US 2771618 A
Description (OCR text may contain errors)
H. E. CRUM SWIMMING APPLIANCE Nov. 27, 1956- 5 S heetS-SiiQet 1 Filed Jan. 11, 1954 HA nvgr E. cRuM, mmvnm.
A T TORNEK MW. 27, 1956 M. 2,771,618
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A TTORNEK United States Patent SWIMMING APPLIANCE Harvey E. Crum, Santa Monica, Calif.
Application January 11, 1954, Serial No. 403,310
1 Claim. (Cl. 9-21) This invention relates to a swimming appliance particularly adapted to be worn on the swimmers forearm to assist in the propulsion of the body through the water.
Many devices of this general character have been known; however, none prior to my invention has been satisfactory, especially with respect to facility of operation in opening easily to provide a fin for the forward stroke and closing easily to avoid resistance of the fin on the return stroke during swimming.
In accordance with my invention, however, I provide a device which can readily and satisfactorily be applied to the forearm and which will open readily on the swimming stroke to provide a fin to assist propulsion and will readily fold to avoid resistance on the return stroke. The device of my invention is moreover relatively simple and direct and effective in its operation.
In general, in accordance with the preferred embodiment of my invention it comprises an elongated body structure adapted to be fitted along the lower portion -of the forearm by means of a cuff extending from said body structure and adapted to be laced about and at the top of the extended forearm (with the back of the hand upward as in a swimming stroke). Extending from each side of the body structure are means movably mounted upon the body structure to support a fin or webbing and adapted to hold the webbing outward in extended position during a swimming stroke and to fold or retract the webbing on the return stroke.
In order to illustrate my invention there is shown in the drawings a specific embodiment thereof which will be described taken in conjunction with the accompanying drawings in which: a
Fig. 1 is a diagrammatic functional view of the use of my improved swimming device showing one attached to each arm, the right arm illustrating the opened position of the fins during the backward propelling stroke, the left arm illustrating the folded or contracted position of the fins during the forward reach.
Fig. 2 is a sideview of my swimming device showing it, in its folded position, attached to the arm.
Fig. 3 is a plan view of the device showing it, in its expanded position, attached to the arm.
Fig. 4 is a side view of the device showing it, in its expanded position, attached to the arm.
Fig. 5 is a plan view of the device showing it in its folded position.
Fig. 6 is a section view on the line 66, Fig. 3.
Fig. 7 is a detail plan view showing how the ribs of the fin are attached to the underside of the body structure.
Fig. 8 is a detail view of a portion of Fig. 6 showing, in detail, how the ribs or" the fin are movably mounted to the body structure.
in accordance with the specific embodiment of my invention here illustrated an elongated central body structure 1, which is light, substantially thin and flat and as shown most clearly in Figures 4, 6, 7 and 8 is adapted to be affixed to the forearm 2 of the swimmer by means of a cufi 3 of flexible material, preferably elastic cloth, attached to the body structure and adapted to be laced about and at the top of the forearm by laces 4. Extending outward and somewhat downwardly from each side of the elongated body structure 1 are ribs 5, 6, 7 and 8 extending to the right and ribs 5', 6', 7' and 8' extending to the left, as shown in Fig. 3. Extending between each rib and between the two sets of ribs 5, 6, 7 and 8 and 5, 6, 7' and 8 and under the body structure 1 is a webbing 9, preferably of flexible material such as sheet rubber.
As will be explained in more detail below, ribs 5, 6, 7 and 8 and 5, 6', 7 and 8 are movably mounted to the elongated central body structure 1 to move from the extended position shown in Fig. 3 to the folded position shown in Fig. 5. The webbing 9 is afiixed to ribs 5 and 5 by overlapping end flaps 10 and 10 of the webbing which extend around and on top of ribs 5 and 5' and are afiixed to the overlapping portion of the webbing by a suitable adhesive. Webbing 9, as viewed in Fig. 3, extends underneath ribs 6, 7, 6 and 7', and is fastened to ribs 8 and 8 by overlapping end flaps 11 and 11'. The webbing 9 is afiixed to ribs 6, 7, 6' and 7' at the ends by an overlapping portion of the webbing 12 and 12' which is affixed over the ends of the ribs by a suitable adhesive. The webbing is movably supported to ribs 6, 7, 6' and 7' by small strips 13, 14, 13' and 14 extending over the respective ribs and aflixed to the webbing by means of adhesive. Strips 13, 14, 13' .and 14' are preferably so affixed to the respective ribs 6, 7, 6 and 7' that with the expanding and folding of the webbing the webbing may move slightly with respect to the ribs; that is, the web and the strip may move slightly along the rib. This allows flexibility of the web in moving from the expanded to the folded position and return. The webbing is preferably made of flexible material such as rubber to permit stretching between such points as A and B on Fig. 3 as the ribs move from the fully expanded position to the folded position.
The webbing 9 is so aflixed and of such shape that in the fully expanded position shown in Fig. 3 with the ribs fully extended the webbing is fairly taut especially between the ribs to provide a fin for the swimming stroke but slightly loose in the region under the arm and elongated body structure. Under the arm and body structure the webbing is free and not supported to the body structure or the ribs except preferably at the front end of the body structure as shown at 15 in Fig. 7. Here the webbing is attached to the front end of the body structure by a piece 15 to avoid the entry of most of the water between the web and the elongated body member 1 on the part of the return stroke. However, the region 15 is cut away to allow free movement of ribs 5 and 5' back and forth. Also, at this point, the webbing is loose to permit the free movement of ribs 5 and 5' from folding to extended position.
As shown most clearly in Figures 6, 7 and 8, each of the ribs extend outwardly and downwardly at an angle from the horizontal as shown generally in Fig. 6. With this arrangement the ribs hold the web outward and substantially in somewhat of a cup to act as a fin which will not double back under the force of the water during a swimming stroke. Each rib is movably mounted to the elongated central body structure 1 for limited relative movement with respect thereto as shown in detail in Figures 7 and 8. Each rib has a spherical end portion 16 which fits into a corresponding spherical indentation 17 formed within the body structure 1 and is rotatably held therein by means of a metal cap member 18 having a cup member 19 of spherical configuration on the inside to conform to the spherical end portion 16 of the rib. This forms what may be termed a cup and ball ge. Metal cap 18 is affixed to 'the under side of the elongated central body structure 1 by rivets 20 through holes 21 in a flat portion 22 of the metal cap member -18. Spherical end -16 is thus rotatable between cup 19 and the spherical indentation 17.
The 'rib'is restricted in its downward movement by the end 23 of-cup member 19 but may be moved back and forth substantially in the plane of the set of four ribs on any one side of the body portion; backward until the rib extending from the spherical end 16 contacts the back part 24 of the metal cap 18 in its backward motion and forward until the rib contacts the front 25 of the-metal cap in its forward motion. To restrict the movement of the ribs upwardly, the two sides of body structure I extend downwardly as shown at 26 and 27 in Figures 6 and 8. Thus, it will be seen that each rib ismovably mounted to the body structure 1 to permit movement of the rib from the extended portion shown in Figure 3 to the folded portion shown in Fig. while .each rib is substantially restrained from movement up or down out of a plane substantially corresponding with the four ribs of any set except for a very slight motion up or down to allow a little flexibility.
Each downwardly extending side 26 and 27 of the body member 1 is formed to have an inclined edge for each rib along which the rib slides when water presses against .the web and the web presses against the ribs. Thus, each rib as it moves backward and forward may slide along and is restricted in its upward movement by an inclined edge 28 with one such edge for each rib. The forward movement of each rib, however, is restricted by stops in the form of notches 29, one for each rib. Thus, as the ribs move back and forth from the extended position to the folded position they contact stops 29 in the fully extended position and in the fully folded position as shown in Fig. 2 the ribs move underneath and slightly away from the down turned edges 26. In the downward swimming stroke, as pressure of the water against the web is applied upwardly against the ribs, they are moved forward, because they tend to slide on the inclined edges '28 into the position against the notches or stops 29. This tends to move the ribs into the fully extended position. On the return stroke the ribs all move'backward and fold the web as shown in Figures 2 and 5, because on the return stroke the water pressure is applied substantially in the direction shown by arrow C in Fig. 2.
My device is shown in use on both arms in Fig. 1 where on the left forearm 30 a device'in accordance with my invention is shown generally retracted as the left arm is being moved forward just prior to a downward stroke. The right arm 31 is shown near the end of a swimming stroke with the device in accordance with my invention fully extended prior to the return stroke.
A single lace 4 may be fastened at 35 so that the lacing may be effected with the free arm. Another lace 36 may be attached to body member 1 as at 37, which lace is adapted to be wrapped around the folded device -but not in use.
In operation my device may be worn on the forearm of the swimmer. On the swimming stroke under the pressure of the water against the webbing 9 the fin will open to the fully extended position. This is especially so because the pressure of the water against the web pushes the supporting ribs against the inclined edges 28 so that in effect the ribs are forced down these inclined edges to a position against the stops 29. This provides a strong fin of substantial area for propulsion. On the return stroke the arm moves through the Water as in Fig. 2 so the water pushes on the device in the direction of the arrow C in,-Fig. 2 to cause the web to fold and avoid the resistance of the fin on the return stroke. Each rib is so arranged and movably mounted that the webbing will readily fold with the position shown in Fig. 5,. with each of the ribs substantially above one another. However, as soon as the arm starts in a propulsion stroke, the fin opens immediately to provide a swimming fin.
Having thus described my invention, I claim:
A swimming appliance comprising an elongated substantially fiat member adapted to be affixed lengthwise to the under portion of the forearm of a swimmer, an elongated flexible cuff affixed lengthwise to the top of said member and adapted to be laced on to said forearm, ribs movably mounted to the underside of and extending downwardly at a small angle from the horizontal from each side of said elongated member and adapted to support a web affixed to the outer edges of said ribs and adapted to move substantially in a plane of a set of said ribs on each side of said elongated member forwardly to an expanded position and backwardly to a folded position, a web forming a fin extending from the outer edges of said ribs underneath said elongated means, said web adapted to flex and ribs adapted to move and together expand and form a fin under the pressure of water thereagainst in a downward swimming stroke and to retract and fold to avoid resistance on a return swimming stroke, said elongated substantially flat member having downwardly extending edges on each side thereof extending toward said ribs with each of said downwardly extending edges having an inclined edge corresponding to each rib so that said rib can ride down the incline thereof when said rib is placed thereagainst under the pressure of a downward swimming stroke.
References Cited in the file of this patent UNITED STATES PATENTS 1,202,083 Mee Oct. 24, 1916 1,430,600 Snapp Oct. 3, 1922 1,779,590 Eilers Oct. 28, 1930 1,908,184 Richmond May 9, 1933 FOREIGN PATENTS 180,713 Switzerland Jan. 16, 1936 333,499 Great Britain Aug. 14, 1930