US2934766A

US2934766A - Impact absorber

Info

Publication number: US2934766A
Application number: US657191A
Authority: US
Inventors: Cherup Nicholas
Original assignee: Individual
Current assignee: Individual
Priority date: 1957-05-06
Filing date: 1957-05-06
Publication date: 1960-05-03
Anticipated expiration: 1977-05-03

Description

N- CHERUP IMPACT ABSORBER May 3, 1960 Filed May 6, 1957 INVENTOR. 11/1010 LAS CHERUF.

BY M

I TTO RA/E) ACT ABSORBER Nicholas Cherup, Center-line, Mich.

Application May 6, 1957, Serial No. 657,191 2 Claims. or. 2-4

.Still further, it relates broadly to devices for the absorption of impact, wherein the impact is first impartedby the external force to an outer, relatively rigid shield which, in turn, by forward motion transmits the-resulting force to an inner elastic membrane in wholeor in part covering the object to be protected, causing the elastic membrane to be stretched in a reverse direction,

finally transmitting the residual force to the protected s atent object diminished in total magnitude and distributed as a relatively low pressure over a broad area of said object.

More particularly, this invention relates to equipment for the protection from impact of parts of the body, such as ribs, thighs, tibia, hands, wrists, or forearms, aid equipment comprising an outer relatively rigid shield and an inner elastic membrane covering in whole or in part the portion of the body being protected, and providing protection therefor by the reverse stretching of said elasticmembrane in response to the forwardmotion of said outer shield.

Prior art Presently, known athletic protectiveequipment is generally based on the principle of cushioning ablow by the insertion of a padding between the external force and the part of the body to be protected. In this type of device, the blow is transmitted directly, although in a somewhat rnufiied or retarded form, to the spot at which the blow was originally aimed. There is relatively little spreading of the force or impact absorption.

.20, .1930. An unyielding open frame or ring made of vulcanized rubber circumscribesthe part of the body to be protected, a padding being placed between it and the body itself. Anouter unyielding shield 'is afiixed to the ring at its opposite edges, and is spaced away from it at the top and bottom. Thus, when a force is directed at the portion of the body to be protected, it is transmitted directly to the inner ring and thence through the padding to the body substantially around the circumference of a ring surrounding the protected area. The padding serves to muffle the impact of the ring against the .body. This is necessary, since the distribution of theexternal force over the area of the ring is insufficient to permit direct bearing of the ring against the body.

This equipment thus combines the ordinary cushioning 2,934,765 Patented May 3, 1 96 0 efiect of. padding with the distribution of the external force over an annular area surrounding the portion of the body to be protected. The outer shield and inner ringare flexible enough to permit them to transmit the force without rupture, but are too rigid to provide any significant amount of impact absorption themselves.

Another type of protective equipment was described by Millet and Rogers in U.S. Patent 245,307, issued Aug. 9, 1881. The apparatus described consisted of a breast shield or armor, to beworn by workmenfor the purpose ofresting the article to be Worked upon or held against. Its object was not to absorb impact, but simply to spread a constant localized pressure over a large area of the body, soas to reduce the unit pressure. It consisted of a rigid outer shield, and an inner elastic sheet lining which was fastened around its periphery to the periphery of -the shield. The inner elastic lining rested against the chest of the wearer. shield was fastened aroundits periphery to the periphery of the inner elastic lining, and was spaced apart everywhere else. The' outer shield evidently bore against the body (through the elastic lining) around a portion of its periphery, and was separated from the body only by a slight distance around the rest of its periphery. Thus, very little, if any, forward motion of the shield could occur and therefore no significant impact could be taken up. Nevertheless, the inner lining was underltension, and the external-force was thus distributed over a large part of the body.

"Thus,'so far as I am aware, up to the present time, no one has hitherto invented an effective device for distributing a sharp external impact over the entire body or object to be protected, the only type of protection hitherto available being the conventional padding or cushioning.

Objects protected, without the need for any padding.

A third object of my invention is to provide a device for the absorption of impact by the stretching of an elastic membrane which in whole or in part covers the object to be protected. 7

A fourth object of my invention is to provide a device for the absorption of impact, wherein the impact is first imparted by the external force to anouter, relatively rigid shield which, in turn, by forward motion, transmits the resulting force to an inner elastic membrane in Whole or in part covering the object to be protected, causing the elastic membrane to be stretched in a reverse direction, finally transmitting the residual force to the protected object diminished in total magnitude and distributed as a relatively low pressure over a broad area of said object.

' A fifth objective of my invention is to provideequipment for the protection from impact of parts of the body, said equipment comprising an outer, relatively rigid, shield and an inner elastic membrane covering in whole or in part the portion of the body being protected, and providing protection therefor by the reverse stretching of said elastic membrane in response to the forward motion of said outer shield.

Advantages An advantage of my invention is that it provides effective absorption of impact. A second advantage of my invention is that it provides The outer rigid effective absorption of impact without the need for any padding.

A third advantage of my invention is that it provides effective absorption of impact, coupled with distribution of the residual force over abroad area of the object being protected. t

A fourth advantage of my invention is that it provides effective absorption of impact anddistribution' of the res idual force over a broad area of the object being protected by means of an elastic membrane which is protected against direct impact by the external force.

A fifth advantage of my invention is that it provides for impact absorption by first providing forward momentum to an outer rigid shield, second providing reverse stretching of aninnerelastic'membrane, and third distribution of the residual force over a broad area of the object being protected. l

A sixth advantage of my invention is that it is much lighter than padding-type protective devices, as well as being much more effective. v j

Other objects and advantages of my invention will more fully appear from the description taken in connection with the accompanying drawings, wherein are disclosed preferred embodiments of my invention.

Drawings Fig. 1 is a schematic view of a preferred embodiment of my invention, in cross-section, showing a force about to be applied. I a

Fig. 2 is a second schematic view of the same embodiment of my invention, in cross-section, showing the result of the application of said force.

Fig. 3 is a schematic view, in cross-section, of, a second embodiment of my invention. Y v

Fig. 4 is a plan view of a third embodiment of my invention, namely an athletic rib protector.

Fig. 5 is a cross sectional view, taken along the line 5-5 of Fig. 4.

Description which case these diagrams will representfhorizontal cross:

sections.

Circumscribing the object 10 is a relatively rigid outer cylindrical shield 11, which may for example,lconsist of a plastic material. In contact with a large'portion of the surface of the object 10 is an inner elastic-cylindrical membrane 12, which is fixed to the shield. 11 along two spaced apart vertical lines 13, 14 (appearing in crosssection as points). The shield 11 is at all other points spaced apart fromthe elastic membrane 12, the distance of separation at the rear extremities being designated as X 7 In Fig. l the front portion 15 of the shield 11 is in contact with the front surface of the object 10. The free length of the elastic membrane 12 is less than the portion of the perimeter of object 10 between

points

13 and 14 via 16. Thus, the elastic membrane 12 is under some tension in Fig. 1, since it has been stretched around the object 10.

Now, assume that an external force F issuddenly applied at some point along the rear portion of the shield 11, as shown in Fig. l. The force F is first transmitted to the shield 11 which therefore begins to move in accel- 'erated motion. However, the forward motion of the shield 11 is retarded by the elastic membrane 12. Since the object 10 is as yet stationary, being for example retarded by friction along the ground, the 'rear portion of the elastic membrane 12 will also be stationary. But,

attached to the shield 11 at

points

13 and 14, the elastic membrane 12 will stretch. This stretching causes inceased tension in the elastic membrane, thereby retarding further forward motion of the shield 11.

The situation immediately after impact is shown in Fig. 2, the elastic membrane 12 being stretched. The distance of separation at the rear extremities is now decreased to X while there is now a distance of separation X between the front 15 of the shield 11 and the front of the object 10, the sum of X and X being equal to X There is now a more or less uniform pressure being exerted on the rear of the object 10 by the elastic membrane 12. The total force on the object 10 has been diminished firstly by the momentum given to the shield 11, and secondly by the energy absorbed by the stretching of the elastic membrane 19. In addition, the residual force is now distributed over a large area of the surface of the object 10, so that the unit pressure is very much lower against any portion of this object 10 than it was originally against the shield 11 (and hence very much lower than it would otherwise have been against the object 10).

The situation shown in Fig. 2 is of course temporary, since the increased tension in the stretched elastic membrane 12 creates a restoring force tending to move the shield 11 back to its original position, and also having some tendency to force the object 10 forward In either event, the ultimate result will be to reduce the distance X; to zero, and the conditions of Fig. 1 will thus be reestablished.

Thus, the principle of operation of my invention may be stated briefly as follows: An external impact is transmitted to a rigid outer shield which accordingly moves forward. The force is then distributed overthe surface of an inner elastic membrane which covers at least a portion of the object to be protected, and which is affixed to the shield in part and elsewhere is spaced apart from the shield. There is thus a reverse stretching of the elastic membrane, which ultimately distributes the residual force over a broad area of the object.

As shown in Fig. 3, the shape of the shield 11 and elastic membrane 12' may be varied as desired, not being in any way critical. In Fig. 3, the shield 11' and elastic membrane 12 are shown as attached together at lines 13 and 14' (shown again as points, in cross-section). In this case, however, the shield 11' does not fully circumscribe the object 10, but terminates at points 13' and 14'.

In Figs. 1 and 2, the elastic membrane 12 is attached at its extremities to the shield 11 along

lines

13 and 14. If desired, the elastic membrane may completely circumscribe the object 10, being substantially a girdle therefor, in which case it may if desired be attached to the shield 11 all along the surface between

lines

13 and 14. No

' separate drawing is shown in this case, since the appearsince the front portions of the'elastic membrane 12 are (5 ance is the same as that shown in Figs. 1 and 2.

Furthermore, the distance in Figs. 1 and.2 between

lines

13 and 14 may be any suitable distance, as desired. It preferably is somewhat less than the diameter or greatestbreadth of the object 10. If desired, the distance between

lines

13 and 14 can be made to approach zero, but this is not preferred.

Figs. 4 and 5 show an embodiment of the invention which I have found experimentally to constitutean extremely effective, lightweight athletic protector, e.g. a protector from impact for ribs, thighs, tibia, hands, wrists, forearms, etc. An outer, relatively rigid, shield 11", preferably of plastic extends part way around the part of the body to be protected (e.g. about the waist, in the case of a rib protector). An inner elastic membrane 12" circumscribes the part of the body to be protected (not shown), and is fastened to the two ends of the shield 11" by any suitable fastening means 18, such as screws. .Closing the gapbetween the two ends of the shield 12" is-a conventional athletic padding 17, which is alsofastened to the shield 12 by the aforesaid fastening means 18. This padding serves in the conventional way, providing additional protection in the event of an impact received in a less sensitive area of the body. Since said padding 17 extends longitudinally the same length as said outer shield 11" and inner elastic membrane 12 (as seen in Fig. 5), it also avoids any possibility of a concentrated force acting rearwardly on the forward portion of the body by reaction to the applied impact, as would be the case if straps were used instead of said padding 17.

Any suitable means (not shown) of supporting the device on the body of a person (such as shoulder straps) may be affixed thereto. I have found devices of this type to be very much lighter in weight than conventional athletic protectors, and very much more effective. For example, a football player with a broken rib has been enabled by the use of this device to play a full sixty minute game.

Regardless of the exact shape and construction I may use in these devices, certain features are nevertheless critical in any case. Since my invention is based on forward motion of an outer shield, it is vital that this not be directly impeded by the body or object to be protected. Thus, it is necessary that the maximum lateral opening in the shield exceed the greatest lateral breadth of the object, so that the shield can move forward without its ends or edges binding against the object. Forward motion of the shield with respect to the object thus remains unimpeded unless and until the rear portion of the shield reaches the rear of the object. This is in distinct contrast .with the prior art described in the patent by Millet and Rogers cited above. Their breast armor could undergo substantially no forward movement under a force, since it bore against the body, and therefore was not capable of absorbing an impact.

It is also necessary, in my invention, that the shield envelop the object, in the sense that it pass around the region of the greatest lateral breadth of said object to a region substantially forward thereof. This is necessary in order that the forward motion of the shield cause substantially a reverse stretch of the elastic membrane which is attached thereto. It is not necessary that either the shield or the elastic membrane completely circumscribe the object.

It is also necessary, in my invention, that the forward edges of the elastic membrane be fastened to the shield, but that the rest of the elastic membrane be spaced apart therefrom. In the figures, I have shown the forward vertical edges of the elastic membrane fastened to the shield. It is to be understood that I may in addition to, or in the alternative, fasten the forward horizontaledges of the elastic membrane to the shield.

It will thus be seen that I have provided a new and novel impact absorber, which absorbs impact by the inertia of an outer shield, coupled with the reverse stretchof an inner elastic membrane.

It is an improvement over conventional impact absorbers of the padding type, in that in my invention the impact is diminished by inertia and by elastic stretching, and the residual force is distributed over a broad area of the object to be protected.

It is an improvement over the prior art described by Millet and Rogers, and cited above, in that by making substantial forward motion of the shield possible, I can absorb not merely a static force, but a sharp impact.

It is an improvement over the prior art described by Volz, and cited above, in that it eliminates the need for padding, distributes the impact over a broad area of the object to be protected, and absorbs the impact more effectively by means of inertia and stretching of an elastic membrane.

Thus, devices known which (1) distribute a force over broad area Without being able to absorb impact (e.g. Millet and Rogers), (2) absorb a small amount of impact by cushioning, without distributing the force over a broad area (e.g. conventional athletic protectors utilizing padding), or (3) distribute an impact over a relatively small area and then absorb a small portion thereof by means of padding (e.g. Volz). I am unaware of any device which does what my invention does, namely effectively absorbs impact by inertia and elastic stretching, distributes the residual force over a broad area, and at the same time greatly reduces the weight of the equipment.

While I have described preferred embodiments of my invention, various modifications in the details of construction may be made without departing from the spirit of my invention, the principal novel features of which are set forth below.

I claim:

1. An impact absorber, comprising: a cylindrical outer shield, having a closed perimeter exceeding that of an object to be protected, a breadth exceeding that of the object to be protected, and a longitudinal length at least equal to the length of the portion of the object to be protected; and a curvate inner elastic member of suitable strength and elasticity, having a longitudinal length substantially the same as that of said outer shield and a breadth substantially smaller than that of said outer shield, being of such breadth as to closely embrace the object to be protected, and being completely circumscribed longitudinally by said outer shield; said inner elastic member being suitably fastened to said outer shield along a pair of spaced-apart longitudinal lines, substantially along the full longitudinal length of said inner elastic member, and being spaced apart therefrom elsewhere; said outer shield in the portion spaced from the inner elastic member being rigid and self-sustaining, and being adapted to receive and distribute the force of a blow over the surface of the object in contact with said inner elastic member; said inner elastic member and said outer shield being adapted to cooperate in response to an external impact upon the surface of said outer shield at any position remote from the aforesaid lines of fastening of said inner member and said outer shield, to permit substantial motion of said outer shield towards said inner member, together with substantial reverse elastic stretching of said inner elastic member, to an extent which is insufficient to cause bearing contact of said inner elastic member and said outer shield at points other than in the region of the lines of fastening of said members to each other during normal use, thereby absorbing elastically and reversibly a substantial portion of said impact and distributing the residual force at reduced intensity over the surface of the object in contact with said inner elastic member.

2. The impact absorber set forth in claim 1, wherein the portion of said outer shield between said lines of fastening, opposite to the spaced-apart portion, includes 9. padding material.

References Cited in the file of this patent UNITED STATES PATENTS 245,307 Millet et al. Aug. 9, 1881 696,764 Shibe Apr. 1-, 1902 1,646,272 Bates Oct. 18, 1927 1,772,922 Volz Aug. 12, 1930 1,805,734 Jones May19, 1931 2,250,275 Riddell July 22, 1941 2,758,305 Gross Aug. 14, 1956