HELMET WITH SLIP PLANE SYSTEM
A helmet may have an inner liner forming a body of the helmet, the inner liner having a concave inner surface defining a cavity configured for receiving a wearer's head. A plurality of slippage pads are disposed at selected locations on the concave inner surface and connected to the inner liner, the slippage pads having an elongated shape with a length and a width, the length being greater than the width, the slippage pads each defining a number of integrally connected side-by-side tubes each having an opening adapted to be oriented toward the wearer's head, the openings aligned longitudinally along the length of the slippage pads. A plurality of projecting cushioning pads are disposed adjacent to the slippage pads, and have a greater height than the slippage pads and exhibiting a greater deformability than the slippage pads.
1 . A helmet comprising:
at least an inner liner forming a body of the helmet, the inner liner having a concave inner surface defining a cavity configured for receiving a wearer's head;
a plurality of slippage pads disposed at selected locations on the concave inner surface and connected to the inner liner, the slippage pads having an elongated shape with a length and a width, the length being greater than the width, the slippage pads each defining a number of integrally connected side-by-side tubes each having an opening adapted to be oriented toward the wearer's head, the openings aligned longitudinally along the length of the slippage pads;
a plurality of projecting cushioning pads disposed adjacent to the slippage pads, and having a greater height than the slippage pads and exhibiting a greater deformability than the slippage pads; and
an attachment system to attach the helmet to the wearer's head.
2 . The helmet as defined in claim 1 , wherein all the slippage pads are shaped and size to be identical to each other.
3 . The helmet as defined in claim 1 , wherein lateral pairs of the slippage pads are disposed on each side of a sagittal plane of the helmet.
4 . The helmet as defined in claim 3 , wherein the lateral pairs of the slippage pads are evenly laterally spaced apart from the sagittal plane of the helmet.
5 . The helmet as defined in claim 1 , wherein a frontal pair of the slippage pads is disposed in a frontal portion of the helmet.
6 . The helmet as defined in claim 1 , further comprising at least one cushioning pad disposed on the concave inner surface of the inner liner.
7 . The helmet as defined in claim 6 , wherein the cushioning pad has apertures defined therethrough, the apertures corresponding in shape and dimensions to the slippage pads, wherein some of the slippage pads and/or of the plurality of projecting cushioning pads are disposed within the apertures of the cushioning pad.
8 . The helmet as defined in claim 1 , wherein the slippage pads have a length of 40 mm±20 mm, and a width of 13 mm±7 mm.
9 . The helmet as defined in claim 1 , wherein the projecting cushioning pads have a largest sectional dimension of 12.5 mm±2.5 mm.
10 . The helmet as defined in claim 1 , wherein the projecting cushioning pads have a height of 7.0 mm±2.0 mm.
11 . The helmet as defined in claim 10 , wherein the slippage pads have a height of 5.0 mm±2.0 mm.
13 . The helmet as defined in claim 1 , wherein a density of the slippage pads is 0.27 g/cm 3 ±0.10 g/cm 3 .
14 . The helmet as defined in claim 1 , wherein the slippage pads are made of a composite material including polyurethane and a non-Newtonian polymeric material.
15 . The helmet as defined in claim 1 , wherein the plurality of tubes is a pair of tubes, the openings of the pair of tubes each having an obround shape.
16 . The helmet according to claim 1 , wherein the projecting cushioning pads have a height that is between 5% and 40% greater than that of the slippage pads.
17 . The helmet according to claim 1 , wherein the projecting cushioning pads are cylindrical tubes.
18 . The helmet according to claim 1 , wherein the projecting cushioning pads have a hardness ranging from Duro 12-18 HC.
19 . The helmet according to claim 1 , wherein the slippage pad have a hardness ranging from Duro 25-35 HC.
20 . The helmet according to claim 1 , wherein a thickness ratio of the projecting cushioning pad relative to the slippage pads is between 1.2 and 1.7, inclusively.