1-4. DIFFERENCES BETWEEN MODELS AND SIZES. The main differences between hoist models are in the service classification, type of load chain and the suspension employed.
These are described in paragraphs (a) through (d), below. The differences between sizes of hoists are in the number of gear reductions used and the reeving of the load chain. Two-reduction gearing is used for 1/4 through 1/2 ton rated load hoists; threereduction gearing for 1, 2 and 3 ton rated hoists. On 1/4 through
1 ton rated load hoists, the load chain is single reeved (one part of chain); on 2 ton rated loads, the chain is double reeved
(two parts of chain); on three ton rated loads, the chain is triple reeved (three parts of chain).
a. Coil type chain is full-flexing electric welded link chain. It is especially designed for use in Yale Electric Hoists and only factory approved chain of the correct size, pitch, hardness, and strength can be used with these hoists.
b. Suspension differences include a conventional hook type mounting and a lug type mounting. Hook suspension allows portability permitting hoist to be easily moved from job to job.
Lug suspension permits hoist to be rigidly mounted to overhead structure or attached to Yale Rigid Mount Trolleys, affording unusual headroom advantage.
c. Some hoists are adaptations of standard model hoists to permit use in some mildly corrosive atmospheres, high ambient temperatures and high duty cycle operation. They are available in either hook or lug suspension. Construction variations from standard models are as follows:
(1) Load chain is zinc plated for corrosion resistance.
(2) All exposed aluminum parts are prime painted with corrosion resistant paint.
(3) Aluminum castings are specially treated.
1-5. OVERLOAD CLUTCH. Yale Electric Hoists are equipped with an overload clutch that is designed to help guard against excessive overloads. It is a cone-friction clutch that connects the first reduction gear to the clutch pinion shaft. A belleville disc spring provides clutch pressure between the gear and its cone shaped gear center. An excessive overload causes the gear to rotate without turning the gear center and pinion shaft.
See paragraph 3-5 for operation.
WARNING
THE OVERLOAD CLUTCH IS A PROTECTIVE DEVICE
THAT WILL PERMIT OPERATION OF YOUR HOIST
WITHIN ITS RATED LOAD AND WILL PREVENT LIFTING
OF EXCESSIVE OVERLOADS WHICH CAN CAUSE
PERMANENT DEFORMATION OR WEAKENING OF A
PROPERLY MAINTAINED HOIST AND/OR ITS
SUSPENSION.
2-2. INSTALLATION.
NOTICE
Lubricate load chain before operating hoist. See paragraph
4.3
a. On hook suspended hoists, select a suitable overhead support in area hoist is to be used (one capable of holding weight of hoist and its rated load) and hang up hoist. Be certain upper hook is firmly seated in center of hook saddle. Upper hook is equipped with a spring type hook latch; it may be necessary to remove latch to attach hook to support. Replace latch after hoist is installed.
b. On lug suspended hoists, select a suitable overhead support in area hoist is to be used (one capable of holding weight of hoist and its rated load). Mount hoist using through bolts, of appropriate size, to fit mounting holes in suspension lug at top of hoist frame. (See table below.) The structure used to suspend hoist must be of sufficient strength to withstand reasonable forces to which hoist and support may be subjected. Hoist must be aligned with load to avoid side pulls.
c. On lug suspended hoists, the suspension lug is factory oriented to cross mount the hoist. This is the recommended orientation. To rotate the lug 90
°
for parallel mounting, follow instructions below:
(1) On 1/4 through 1 ton hoists, remove the two screws securing the anti-rotation bracket and remove the bracket. Rotate the suspension lug in 90
°
increments. Reinstall the anti-rotation bracket and secure with two screws and lock washers.
(2) On 2 ton hoists, remove hex socket head screw in lower lock plate. Remove lower lock plate. Rotate suspension lug to selected position and replace lock plate and hex socket head screw.
(3) On 3 ton hoists, the hanger bracket must first be removed from the hoist to provide access to suspension nut per Section
VII, par. 7-2. a. (4) and figures 7-2 and 7-3. To remove lug bolt, follow instructions in Section VII, par. 7-3. b. (3). With bolt removed lift lug from hanger and reposition as desired. The lug is located and prevented from turning by integral lugs on adjacent surfaces of the lug and the hanger. Reinstall suspension bolt, spherical washers and nut. Align hole in nut and suspension bolt. Reassemble hanger bracket to hoist.
d. On rigid mount trolley suspended hoists, the trolley side plates must be properly spaced so trolley will fit I-beam on which hoist will operate. Adjustment for various I-beam sizes is accomplished by rearrangement of spacer washers on through bolts which connect trolley side plates to suspension lug on hoist. Refer to instruction sheet furnished with Yale Rigid Mount
Trolleys for complete instructions.
SECTION II - INSTALLATION
2-1. GENERAL. Yale Electric Hoists are completely lubricated and load tested under their own power before being shipped from the factory. To place hoist in service, attach to suitable overhead suspension (par. 2-2) in area to be used; make preinstallation check (par. 2-3); and connect to the proper power supply (par 2-4).
SUSPENSION LUG BOLT SIZES AND SPACING
Hoist
Rated Load
(tons)
1/4, 1/2 &1
2
3
Bolt Diameter
(in)
5/8
1
1-1/4
Distance
Between Holes
(in)
3-1/8
5
6
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