets (257) extend vertically from base plate (254). Mounting brackets (257) may be fixedly secured to base plate (254) by any suitable means such as welding, adhesive bonding, mechanical fastening, and/or the like. Alternatively, mounting brackets (257) may be integral to base plate (254). As can best be seen in
Mounting holes (258, 259) are positioned at each end of mounting bracket (257). In particular, a rear mounting hole (258) is positioned near the rear of mounting bracket (257), and a front mounting hole (259) is positioned near the front of mounting bracket (257). Rear mounting hole (258) is positioned vertically higher than front mounting hole (259). As will be understood in view of the description below, mounting holes (258, 259) are oriented such that linkage assembly (260) and actuation assembly (350) are operable to fold up, thus minimizing the height of vehicle lift system (200) when vehicle lift system (200) is in the retracted position as shown in
Turning to
As can be seen in
Elongated portions (266, 274) of lower links (262) are generally rectangular in shape. Alternatively, any suitable shape may be used, such as an elongated rod, elongated hexagon, hollow tubing, or the like. Rounded end portions (268, 276) are generally circular to accommodate bores (270, 278) and generally reduce the area occupied by rounded end portions (268, 276). In other examples, rounded end portions (268, 276) may have any suitable shape. Lower links (262) are relatively rigid and may be comprised of any suitable material such as steel, iron, aluminum, composite, or the like. Of course, lower links (262) may have any other suitable configuration and composition as will be apparent to those of ordinary skill in the art in view of the teachings herein.
Third armatures (282) are generally the same size and shape. In particular, each third armature (282) is approximately rectangular and includes a taper from one end to another. The front end of third armature (282) is wider relative to the rear end to accommodate two connecting bores (284, 285). As will be described in greater detail below, upper connecting bore (284) and lower connecting bore (285) are used to rotatably couple lower links (262) to third armatures (282) via pins (300, 302) respectively. As will also be described in greater detail below, connecting bores (284, 285) are positioned on third armature (282) to provide pivot points about which lower links (262) may pivot relative to third armature (282). The rear end of third armature (282) is rounded and includes an attachment bore (286). Attachment bore (286) is positioned to permit rotatable coupling between third armature (282) and runway (220) via pin (304) and pin blocks (not shown).
As can best be seen in
As mentioned above and shown in
Each hydraulic actuator assembly (100) is in electrical communication with control circuit (500) via communication wires (502). In the current example, communication wires (502) are connected to rotation sensor (140) of each hydraulic actuator assembly (100). Communication wires (502) may also be in electrical communication with other aspects of each lift assembly (250).
Communication wires (502) may be configured to provide electrical power from circuit board (500) to rotation sensor (140). Additionally, rotation sensor (140) may be able to communicate the rotational displacement of rotating element (142) relative to static element (148). As mentioned above, the rotational displacement of rotation element (142) relative to static element (148) corresponds to the linear displacement of linear actuating assembly (120) relative to cylinder assembly (110). Therefore, circuit board (500) may be configured to determine the linear displacement of linear actuating assembly (120) relative to cylinder assembly (110) through a predetermined formula based on dimensions of hydraulic actuator assembly (100). Additionally, the linear displacement of linear actuating assembly (120) relative to cylinder assembly (110) may correspond with a predetermined height of the portion of lift assembly (250) directly connected to runways (220) based on the dimensions of lift assembly (250). Therefore, circuit board (500) may be configured to determine the vertical height of the portion of lift assembly (250) connected to runways (220), or any other suitable portion of lift assembly (250) as will be apparent to one having ordinary skill in the art in view of the teachings herein.
Circuit board (500) is also in electrical communication with pump (400). Circuit board (500) may control the amount of hydraulic fluid that pump (400) distributes to individual hydraulic actuator assemblies (100). Therefore, circuit board (500) may control the individual heights of each hydraulic actuator assembly (100). For example, circuit board (500) may determine individual heights of each lift assembly (250) in order to determine the lowest lift assembly (250). Circuit board (500) may then calculate the difference of the heights of each of the other three lift assemblies (250) in order to equal the lowers lift assembly (250). Circuit board (500) may then communicate instructions to pump (400) in order to adjust the three, higher, lift assemblies (250) to lower accordingly to equalize the height of each lift assembly (250). Therefore, communication between linear displacement measuring assembly (130), circuit board (500), and pump (400) may help keep vehicle lift system (200) level.
Of course, utilizing the lowest lift assembly (250) as the datum point is just one option. Circuit board (500) could determine the highest lift assembly (250). Circuit board (500) may then calculate the difference of the heights of each of the other three lower lift assemblies (250) in order to equal the highest lift assembly (250). Circuit board (500) may the communicate instructions to pump (400) in order to adjust the three, lower, lift assemblies (250) to raise accordingly to equalize the height of each lift assembly (250). Any other suitable means of equalizing the height of each lift assembly (250) may be utilized as would be apparent to one having ordinary skill in the art in view of the teachings herein.
While in the current example, vehicle lift system (200) includes linkage assemblies, armatures, and pins, any other suitable vehicle lift system having a literature displacement measuring assembly (130) in communication with a circuit board (500) lift assembly (250).
Although actuation assembly (350) is shown as being hydraulically actuated, it should be understood that any suitable device may be used to actuate lift assembly (250). For instance, actuation assembly (350) may comprise a linear actuator having a lead screw and a motor, a pneumatic actuator, spring loaded actuator, or any other suitable actuator as will be apparent to those of ordinary skill in the art in view of the teachings herein.
The illustrated embodiment is double-acting; that is, it uses pressure fluid on both sides of plunger (124) in cylinder (102), and the pressure differential between the two sides moves plunger (124) axially through the cylinder (102). In alternative embodiments, cylinder (102) is single-acting, where there is fluid on only one side of the plunger (124) (e.g., between plunger (124) and head end (118)), and the other side of the plunger (124) (e.g., between plunger (124) and base end (116)) is air- or gas-filled or even vented. In such embodiments, fluid channel (105) is a breather that leads air in and out, and fluid channel (107) is a pressure line/return line.
