This invention relates generally to a shoe insert and more specifically to a shoe insert for the heel of the shoe which acts as a heel shock absorber.
Numerous shoe inserts have been proposed and are on the market today. These inserts range from a general type of soft cushioning material as well as to inserts which seek to establish air circulation within the shoe, and to inserts which are designed to reduce foot odour. In all cases of which I am aware, these inserts are designed for purposes such as the above and are not designed so as to act as shock absorbers relative to the effect of foot impact on the ground during walking, jogging or running. It is well known that, in the normal walking gait, the heel of a shoe worn by a walker strikes the ground first and causes an impact on the heel of the person wearing the shoe. This can be uncomfortable and in some cases highly undesirable if the person is suffering from any foot, ankle or leg ailments.
Accordingly, this invention seeks to provide a shoe insert which acts as a heel shock absorber.
The features which define a heel shock absorber in accordance with this invention are set out in the following claim 1.
Desirably the heel shock absorber easily fits as a shoe insert within the heel end of the users shoe and geometrically conforms to the heel end of the shoe so as to provide a substantially snug fit within the shoe.
Preferably the shoe insert which acts as a heel shock absorber has an upper surface with its surrounding wall which substantially confirms to the shape of the heel of the person wearing the shoe.
Suitably the material from which the shock absorber insert is made is flexible while providing substantial protection against wear.
The invention will now be further described, by way of example with reference to the accompanying drawing, in which:-
- Figure 1- is a perspective view of one embodiment of heel shock absorber according to the present invention;
- Figure 2 is a plan from above of the shock absorber of Figure 1;
- Figure 3 is a sectional view taken along the lines 3-3 of Figure 2; and
- Figure 4 is a sectional view taken along the lines 4-4 of Figure 2.
There is shown in the drawing a heel shock absorber 11 which is adapted for insertion into a shoe shown partially in chain lines in Figure 4. The shock absorber includes a base 13 having an upper face 15 and a lower face 17. Additionally, there is provided a shallow heel recess 19 in the upper face 15.
A wall 21 extends upwardly from the base 13 to a predetermined height of an upper edge 23 at its rear end. The upper edges 24 of the sides of the wall 21 taper downwardly from the edge 23 at the rear end of the absorber 11 to a front edge 25 of the base 13. The thickness of the wall 21 diminishes from the vicinity of the surface 15 to the respective edges 23, 24.
The shock absorber 11 is an insert made'of flexible material of a consistency such that it will have good wearing characteristics and will also be firm enough to maintain its configuration in use. The material is preferably a plastics material having a specific gravity between 0.8 and 1.2 and a durometer hardness of between 36 and 50. One such material which is available in the USA is known by the trademark Kraton 5152 owned by Shell Chemical. This particular material has a specific gravity of 1.00 and a durometer hardness of 46. In the preferred embodiment illustrated, the entire shock absorber 11 is moulded in one piece so as to be integral throughout.
In order to use the material described above in a configuration which will provide the desired shock absorbing characteristics, a plurality of substantially open parallel channels 27 extend laterally across the width of the base 13 and are spaced apart along its longitudinal axis, being separated by partitions 30. It is preferred that the channels are designed such that the upper portion of each partition 30 is wider than its central portion. This configuration allows for flexibility of the partitions 30 between the channels so as to give the necessary shock absorbing effect. One reason that it is preferred that the upper part of each partition is wider than its central part is that this shaping of the channels at least reduces and at best prevents any sensation on the heel of the existence of the partitions.
As is more clearly shown in Figure 4, the thickness between the faces 15 and 17 remains substantially constant from a portion adjacent the rear heel area to a portion well forward thereof until, at the forward end thereof, the width of the base diminishes as the forward portion tapers (at an angle cf as indicated) to the front edge 25. This downwardly sloping region is indicated at 35 in Figure 4 and it will be noted that the frontmost channel (27') also narrows slightly to confirm to the sloping surface 35.
As is clear from the drawing, the wall 21 maintains the predetermined height of the edge 23 around the rear part of the heel and then tapers downwardly along the edges 24 to the point at which the base thickness begins to diminish. The angle of this taper is designated a in Figure 4.
Referring particularly to Figure 3, it can be seen that the shock absorber is designed so as to include an arcuate area 31 between the base 13 and the wall 21 so as to more confortably conform to the sides and rear of the heel of the person who is using the shock absorber. This configuration is generally carried forward for the entire length of the wall 21 although the radius of curvature of the arcuate area reduces the closer it is to the forward end of the absorber 11.
In order to ensure that the absorber insert 11 remains in place in the heel end region of the shoe, gripping means 33 are provided which depend from the lower face 17 of the base 13. In the particular configuration illustrated, the gripping means takes the form of a plurality of pegs. Since the pegs are of the same material as the rest of the shock absorber, they provide flexibility while still providing the desired gripping feature.
While not limiting the invention in any way, a satisfactory construction for a shock absorber heel insert includes the following dimensions.
It is to be understood that shock absorbers according to the present invention will normally be made in varying sizes (such as small, medium and large) so as to fit properly in the different sizes of shoes available. The present invention has been proven to provide extremely noticeable comfort and relief from the shock normally accompanying the impact of the heel during a walking motion. By relieving this shock, the entire foot, ankle and the leg are benefited.
The above description and drawing are illustrative only and are not intended to limit the invention, the scope of which is to be determnined by the following claims.