Mason Industries Neoprene Floor Mount Vibration Isolators

Neoprene Mounts

Up until the 1950s most rubber mountings were designed to take the load in shear. Mountings were circular or sold in long strips, so the capacity could be controlled by size and durometer, or durometer and the cut off length.

Shear loading curves are straight line similar to steel springs. The deflection can be used directly in the frequency equation after dynamic stiffness correction. Unfortunately, shear mountings could and did fail because of bond failure between the rubber and metal. When overloaded, the mountings would bottom out. Compression mountings are less expensive for a given capacity and when overloaded, there is still a cushion. When loaded conservatively, the load deflection curve is similar to the straight line shear.

The general configuration of our N mountings was known, but all mountings were manufactured as at the right and seldom taller than 1″. Both the base plate and the upper tapped washer were exposed and they corroded. As foolish as it seems now, Mason Industries cemented a rubber pad to the baseplate to provide friction. Since greater efficiency can only be accomplished by increasing deflection, when double deflection was needed, two mountings were bolted together. This was another makeshift arrangement.

The definition of a rubber isolation mounting is any configuration, round, square or rectangular with a known capacity and deflection. Acoustical solutions are in the 6 8 Hz frequency range. However, these very same low stress isolators can be stacked with steel shim plates between to achieve lower frequencies for vibration isolation. This grouping is typical of special purpose product.

Neoprene mounts are better isolators than isolation pads because they are thicker (taller) and provide more deflection. Top bolts and washers are provided for bolting to the equipment. The neoprene friction covering on the bottom generally eliminates bolting to the structure. These excellent all-purpose oil resistant mountings are used under compressors, blowers, air conditioning equipment, pumps, machine tools, transformers, etc. Used in compression only.

Specifications:

Part Number 35-275-7 35-276-5 35-277-3 Type ND-A ND-A ND-A Capacity Range (LBS.) 15 – 45 40 – 75 60 – 125 Deflection Range (in.) 0.20 – 0.40 0.20 – 0.40 0.20 – 0.40 D 1-1/4″ 1-1/4″ 1-1/4″ Height (H) 1-1/2″ 1-1/2″ 1-1/2″ L 3-3/16″ 3-3/16″ 3-3/16″ T 3/16″ 3/16″ 3/16″ Width (W) 1-5/8″ 1-5/8″ 1-5/8″ Mounting Hole Distance (BC) 2-3/8″ 2-3/8″ 2-3/8″ Cap Screw Diameter & Length (CS) 5/16-18 x 3/4″ 5/16-18 x 3/4″ 5/16-18 x 3/4″ MBD 5/16″ 5/16″ 5/16″ Size (Color Mark) Black Green Red Part Number 35-278-1 35-279-9 35-280-7 35-281-5 Type ND-B ND-B ND-B ND-B Capacity Range (LBS.) 85 – 175 125 – 250 190 – 380 300 – 600 Deflection Range (in.) 0.25 – 0.50 0.25 – 0.50 0.25 – 0.50 0.25 – 0.50 D 1-3/4″ 1-3/4″ 1-3/4″ 1-3/4″ Height (H) 1-7/8″ 1-7/8″ 1-7/8″ 1-7/8″ L 3-7/8″ 3-7/8″ 3-7/8″ 3-7/8″ T 1/4″ 1/4″ 1/4″ 1/4″ Width (W) 2-5/16″ 2-5/16″ 2-5/16″ 2-5/16″ Mounting Hole Distance (BC) 3″ 3″ 3″ 3″ Cap Screw Diameter & Length (CS) 3/8-16 x 1″ 3/8-16 x 1″ 3/8-16 x 1″ 3/8-16 x 1″ MBD 5/16″ 5/16″ 5/16″ 5/16″ Size (Color Mark) Green Red White Yellow Part Number 35-282-3 35-283-1 35-284-9 Type ND-C ND-C ND-C Capacity Range (LBS.) 275 – 550 375 – 750 550 – 1100 Deflection Range (in.) 0.25 – 0.50 0.25 – 0.50 0.25 – 0.50 D 2-9/16″ 2-9/16″ 2-9/16″ Height (H) 2-3/4″ 2-3/4″ 2-3/4″ L 5-1/2″ 5-1/2″ 5-1/2″ T 1/4″ 1/4″ 1/4″ Width (W) 3-5/16″ 3-5/16″ 3-5/16″ Mounting Hole Distance (BC) 4-1/8″ 4-1/8″ 4-1/8″ Cap Screw Diameter & Length (CS) 1/2-13 x 1″ 1/2-13 x 1″ 1/2-13 x 1″ MBD 1/2″ 1/2″ 1/2″ Size (Color Mark) Red White Yellow Part Number 35-285-6 35-286-4 Type ND-D ND-DS Capacity Range (LBS.) 1150 – 2300 2150 – 4300 Deflection Range (in.) 0.25 – 0.50 0.25 – 0.50 D 3-3/8″ 3-3/8″ Height (H) 2-3/4″ 2-3/4″ L 6-1/4″ 6-3/4″ T 5/16″ 5/16″ Width (W) 4″ 4-3/8″ Mounting Hole Distance (BC) 5″ 5-1/2″ Cap Screw Diameter & Length (CS) 1/2-13 x 1″ 1/2-13 x 1″ MBD 1/2″ 1/2″ Size (Color Mark) Yellow Yellow