1. Technical Field
The present disclosure relates to elevation mechanisms, and particularly, to an elevation mechanism utilizing a scissor lift support.
2. Description of the Related Art
Elevation mechanisms have been widely used in many applications for many years, such as, or example, elevating automobiles, building components, supplies, structural components, scaffolding, work stands, patient beds and many others.
A commonly used elevation mechanism includes a base assembly, a platform, and a scissor lift assembly movably interconnecting the base assembly and the scissor lift assembly. The base assembly includes a support member, a threaded rod and a threaded member. The threaded rod is fixed on the support member. The threaded member sleeves on the threaded rod. The scissor lift assembly includes a scissor support and a wheel. The scissor support includes a first scissor leg and a second scissor leg pivotedly attached to the first scissor leg in a middle portion. The wheel is pivotedly connected to an end of the first scissor leg. The threaded member is pivotedly connected to the other end of the first scissor leg. The platform and the support member are correspondingly pivotedly connected to opposite ends of the second scissor leg. The platform defines a retaining groove to receive the wheel. When the threaded rod is rotated in a clockwise direction, the threaded member slides the threaded rod to toward the end of the second scissor leg. An angle of the first scissor leg relative to the second scissor leg is increased, such that the scissor lift assembly raises the platform. When the threaded rod is rotated in a counterclockwise direction, the threaded member slides the threaded rod away from the end of the second scissor leg. An angle of the first scissor leg relative to the second scissor leg is decreased, such that the scissor lift assembly lowers the platform. However, the support center of the platform deviates to an edge of the platform as the wheel slides toward the edge of the platform, such that a heavy load cannot be stably supported on the platform.
Therefore, there is room for improvement within the art.
The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout several views, and all the views are schematic.
Referring to
Referring to
Each support member 11 includes a base 113 and a connecting portion 115. The connecting portion 115 extends from a middle portion of a side surface of the base 113 outward. The base 113 defines two through holes 1131 and two slots 1132 in opposite ends of the base 113. The two slots 1132 communicate with the corresponding through holes 1131. The connecting portion 115 defines a stepped hole 1151 in a middle portion of the connection portion 115.
The threaded rod 12 includes a main body 121 and two threaded portions 123,124. The two threaded portions 123,124 are formed at opposite ends of the main body 121. Rotation in a forward direction of the threaded portion 123 is opposite to that of the threaded portions 124. The two threaded members 13 threadedly engage with the corresponding threaded portions 123,124.
Each sleeve 15 includes a barrel portion 151 and a fixing portion 152. The fixing portion 152 connects an end of the barrel portion 151.
Each sliding member 16 includes a baseplate 161 and two connecting portions 162. The two connecting portions 162 are fixed to opposite ends of a side of baseplate 161. The threaded member 13 is fixed to the baseplate 161 between the two connecting portions 162. Each connecting portion 162 defines a through hole 1621 in a middle portion of each connecting portion 162. Each connecting portion 162 further defines a gap 1622 in an end of each connecting portion 162. The gap 1622 communicates with the through hole 1621. The sleeves 15 are received in the guide rods 14 in the corresponding through holes 1621 of the sliding member 16.
Referring to
Each scissor support 21 includes two first scissor legs 212, a second scissor leg 214, and a pivotal shaft 216. The second scissor leg 214 is positioned between the two first scissor legs 212. The pivotal shaft 216 passing through a middle portion of one of the first scissor legs 212, the second scissor leg 214, and the other first scissor leg 212 in that order. The outermost first scissor legs 212 of the scissor lift assembly 20 are correspondingly pivotedly connected to one of the first connecting members 22 and one of the second connecting members 23. The outermost second scissor legs 214 of the scissor lift assembly 20 are correspondingly pivotedly connected to the other first connecting members 22 and the other second connecting members 23.
Each first connecting member 22 includes a fixing portion 221 and a connecting portion 223. The connecting portion 223 extends from a middle portion of the fixing portion 221 outward. The fixing portion 221 defines a plurality of the stepped holes 2213 and two positioning steps 2215. The stepped holes 2213 are defined in a side of the fixing portion 221 at two sides of the connecting portion 223. The two positioning steps 2215 are defined in opposite ends of the other side of the fixing portion 221 adjoining the side defining the stepped holes 2213. The connecting portions 223 are pivotedly connected to free end of the first outermost scissor leg 212.
Each second connecting member 23 includes two fixing portions 231 and a connecting portion 233. The two connecting portions 233 extend from a middle portion of the fixing portion 231, and are spaced from each other. The fixing portion 231 defines a plurality of the stepped holes 2313 and two positioning steps 2315. The stepped holes 2313 are defined in the side of the fixing portion 221 at two sides of the connecting portion 233. The two positioning steps 2315 are defined in opposite ends of the other side of the fixing portion 231 adjoining the side defining the stepped holes 2213. The connecting portions 233 are pivotedly connected to free end of the outermost second scissor leg 214.
Each fixing member 24 includes a base 242 and two positioning portions 244. The two positioning portions 244 extend from a side of the base 242, and are spaced apart at the two ends of a side of the base 242. The two positioning portions 244 of one fixing member 24 engage with the corresponding positioning steps 2215 of the first connecting member 22. The two positioning portions 244 of other fixing member 24 engage with the corresponding positioning steps 2315 of the second connecting member 23.
Each spring 25 is substantially cylindrical, and is partially received in the respective stepped hole 2213 of the first connecting member 22 or the respective stepped hole 2313 of the second connecting member 23.
Referring to
Each sleeve 32 includes a barrel portion 321 and a fixing portion 323. The fixing portion 323 connects the barrel portion 321. Each sliding member 33 defines two through holes 331 in opposite ends of the corresponding sliding member 33. The barrel portions 321 are received in the corresponding through holes 331 of the sliding members 33. Each fixing member 34 defines two fixing holes 341 and two slots 342 in opposite ends of the corresponding fixing member 34. The two slots 342 communicate with the corresponding through holes 341.
In the illustrated embodiment, the drive device 50 is an actuator motor. The drive device 50 is pivotally connected to and rotates the threaded rod 12.
Referring to
Two threaded portions 123, 124 of the threaded rod 12 are first sleeved with the threaded members 13. The two guide rods 14 are then correspondingly sleeved with the corresponding sleeves 15. The two ends of the two guide rods 14 are fixed in the corresponding through holes 1131 of the two support members 11. The two ends of the threaded rod 12 are received in the corresponding stepped holes 1151 of the two support members 11. The baseplates 161 of the two sliding members 16 are fixed to the corresponding threaded members 13. The connecting portions 162 of the two sliding members 16 sleeved the corresponding sleeves 15.
The plurality of scissor supports 21 are pivotedly connected to one another. The two first connecting members 22 are correspondingly pivotedly connected to free end of the outermost first scissor legs 212 of the scissor lift assembly 20. The two second connecting members 23 are correspondingly pivotedly connected to free end of the outermost second scissor legs 214 of the scissor lift assembly 20. Some of the fixing shafts 26 correspondingly pass through the lowermost first connecting member 22 of the scissor lift assembly 20, the springs 25, and the fixing member 24. The other fixing shafts 26 correspondingly pass through the lowermost second connecting member 23 of the scissor lift assembly 20, the springs 25, and the fixing member 24. The lower ermost first and second connecting member 22,23 of the scissor lift assembly 20 can be slid relative to the fixing members 24, and resist the springs 25.
The two pairs of sleeves 32 are sleeved with the corresponding sliding rods 31. The two sliding members 33 are sleeved with the corresponding sleeves 32. The two ends of the two sliding rods 31 are fixed in the corresponding fixing holes 341 of the two fixing members 34.
Finally, the two fixing members 24 of the scissor lift assembly 20 are fixed to the corresponding sliding members 16 of the base assembly 10. The two sliding members 33 of the sliding assembly 30 are correspondingly fixed to the uppermost first and second connecting member 22,23 of the scissor lift assembly 20. The platform 40 is fixed to the two fixing members 34 of the sliding assembly 30.
When the drive device 50 rotates the threaded rod 12 in a clockwise direction, the two threaded members 13 slide the threaded rod 12 toward each other. An angle of the first scissor leg 212 relative to the second scissor leg 214 of the scissor lift assembly 20 is decreased, such that the scissor lift assembly 20 raises the platform 40. When the drive device 50 rotates the threaded rod 12 in a counterclockwise direction, the two threaded members 13 slide the threaded rod 12 away from each other. The angle of the first scissor leg 212 relative to the second scissor leg 214 of the scissor lift assembly 20 is increased, such that the scissor lift assembly 20 lowers the platform 40.
The sliding members 33 can be slid toward or away from each other, such that the support center of the platform 40 does not deviate when supporting heavy loads. In addition, the threaded rod 12 includes two threaded portions 123,124 engaging with the two threaded members 13, which in turn drive the scissor lift assembly 30 to lift more quickly. The springs 25 on the corresponding fixing shafts 26, resist the corresponding fixing members 24, and thus provide a resilient buffering force to the scissor lift assembly 20.
It is to be understood that the guide rods 14, the sleeves 15 and the sliding members 16 can also be omitted, wherein the first scissor leg 212 and the second scissor leg 214 at the bottom of the scissor lift assembly 20 are pivotedly connected to the corresponding threaded members 13. The sliding members 33 can also be omitted, wherein the first scissor leg 212 and the second scissor leg 214 at the top of the scissor lift assembly 20 are pivotedly connected to the corresponding sleeves 32. The first connecting members 22 can also be the same as the second connecting members 23, in which case the scissor support 21 includes same numbers of first scissor leg 212 and second scissor leg 214. Sliding rod 31 can also be only singular, wherein the number of sleeves 32 is two.
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Finally, while the present disclosure has been described with reference to particular embodiments, the description is illustrative of the disclosure and is not to be construed as limiting the disclosure. Therefore, various modifications can be made to the embodiments by those of ordinary skill in the art without departing from the true spirit and scope of the disclosure as defined by the appended claims.
Number | Date | Country | Kind |
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200910305539.7 | Aug 2009 | CN | national |