Hydraulic Thumbs
AMI hydraulic thumbs work against the bucket to grip, lift and place material such as brush, logs, poles, boulders and debris. The line has three main designs for excavators and loader backhoes: Stick Pivot, Progressive Link and Extreme Service Stick Pivot. A Hydraulic Weld On Thumb is also part.
About the Hydraulic Thumbs
AMI hydraulic thumbs work against the bucket to grip, lift and place material such as brush, logs, poles, boulders and debris. The line has three main designs for excavators and loader backhoes: Stick Pivot, Progressive Link and Extreme Service Stick Pivot. A Hydraulic Weld On Thumb is also part of the line.
On Stick Pivot thumbs, the thumb rotates on the same pivot point as the bucket pin, not on a separate weld-on pivot. The hydraulic cylinder connects directly to the thumb and covers 65 to 75 percent of bucket rotation. Because thumb and bucket turn on the same axis, the thumb tip and bucket teeth keep a constant grip on the load while rotating, with no scraping or slippage. Spherical bushings let the thumb flex on awkward loads without stressing the cylinder seals, and a cushioning cylinder softens the end of the stroke so the thumb retracts without a hard stop or machine shake.
The Progressive Link Thumb uses extra linkage to rotate more than 180 degrees and keep pressure more constant through the whole cylinder range. It can reach objects close to the machine and keeps its grip across the bucket's full rotation, including at full roll out. The Extreme Service Stick Pivot is the heavier stick pivot build for excavators from 24,000 to 115,000 lbs, with 2 to 5 tines and widths from 11 to 55 inches. The Hydraulic Weld On Thumb folds tight to the stick when not in use, has serrated tines for grip, and comes in multiple widths and lengths to match different coupler and bucket setups.
Features
- Stick Pivot thumbs rotate on the bucket pin axis, so thumb tip and bucket teeth keep a constant grip through rotation
- Cylinder covers 65 to 75 percent of bucket rotation on Stick Pivot models
- Spherical bushings let the thumb flex on awkward loads without adding stress to the cylinder seals
- Cushioning cylinder softens the end of the stroke and reduces machine shake
- Progressive Link thumb rotates more than 180 degrees and holds pressure across the full bucket rotation
- Extreme Service Stick Pivot models with 2 to 5 tines and widths from 11 to 55 inches
- Weld-on thumb folds tight to the stick and has serrated tines for grip
Models: Stick Pivot Hydraulic Thumb (loader backhoe model families LBTH0610HSP, LBTH1214HSP and LBTH1416HSP, in 2-tine and 4-tine versions), Progressive Link Hydraulic Thumb, Extreme Service Stick Pivot Hydraulic Thumb (THXS model family) and Hydraulic Weld On Thumb. Fast Track models are shown in the spec tables for the Stick Pivot and Extreme Service Stick Pivot thumbs.
Specifications
| Stick Pivot Thumb machine class (loader backhoe) | Class 30, 50 and 70 |
| Stick Pivot Thumb widths (loader backhoe models) | 7 - 28 inches |
| Extreme Service Stick Pivot Thumb machine class (excavator) | 24,000 - 115,000 lbs (categories 130-400) |
| Extreme Service Stick Pivot Thumb widths | 11 - 55 inches |
| Progressive Link Thumb rotation | More than 180 degrees |
Gallery
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