Safety helmet

Claim 2

A safety helmet comprising: a first semi-spherical helmet section adapted to cover the top portion of the wearer''s head; a second semi-spherical helmet section adapted to cover the lower back portion of the wearer''s head, said first section being nested within said second section with the lower edge of said second section forming the lower rear edge of said helmet and the upper edge of said second section being engaged on the lower portion of said first section, and pivot means for pivotally connecting said second section to said first section about an axis coinciding with a central axis of the first and second sections whereby the second section is slidable over a semi-spherical surface of said first section; means for biasing said second section downwardly to a position covering the lower rear portion of the wearer''s head, said second section, in response to a high impact accident causing whip-lash of the wearer''s head, pivoting upwardly in sliding engagement with said first section to minimize injury to the neck of the wearer; and stop means interacting between said first and second sections to limit pivotal motion between said sections such that the lower edge of said second section cannot reach the position of the lower edge of said first section, said lower edge of the second section being in the form of an impact-absorbing flange to prevent injury to the wearer.

Claim 3

A safety helmet as recited in claim 1, wherein said second section is pivoted to said first section about a pivot axis which is located as near as possible to the cervical skull axis of the wearer.

Claim 4

A safety helmet as recited in claim 1, wherein first stop means limits downward movement of said second section relative to said first section and second stop means limits upward movement of said second section relative to said first section.

Claim 5

A safety helmet as recited in claim 3, wherein said second stop means is so positioned that said lower edge of the second section is stopped relative to said first section at a predetermined position which corresponds to flexing of the wearer''s neck to less than 50*.

Claim 6

A safety helmet as recited in claim 1, wherein said broad flange is covered with substantial padding to cushion impact with the wearer''s neck.

Claim 7

A safety helmet as recited in claim 5, wherein said lower edge is so positioned that it will engage the wearer''s neck at a point below the upper fragile cervical area.

Claim 8

A safety helmet as recited in claim 6, wherein said point of engagement of said lower edge is below the third cervical vertebra.

Claim 9

A safety helmet as recited in claim 6, wherein said second section is pivoted to said first section about a pivot axis which is located as near as possible to the cervical skull axis of the wearer.

Claim 10

A safety helmet as recited in claim 6, wherein first stop means limits downward movement of said second section relative to said first section and second stop means limits upward movement of said second section relative to said first section.

Claim 11

A safety helmet as recited in claim 9, wherein said section stop means is so positioned that said lower edge of the second section is stopped relative to said first section at a predetermined position which corresponds to flexing of the wearer''s neck to less than 50*.

Claim 12

A safety helmet comprising, in combination: a pair of helmet sections disposed in nested relation so as to provide inner and outer helmet sections, said inner section having a top portion and a rear portion in which said rear portion presents an outer part-spherical surface of generally sectorial form, said outer helmet section being of part-spherical, sectorial form; means connecting the inner and outer sections about a pivot axis coinciding with the central axis of said sectorial surface of the inner section and of said sectorial surface of the outer section for allowing said outer section to swing about said pivot axis relative to said inner section; said rear portion of the inner section having a free marginal edge portion overlapped by said outer section, first stop means extending along said free marginal edge portion and second stop means extending along a path parallel to but spaced from said first stop means; said outer section having a lower edge portion presenting an impact-absorbing flange and an upper marginal edge portion, and abutment means along said upper marginal edge portion for engaging said first and second stop means to establish respectively a normal and an abnormal position of said outer section with respect to said inner section, said outer section being of a width greater than the spacing between said first and second stop means whereby said impact-absorbing flange is disposed outwardly beyond said free marginal edge portion of the inner section when said abutment means is in engagement with said second stop means; and means normally maintaining said abutment means against said first stop means for resisting movement of said outer section to said abnormal position thereof.

Claim 13

A safety helmet comprising, in combination: a pair of helmet sections disposed in nested relation so as to provide inner and outer helmet sections, said inner section having a top portion and a rear portion in which said rear portion presents an outer part-spherical surface of generally sectorial form, said outer helmet section being of part-spherical, sectorial form; means connecting the inner and outer sections about a pivot axis coinciding with the central axis of said sectorial surface of the inner section and of said sectorial surface of the outer section for allowing said outer section to swing about said pivot axis relative to said inner section; said rear portion of the inner section having a free marginal edge portion overlapped by said outer section, first stop means extending along said free marginal edge portion and second stop means extending along a path parallel to but spaced from said first stop means; said outer section having a lower edge portion presenting an impact-absorbing flange and an upper marginal edge portion, and abutment means along said upper marginal edge portion for engaging said first and second stop means to establish respectively a normal and an abnormal position of said outer section with respect to said inner section, said outer section being of a width greater than the spacing between said first and second stop means whereby said impact-absorbing flange is disposed outwardly beyond said free marginal edge portion of the inner section when said abutment means is in engagement with said second stop means; and means normally maintaining said abutment means against said first stop means for resisting movement of said outer section to said abnormal position thereof.

Claim 14

A safety helmet as defined in claim 11 wherein said means normally maintaining said abutment means against said first stop means comprises a spring biasing said abutment means against said first stop means whereby said outer section moves against increasing spring reacation force as said abutment means approaches said second stop means.

Claim 15

A safety helmet as defined in claim 12 wherein said first stop means is in the form of spaced projections and said outer section includes a padding liner having grooves receiving said projections.