Original Pancake® Cylinder - FABCO-AIR - #4

9. Polishing the cylinder bore and piston rod produces a fine

crosshatched finish. This crosshatching provides minute oil ring type grooves for retaining lubrication. This finish, unlike an ultra smooth finish, provides a place for lubrication to lie and support the seal as it moves along the surface. The surface finish and lubrication provide lower friction and longer seal life.

10. The piston rod is centerless ground, polished, and hard chrome plated (68-72 Rc) stainless steel. Surface finish is 12 RMS or better and carries lubrication like our cylinder bore (see 9). These features combined with the low friction and high load capacity of the Duralon^®

bushing provide exceptional cylinder life. Female, fine pitch rod thread and wrench flats are standard.

11. A pilot diameter on the cover is concentric with the rod bushing and locates in the cylinder bore to maintain the concentricity, precision, and rigidity of the Pancake® design.

12. Counterbores on both sides of the piston maintain concentric­ity of piston rods to each other as well as to the piston ORing. This also provides complete axial and radial rigidity of the piston so that it cannot float or be pounded loose.

13. The piston rods are connected by a high strength stud, sandwiching the piston between the rod end faces. The assembly is torqued for proper preload of the stud and clamping of the piston head. Loctite® on the threads and faces assures sealing and locks the assembly against pounding and vibration. This procedure provides a positive and rigid assembly that will not allow the piston to float or be pounded loose.

14. The "T" Series has a thicker piston which incorporates a bearing strip in addition to the O-ring seal. This bearing strip is a close toler­ance, rectangular cross section strip of a tough, stable, wear resistant PTFE compound. If the piston rod assembly is forced off center by misalignment or other forces, this bearing, along with the long and rigid Duralon^® rod bushing, supports the load and helps to maintain the long life of the cylinder bore and O-ring seal. Note: the bearing is not included, or required in double rod models because the long rod bushings at each end of the cylinder provide superb support.

15. Two guide pins of precision ground tool steel pass through the piston head. These guide pins prevent rotation of the rod with a tolerance of ±1°. Note that the guide pins are located internally. This provides protection from the environment and from physical damage. Lubrication is provided with other internal parts. NO additional space is required and the rod end is left free for attachments and tooling as required by the application. An information label, similar to this one, is applied to each cylinder to warn against damage.

1. The heavy wall prohibits any damage to the bore from external forces.

2. The one piece cylinder body and bushing support end is machined from solid aluminum bar-stock. This provides unequalled strength, rigidity, and piston rod support. Machining all surfaces provides per­pendicularity and concentricity for locating, mounting, and making attachments to the rod. It also presents a clean, smooth, "no-dirt-catching" appearance on your machine.

3. Unique construction provides unequalled piston rod support and

prohibits "Blowout"! The one piece Duralon® rod bushing is inserted from the inside and then staked in place. Duralon® is a Teflon® lined fiberglass structure with a load carrying capacity of 60,000 psi. Compare capacity with Nylon® at 1,000 psi, porous bronze at 4,500 psi, and porous iron at 8,000 psi. Duralon also provides: CONSIS­TENCY, reliable and predictable performance from bushing to bushing; CORROSION RESISTANCE, nonmetallic materials resist galvanic, chemical and fretting corrosion; SELF LUBRICATION, Teflon® lin­ing provides low friction and minimizes stickslip, even under no-lube conditions; SEIZURE RESISTANCE, fiberglass backing material will not seize or gall on shaft under extreme wear. Generally the bearing length is increased as the stroke increases, providing even more piston rod support.

4. Internally lubricated Buna-N O'Rings (-25° to + 250°F) provide low profile, low friction, and long life sealing of piston and rod. All static seals are Buna-N.

These dynamic O'Rings are compounded to provide extra long wear and lower breakaway (starting) and running friction and smoother operation. In tests, cylinders with internally lubricated O'Rings have extended cycle life two to three times beyond cylinders with standard Buna-N seals. The chart below shows maximum breakaway or start­ing pressure to extend the rod of single rod, double acting (Action -X) cylinders with internally lubricated O'Rings under no-load conditions after 3 days delay at zero pressure. With other actions and/or combina­tions of options, breakaway pressures may vary.

Bore Number 5 7 121 221 321 521 721 1221 Bore, Inches 1/2 3/4 1-1/8 1-5/8 2 2-1/2 3 4 Breakaway psi 12.0 6.5 4.5 4.5 4.0 3.0 3.0 2.5

These low operating pressures allow for the use of vacuum as an Operating Media in many applications. 1.0 psi is the equivalent of 2.04"

Hg of vacuum. To determine the force output of a cylinder with vacuum, multiply: Force Area of cylinder x inch Hg vacuum x 0.49 = Force, lb.

5. The thinnest possible piston and rear cover design keeps the overall height as short as possible. Please note that any cylinder offering less height than that of a Pancake® with the same stroke, sacrifices rod bushing length and/or overall strength.

6. The aluminum cover is held in place with multiple plated screws for strength, rigidity, ease of modification for specific application require­ments, and ease of access for maintenance should it be required.

7. The aluminum piston is attached to the piston rod with a socket flat head cap screw which is torqued for proper preload on the screw and clamping of the piston. Loctite® on the threads and faces assures sealing and locks the assembly against pounding and vibration.

8. The piston in all bores has a counterbore for piston rod location and control of concentricity between piston rod and piston O.D.

THIS CYLINDER HAS A NONROTATING ROD.

TO PREVENT INTERNAL DAMAGE HOLD ROD BY WRENCH

FLATS WHEN INSTALLING OR REMOVING ATTACHMENTS

16. The guide pins pass through Polyurethane ORing seals and SAE660 bearing bronze bushings incorporated in the piston head.This combination provides no leak, precision guiding and long life.

18. A disk of rubber is included at the end of the guide pins to take up play and firmly seat the pins in the precision machined guide pin holes.

19. Integral rod bearing and endcap is hard anodized aluminum. The piston rod seal O-ring is located as close to the outer end as feasible so that as much of the bearing as possible gets system lubrication as well as protecting most of the bearing length from the environment. A precision machined pilot diameter locates the cylinder bore to assure concentricity and proper rod alignment.