Winch Crab Single/Double Purchase Manufacturer,Supplier and Exporter in India
Product Code : EL-AMLE-8947
Jlab Export is a leading Winch Crab Single/Double Purchase Manufacturer,and suppliers in India
Winch Crab Single/Double Purchase (code EL-AMLE-8947) is a geared lifting machine for finding velocity ratio, mechanical advantage and efficiency, built on heavy cast iron wall brackets with a grooved wheel of 25 cm diameter and machine-cut gears. The single purchase model has one gear pair, while the double purchase version carries a double set of gearing. Both versions of the winch crab are made by JLab in Ambala, India.
Specifications
| Parameter | Detail |
|---|---|
| Versions | Single purchase or double purchase |
| Grooved wheel | 25 cm diameter |
| Gears | Machine cut |
| Mounting | Heavy cast iron wall brackets |
| Double purchase | Double set of gearing; otherwise as the single purchase |
| Quality check | Each winch crab is visually inspected before dispatch |
| Pack quantity | Each (sold individually) |
| Minimum order quantity | 1 unit |
| Dispatch time | Usually 14–18 working days |
| Product code | EL-AMLE-8947 |
| Manufacturer | Jain Laboratory Instruments Pvt Ltd (JLab) — OEM |
| Country of origin | India (made in Ambala, Haryana) |
Velocity Ratio, Mechanical Advantage and Efficiency
The effort P acts on a wheel of diameter D while the rope on a load drum of diameter d raises the load W. For the single purchase, VR = (D/d) × (T2/T1), where T1 is the number of teeth on the pinion and T2 on the spur wheel it drives. Mechanical advantage is W/P and efficiency η = MA/VR. Readings of P at several loads give the law of the machine, P = mW + C, and a limiting efficiency of 1/(m × VR).
Single or Double Purchase?
The double purchase adds a second pinion and spur wheel between the effort shaft and the load drum, so its velocity ratio becomes (D/d) × (T2/T1) × (T4/T3). A far heavier load can then be raised by the same effort, at the cost of more effort movement for each unit of lift and the friction of one more gear pair, which usually brings the efficiency below that of the single purchase. Testing both shows how gearing trades speed for force.
Other Lifting Machines and Gear Apparatus
- Wall Mounted Screw Jack — load raised by a screw, with square and V threads compared.
- Gear Trains Apparatus — bench set of four gear sizes plus an arm for simple epicyclic gearing.
- Wheel and Axle — two wooden wheels on a metal stand showing simple-machine equilibrium.
More lifting and friction rigs are grouped in Applied Mechanics Lab Equipments under Mechanical Engineering Lab Equipment.
Request a Quote
For a quotation, state single or double purchase, the quantity and the delivery address through Add To Cart or the contact page.
Last updated: 30 October 2026
