Fully Motorized Prostak Stacker
(2000# to 6,000# Capacity Models)
Standard Specifications

Electric Chain Hoist:
  • Meets requirements of ASME, OSHA, ISO, CE and entire hoist is listed by UL and C-UL
  • Nema 3R aluminum hoist enclosure
  • Upper and lower control circuit limit switches30 minute duty motors with H4 duty classification and class F insulation
    AC brake with a LIFETIME GUARANTEE on all the steel brake discs
  • 150% overload protection by use of a slip clutch on the first stage gearing
  • Five pocket load chain wheel for smoother lifting and longer chain life
  • Two layer zinc plated load chain with 10% elongation to resist corrosion and absorb shock loading
  • Dual speed models with 4, 5 or 6 to 1 high to low speed ratios for easier, safer and more accurate positioning
  • Easily serviced with gearing under one end cover and all electrical components and brake under the other
  • Grease lubrication is less likely to leak and eliminates oil level checks
  • 4,400# capacity hoist @16/4 fpm used for 2,000# capacity stacker crane
  • 6,600# capacity hoist @ 16/3 fpm used for 4,000# capacity stacker crane
  • 8,800# capacity hoist @ 16/4 fpm used for 6,000# capacity stacker crane

Controls:

  • Standard controls used for trolley, rotation, and bridge motions are 2 step infinitely variable frequency controls
  • Variable frequency drives (VFD’s) allow for precise positioning, thereby reducing damage to pallets, product, etc.
  • The ramp up and ramp down features of these controls eliminate high impact forces on the motor gearboxes and rotation pinion gears
  • The controlled acceleration and deceleration eliminates occurrences of wheel slippage thus promoting extended wheel and rail life
  • The ramp down or “dynamic braking” function of the VFD’s act as the main braking mechanism while the motor brake acts only as a parking brake
  • Motor brake adjustments and component wear and failure are virtually eliminated because the braking is done electronically and at a controlled deceleration rate
  • VFD’s also provide thermal overload protection for the gear/brake motors
  • Bridge enclosure (Nema 4/12) includes IEC rated mainline and brake contactors, branch circuit fusing, and wires are marked at both ends

Trolley & Bridge Drive Wheel Assemblies:

  • Utilize anti-friction sealed bearings which are lubricated for life
    Wheels are a spheroidal graphite cast iron, a material with a self lubricating effect which results in a high resistance to wheel and rail wear
  • Wheels are double flanged with rotating axle drive arrangement, therefore, the gearing, etc. is totally enclosed and not subject to the environment which prolongs the life of the equipment
  • Wheel hubs and shafting are splined which transmit torque better and last longer than arrangements that use keyed shafts
  • Motors are helical geared, fan-cooled(TEFC), inverter duty rated with a finned housing (for better temperature control) and include DC disc brakes

Bridge Assembly:

  • Designed using wide flange girders and high strength steel bar(bridge rail)
  • The bridge design meets or exceeds CMAA specification number 70
  • The power and control festooning is run using a tray supported cable track system to keep the festooning from interfering with the forks and/or lifted product
  • Bridge buffers are made of cellular foam plastic for max energy absorption

Trolley Assembly:

  • Consists of structural tubing and gusseted bottom plate for maximum rigidity and to prevent binding of the rotation bearing
    Machined bearing, wheel connection, and rotation drive frame surfaces for proper alignment and also prolongs the life of the trolley components
  • Special bearing with special hole pattern, inner race, and seals to provide a smooth and bind free rotation
  • Rotation drive is a helical geared, fan-cooled(TEFC), inverter duty rated gear motor with a finned housing
  • Rotation drive arrangement includes a slip clutch assembly to protect gearing from shock loads if the mast or forks are driven into the rack, or other rigid obstruction
  • The trolley is fitted with four sets of anti-kick up assemblies to prevent trolley derailment in the event that the mast is run into a rigid aisle obstruction
  • Trolley buffers are made of cellular foam plastic for max energy absorption

Mast Assembly:

  • Designed using structural channels or beams with horizontal braces and high strength steel guide bar(carriage track)
  • The carriage track is designed and manufactured to a ±1/16” tolerance for maximum load stability
  • The top connection plate is machined for proper alignment and to prevent binding of the rotation bearing
  • Includes detachable pendant assembly at control console which can be used either attached to the mast or disconnected from the pendant clip to allow the operator a better view of the storage levels, thereby allowing easier positioning of the pallet/load into or out of the rack
  • Includes a 90 watt flood light mounted to the mast which rotates with the load
    Includes a collector ring to provide 360° continuous rotation and includes a pin connector type plug to connect to trolley junction box for easy installation
  • Standard safety features include:
    • Adjustable toe guard
    • Control console protective hand guards
    • Mast mounted back stop (to protect operator from pinning him/herself between the crane and rack)
    • Overhead protective canopy
    • Steel mesh guarding from the bottom of mast to the bottom of the control console
    • Polycarbonate operator window(shatter and abrasion resistant) three panels high starting at the control console
    • Pendant with keyed on/off switch and supplied with a spare key

Fork Carriage Assembly:

  • Consists of a machined weldment which ensures proper cam follower and fork alignment
  • Includes four main cam followers and four guide rollers all with sealed bearings
  • An integrated anti-free fall safety mechanism restrains a loaded carriage within a fraction of an inch in an unlikely event of chain failure (simply move carriage up to unlock)
  • Class II carriage bars and forks are used for capacities up to 4,000 lbs.
  • Class III carriage bars and forks are used for capacities over 4,000 lbs.
  • Forks are manually adjustable for varying pallet and/or fork pocket centers

Runway Electrification:

  • Four double shoe type collectors are provided with a collector post mounted to the bridge
  • The conductor bar system is a 110Amp 4-bar system (3-power & 1-ground)