US 1995543 A
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March 26, 1935. KAsER 1,995,543
TENNIS TABLE Filed Aug. 1, 1952 4 Sheets-Sheet i fvzzz enf; Evere 0. vase?" ZUL LESS m 7 731M 9 wa m 41' .Qlfis:
March 26, 1935. D, KA ER 1995,543
TENNIS TABLE March 26, 1935. KAsER 1,995,543
TENNIS TABLE Filed Aug. 1, 1952 4 Sheets-Sheet :5
Eur-3762? D. Kaser: 1
March 26, 1935" KAsER 1,995,543
.TENNIS TABLE Filed Aug. 1, 1952 4 Sheets-Sheet 4 5 25 6 '3 22472027225?" z aa $7 @676 asen Patented Mar. 26, 1935 UNITED STATES TENNIS TABLE Everett Dee Kaser, Aurora, 11]., assignor to Durabllt Steel Locker Company, Aurora, 11]., a corporation of Illinois Application August 1, 1932, Serial No. 627,229
This invention relates to tennis tables or boards as employed for the game of table tennis and the like, and particularly to tables having a sheet metal top upon which a resilient ball is bounced.
The main objects of this invention are to provide an improved metal topped table tennis board having a flexible reinforcement to back the top surface and prevent vibration thereof during play; to provide an improved table tennis board having a level playing surface that will not warp, chip,
split, nor curl, and will withstand outdoor weather; and to provide an improved molded reinforcement for such tables that will not crack or break away when the table is set up on an uneven surface and distorted by its load.
A specific embodiment of this invention is shown in the accompanying drawings, in which:
Figure 1 is a perspective view showing the tennis table as set up for play.
20 Fig. 2 is a plan view of the same partially broken away and showing the disposition of the hinges and the net supporting post sockets.
Fig. 3 is a perspective view showing a net supporting post in detail.
25 Fig. 4 is a fragmentary sectional view taken on line 44 of Fig. 2. d
Fig. 5 is a fragmentary plan view showing the arrangement of a net supporting post socket in a corner of the table.
a Fig. 6 is a fragmentary section taken on line 6--6 of Fig. 2, showing the hinge arrangement for securing the two halves of the table together, so as to be foldable one upon the otlier.
Fig. 7 is a sectional view of the same but showing the hinge separated.
Fig. 8 is a plan view of the detail shown in Fig. 7.
Fig. 9 is a fragmentary view of a table comer with the top removed to show the mounting of one of the table legs.
Fig. '10 is a view of the same showing the leg in its folded position.
Fig. 11 is a view taken on line 11-11 of Fig. 9.
Fig. 12 is a view taken on line 1212 of Fig. 9.
Fig. 13 is a perspective view showing a tennis table folded for storage or portage.
Fig. 14 is a longitudinal sectional view of the tennis table as shown in Figs. 1 and 2.
Fig. 15 is a fragmentary sectional view taken transversely through the table top and showing a modified reinforcement for the top surface.
Fig. 16 is a similar view of the same showing a second modification of the reinforcement.
Fig. 17 is a view of the same similar to Fig.
16, showing the metal reinforcement supplemented by a plastic filler.
Fig. 18 is a similar view of the same showing a plastic composition reinforcement having a metallic mesh embedded therein.
Fig. 19 is a bottom view of a tennis table having a metal reinforcement the same as shown in Fig. 15.
Fig. 20 is a detailed view showing the construction of the leg pintles.
Figure 21 is a fragmentary detail view showing a modification of the reinforcement shown in Figure 15.
In the form shown in the drawings my improved table tennis board comprises a pair of rectangular 15 sections 1 and 2 arranged edge to edge and hinged together with their adjacent edges in abutment. The table is provided with six legs 3, by which the playing surface is supported from the ground or floor upon which the table rests, and these 20 legs are disposed one in each corner of section 1, and one in each of the corners opposite the hinged side of section 2. A pair of net supporting I posts 4 are mounted on the table adjacent the hinged edges and between the posts 4 a net 5 is 25 stretched.
As shown in Figs. 4, 6 and 14, each section of the table tennis board or playing surface is formed.- of a single flat sheet of sheet metal having its margins turned at right angles to form a peripheral depending flange 6, which has its lower margin turned. inwardly at right angles and then upwardly to form a square channel 6.1 at the lower edge of the flange 6 so as to provide rigidity and strength to the table top or tennis board. 5 The table top for each section thus comprises an inverted pan and the inner surface of the pan thus formed is reinforced by two stiflening ribs 7, which are disposed at right angles to each other and extend from flange to flange to divide the pan into four quarters, and a heavy layer of flexible plastic composition 7.1,which is molded evenly in each quarter of the pan, adheres tightly to the surface thereof, where it solidifies to form a non-vibrative backing for the flat sheet metal top of said table. The ribs 7 are of the same depth as the flange 6 and are welded to the surface of the pan and to the flanges 6 so as to form a rigid structure.
In constructing the hinge 8 the upper corner 5 of the adjacent edges of the sections 1 and 2 are partly cut away as shown in Figs. 6, 7 and 8, at the places where the hinges 8 are to be located. The apertures 9 thus formed are cut deeper into the table top and into the flange at their center portions than at their lateral extremities, the depth of the cut at the lateral extremities being equivalent to one-half the diameter of the hinged pin or pintle 10. The pintle 10 is then secured across the aperture 9 of the section 1, which section is provided with four supporting legs, and the pintle is disposed so that its center line will be positioned at the intersection of the planes of the depending flange and the playing surface of the table. The pintle 10 is then welded to the edges of the table top and flange at the lateral extremities of the aperture 9, thus forming one-half of the complete hinge 8. The pivotal member 11, or swinging half of the hinge 8, is formed of a plate having one margin rolled to form a wide hook '12, adapted to hook upon and embrace the pintle 10.
The flat portion of the member 11 is inserted through the aperture 9 of the table section 2 and welded against the inner side of the respective flange 6, with the hook portion 12 positioned so that its axis of revolution is coincident with the line of intersection of the planes of the playing surface of that section and said depending flange 6. Thus when the hook 12 is hooked upon the pintle 10 and the sections 1 and 2 are disposed so that their playing surfaces are in a common plane the respective flanges 6 will be in abutment over their entire area. Also when it is desired to fold the section 2 upon the section 1, the section 2 can be swung upwardly, as
shown in dottedoutline in Fig. 6, and will fold' upon the section 1 so that the entire area of the respective playing surfaces will be in contact with each other and thus prevent their injury while the folded table is being carried or is in storage.
In the form shown in Figs. 1 and 3, the net supporting parts 4 are each formed from a flat bar bent at right angles at substantially its middle to form an angle bracket. One leg of the angle thus formed is received'and held in a socket 13 provided in the table top, and the other leg carries a flat bar 4.1 welded at the end thereof and projecting at right angles thereto in a direction opposite to the first mentioned leg. The flat bar 4.1 is wider than the bar forming the angle bracket and is positioned so that its side edges will be equally spaced from the bracket center line, forming a T-head for the bracket which, when the bracket is mounted on the table and in the socket 13, extends upwardly above the table to carry the net 5.
Each post 4 is mounted on the table with its flat surfaces parallel to the sides of the table and is positioned so that the edge of the upwardly extending T-head 4.1 nearest the adjoining edges of the table sections will extend somewhat beyond those edges and support the net in a position directly over and in line with said edges. A pair of spaced grooves are also formed on each lateral edge of the head 4.1, at the points where the net is to be tied, in order to serve as means for preventing vertical slipping of the net ties, and a pair of buttons 4.2 are provided on the outer face of each of the posts for securing the net ties.
Thus the net posts 4 are exactly alike and interchangeable so that there is no bothersome matching of any certain post to its proper side of the tableand, since the edges of the T-shaped head of each post are provided with tie grooves equally spaced from the center line thereof, the net is always supported in its proper location regardless of which post is set up on any particular side of the table.
As shown in Figs. 4 and 5 the sockets 13 which receive the net supporting posts 4 are formed by cutting rectangular apertures in the top of the table at opposite sides thereof and adjacent the hinged edge. The socket aperture 13 is preferably located at the side edges ,of the table so that the depending flange 6 will form one bearing surface for the socket end of the net supporting post 4. The opposite bearing surface is formed by providing a clip 14 shaped to snugly embrace said socket end of the post 4, and welding the clip 14 to the flange 6.
The supporting legs 3 of my improved tennis table are formed as hollow steel members. In the form shown in Figs. 9 to 14 inclusive, each leg comprises a hollow member tapering from the top to the bottom, where a fiat foot 15 is provided, and having a triangular section throughout its length. This leg structure afiords a maximum strength against vertical compression and lateral buckling forces.
The body of the leg 3 is formed from two pieces of sheet metal, one of which is bent on its longitudinal center line to form a right angle trough having equal, straight, flat sides tapering in width from the upper portion to the foot, and the other of which is a single flat tapering sheet formed to bridge and cover said trough and having its lateral margins turned up so that they will lay flatly against the sides of the trough. The two pieces are assembled by setting the tapering flat sheet upon the trough so that it will close the same, and in section appear as the hypotenuse of an isosceles triangle, and then turning the margins of the sides of the trough member inwardly through 180 degrees so as to clamp upon the turned up margins of the flat sheet, the adjoining margins being secured by spot welding or the like. 0
The hollow legs are mounted on the table sections so that the flat sides of the trough member are perpendicular to the table surface and the upper portion of the legs are squarely set in the respective section corners. the respective table corner by a V-shaped hinge which is arranged to allow the'leg to fold inwardly toward the center of the respective table section and against the under surface of the table top, as shown in Fig. 13, the depending flange 6 being preferably of sufilcient width to completely house the legs when they are in a folded position.
In the form shown the leg hinge comprises two interfitting V-shaped members. A fixed member 16, secured to the table, is formed with equal side portions disposed at right angles to each other so as to fit snugly into the corners of the table and is welded to the top of the table and the inner upturned margin of the depending flange. A swinging member fitting within the fixed member is formed of two angles 17 and 18, each having an angle of 45 degrees between their legs, arranged side by side with adjacent legs parallel and spaced apart by a block 19. The two angles 1'7 and 18 are welded to the block 19 and to the inner side of the leg trough, and are positioned so as to project above the top of the leg.
The member 16 and each of the angles 17 and 18 are provided with ears 20, which project outwardly from their lateral margins at an angle of 45 degrees from the side edges of the table. The ears 20, which are positioned above the top of the leg 3 and are paired together when the hinge Each leg is held in is assembled, extend toward the center of the respective table section and have registering apertures through which bolts 21 are inserted to provide pintlesupon which the leg 3 can be swung.
The leg hinge pintle is preferably provided with a bushing 29 mounted in the movable member, as shown in Fig. 20, in order to permit a free pivotal action without loosening the securing bolts slightly beyond the surfaces of the ears.
21. The ears 20 of the movable members are provided with enlarged apertures into which the bushing 29 is set and the bushing is made slightly thicker than the ears so that it will extend Thus when the bolt 21 is tightened down it can not grip the movable member so as to cause the bolt to turn when the movable member is operated. The head of the bolt 21 rests against a washer 30, which in turn bears against the bushing 29 so that the ear of the movable member is left free-to pivot on the bushing. The same effect can be had by providing a shouldered bolt in place of the bolt 21, the movable member pivoting upon the shoulder and the bolt being locked in place by its nut.
In order to lock the legs 3 in an extended position, a notched lug 22 is provided at the center of the fixed hinge member 16 and a spring tensioned catch 23 actuated by a spring 23.1 is mounted between the angles 1'7 and 18. The catch 23 is positioned below the block 19 and is provided with a groove 24 serving as a finger rest when it is to be operated to release the leg for folding. The catch 23 is pivoted upon a stationary bushing in the same manner as the ears of the movable hinge member.
The composition forming the backing and reinforcement 7.1 for the flat metal top of the table is designed to be heavy and stiff, but with enough flexibility or elasticity to prevent its breaking away from the bottom surface of the top or cracking in case the top should be momentarily distorted by shock or bending due to an uneven foundation or resting surface for the legs. The preferred composition is made as a plastic mixture and comprises essentially a cement or hardener such as Portland cement, plaster of Paris, or the like; an aggregate such as gravel, granulated cork, shredded-asbestos, or other granular material; and a binder of some mastic material such as emulsified asphalt.
It has been found in practice that the most satisfactory material and proportions for a composition to properly deaden the playing surface of the table to absorb the local vibrations set up therein during play, as well as providing the necessary adhesive and bending qualities, is a mixture comprising one and one-half parts by volume of cement, three parts emulsified asphalt,
' two parts sand and four parts shredded asbestos,
all mixed with sufllclent water to make the mixture plastic and workable. The plastic mass is molded directly upon the inner or bottom side of the table top, in each of the quarter sections formed by the ribs 7, and is spread evenly over vthe metal surface so as to cover the same from composition comprises a mixture in which ground cork is substituted for the shredded asbestos. This composition comprises two parts by volume of cement, four parts emulsified asphalt, .5 parts sand and 3.5 parts ground cork, and is molded In the form shown in Fig. 15, the flat sheet metal table top is reinforced against local vibration by means of corrugated sheets of metal 25 which are formed with wide, deep corrugations. Each corrugated sheet 25 is shaped to fit against and cover one of the quarter sections of the bottom surface of the table top and is arranged so that the corrugations run lengthwise of the table, as shown in Fig. 19. The sheets are secured to the table top by spot welding or the like, at many different places and the vertical sides of the corrugations. each functions as a small stiffening rib or angle which effectively prevents the playing surface from warping or tion coats the inner surfaces of both the reinforcing sheet and the table top as shown in Figure 21, and insures uniform contact between them, so that when the assembly is baked at approximately 300 F., a strong protective coating 31 is provided which prevents the collection of moisture between the sheets. However, the baking operation cannot harden the compound that lies between the substantially contacting surfaces of the sheets since the exposed edges are hardened first and seal off the inner portions, and a bond is formed between the sheets that is always perfect and resilient and provides a perfectly uniform playing surface.
In the form shown in Fig. 16, the reinforcing means comprise a series of spaced rectangular channels 26, secured to the bottom side of the table top. The sides of the channels are disposed at right angles to the metal top sheet and have their lower margins turned outwardly at right angles so as to be parallel to the top sheet. In this arrangement, the reinforcement functions much the same as the corrugated sheet shown in Fig. 15, but a saving-in the metal used is realized.
In the arrangement shown in Fig. 17, the channel reinforcement 28 of the structure shown in Fig. 16. is supplemented by the addition of the flexible plastic composition. 7.1, which is applied after the channels have been secured against the table top sheet. The flexible composition completely surrounds the channels 28 so that they are embedded therein and serve as a means for holding the composition more securely against the table top. The advantage of such an.arrangement is principally the increased rigidity and strength of the structure.
In the form shown in Fig.18. the flexible composition 7.1 is reinforced by means of a metallic mesh 28 or the like, which is embedded in the composition and serves to strengthen the same against breaking away from the table top-without be expanded metal or wire screen and is secured to the stiffening ribs and depending flanges of the table top so as to provide additional means for holding the composition against the table top.
Among the advantages of my improved tennis table is its non-vibrative all metal construction which permits a fast and hard play, that is characteristic of the present day game, without the annoying vibration of the playing surface found' in the usual tennis table. Even the bouncing of the extraordinarily light weight hollow celluloid ball is sufiicient to set up local vibrations in the usual portable table and such vibrations cans: the ball to take peculiar and uncontrollable hops and curves after the bounce. Another advantage of the solid non-vibrative surface of my tennis table is that it provides the proper bite necessary for difiicult cuts and chip shots.
My improved table is weatherproof and can be left out of doors without any fear of warping, splitting or cracking the playing surface, and, because of its reinforced construction, cannot be broken or permanently bent if set up on an un-' even surface. The improved arrangement of the legs and the hinges by which the sections are joined permits folding the table into a compact unit for carrying or storage; and my improved hinge permits thesections to be readily separated should it be desired to carry them individually, or use only the four-legged section as a card table or the like.
The term mastic as herein used is intended to define the physical characteristics of a material.
having the flexible, non-hardening and adhesive consistency of asphalt or pitch, but without reference to any specific chemical constituents.
Although but one specific embodiment of this invention is herein shown and described, it will be understood that numerous details of the construction shown maybe altered or omitted without departing from the spirit of this invention as defined by the following claims.
l. A table tennis board comprising a flat sheet metal top having a peripheral depending flange, and a flexible composite reinforcing means molded against the under side of said top and comprising a hardener and an aggregate mixed with emulsified asphalt.
2. The method of manufacturing a non-vibrative steel tennis table top, which consists in pro-'- viding a sheet steel pan having a smooth fiat bottom, mixing a hardener and an aggregate with emulsified asphalt, adding water to the mixture to make the same plastic, and molding the plastic 'detractingfrom its flexibility. The mesh 28 may mixture evenly on the inner bottom surface of said pan, said mixture adhering thereto and solidifying thereupon.
3. A table tennis board comprising a fiat inverted sheet metal pan having a flexible plastic filler molded on its inner surface to reinforce the same and prevent vibration of the top surface during play, said filler comprising a cement mixed with cork and emulsified asphalt. v4. A table tennis board comprising a fiat inverted sheet metal pan having a flexible plastic face during play, said filler comprising cement, asphalt, sand, and ground cork.
-6. A table tennis board comprisinga fiat in-.
verted sheet metal pan having a flexible plastic filler molded on its inner surface to reinforce the same and preventvibration of the top surface during play, saidfiller comprising a cement mixed with shredded asbestos and emulsified asphalt.
'7. A table tennis board comprising a fiat sheet metal top having a flexible plastic filler molded on its under side to reinforce the same and prevent vibration therein during play, said filler comprising one and one-half parts by volume of cement, two parts of sand, four parts of shredded asbestos-and three parts of emulsified asphalt.
8. A table tennis board comprising a flat sheet metal top, a reinforcing means comprising a sheet of corrugated metal secured against the under surface of said sheet metal top at points 'distributed over the horizontal area thereof, and a filler molded on its inner surface to'reinforce the same and prevent vibration of the top surbonding material filling the. voids between the I areas comprised by the contacting surfaces of said reinforcing means and sheet metal top.
9. The method of manufacturing a non-vibrative steel tennis table top, which consists in providing a sheet steel top having afiat bottom.
providing a reinforcing membercomprising a