Patio tabletop glass with broken protection

[0001] This is a Divisional Application of a Non-Provisional Application, application number 09/650,253, filed Aug. 29, 2000, which is a Continuation-In-Part Application of a non-provisional application, application number 09/206,922, filed Dec. 07, 1998.

[0002] The present invention relates to an outdoor tabletop glass, and more particularly to a manufacturing process of patio tabletop glass with broken protection to prevent the broken: glass particles from hurting the users when the patio tabletop glass is accidentally broken.

[0003] Patio table is one of the most popular outdoor furniture, which normally is placed in the patio or the back yard for the users to rest and serve barbecue. For easy clean, decorating and other reasons, most patio table has a glass made tabletop. The tabletop glass, which is simply placed on top of a table frame, generally has a central hole adapted to hold an umbrella in position for sunshine shading.

[0004] The biggest shortcoming of the patio tabletop glass is its fragile nature especially when using outdoors. It is reported that even though most of the patio tabletop glasses are made of tempered glass, the patio tabletop glass may be broken when its surface is impacted with a sharp object; when it hardly falls on ground; or when a small stone hits on it in high speed. The central hole of the patio tabletop glass is the most weakened area because of the high concentrate stress occurred around the hole. Besides, when wild wind blows on the opened umbrella, it may cause the whole patio table to fall down and break the tabletop glass.

[0005] No matter the patio tabletop glass is broken by any aforesaid reason or other unexpected reasons, the glass is broken into particles and/or pieces with sharp edges that may cause serious body injury to the users, especially to the minors. However, no glass is unbreakable. Thus, the applicant of the present invention seeks a different way to resolve the above problem, i.e. to prevent the broken glass pieces and particles from breaking apart.

[0006] It is thus a first object of the present invention to provide a patio tabletop glass with broken protection, wherein even when the patio tabletop glass is broken into pieces and p articles, the broken glass pieces and particles will not breaking apart and remain attaching to a protection layer.

[0007] A further object of the present invention is to provide a patio tabletop glass which is fast and inexpensive adapted for mass production.

[0008] Another object of the present invention is to provide a patio tabletop glass with broken protection, which provides a central hole on a protection layer after it is firmly adhered on a tempered glass layer without causing an elongated bubble popping up between the tempered glass layer and the protective layer and extending from the edge of the central hole to the peripheral edge of the tabletop glass.

[0009] Another object of the present invention is to provide a patio tabletop glass with broken protection, wherein the round edge of the center hole of the protection layer is made to form a protective edge extended around the central hole of the tempered glass layer which is the most weakened area because of the high concentrate stress occurred around the central hole.

[0010] Accordingly, in order to accomplish the above objects, the present invention provides a patio tabletop glass with broken protection, which comprises a tempered glass layer having a predetermined shape and size, a protection layer made of polyvinyl chloride or polyester sheet having a thickness of 0.3 to 0.8 mm and a shape and size adapted to cover a top surface of the tempered glass layer, and an adhesive layer which has a preferred thickness between 0.1 to 0.2 mm and is made of acrylic adhesive and the like being evenly applied between the top surface of the tempered glass layer and a bottom surface of the protection layer so as to integrally adhere the protection layer with the tempered glass layer to form an one piece body, wherein the patio tabletop glass is manufactured by the steps of:

[0011] (a) fully cleaning at least the top surface of the tempered glass layer which has a central hole thereon with neutral water having a pH of 7 so as to remove any possible oil thereon;

[0012] (b) drying the cleaned tempered glass layer;

[0013] (c) heating the entire tempered glass layer to a temperature between 45° C. to 65° C.;

[0014] (d) evenly applying a kind of acrylic adhesive on the top surface of the tempered glass layer which temperature is maintained between 45° C. to 65° C. to form the adhesive layer;

[0015] (e) attaching the protection layer having a thickness of 0.3 to 0.8 mm and a width size larger than the tempered glass layer on top of the adhesive layer of the tempered glass layer by pressing the protection layer against the top surface of the tempered glass layer which is maintained at the temperature of 45° C. to 65° C. until the protection layer is integrally attached on the tempered glass layer, wherein the protection layer has a circular center portion formed above the central hole of the tempered glass layer;

[0016] (f) cutting excessive edges of the protection layer to a size identical to the tempered glass layer; and

[0017] (g) forming a center hole on the protection layer, which coaxially aligns with the central hole of the tempered glass layer.

[0018]FIG. 1 is a sectional view of the patio tabletop glass in accordance with the above preferred embodiment of the present invention.

[0019]FIG. 2 is a flow diagram of a manufacturing process for producing a patio tabletop glass in accordance with a preferred embodiment of the present invention.

[0020]FIG. 3 is a perspective view illustrating the cutting step in accordance with the above preferred embodiment of the present invention.

[0021]FIG. 4 is a sectional view illustrating how the protection layer is ensured to perfectly stick on the tempered glass layer in accordance with the above preferred embodiment.

[0022]FIG. 5 is a flow diagram of a process of forming the center hole on the protection layer in accordance with the above preferred embodiment of the present invention.

[0023] Referring to FIGS. 1 and 2, a preferred embodiment of the present invention is illustrated. As shown in FIG. 2, a patio tabletop glass 10 of the present invention comprises a tempered glass layer 11, a protection layer 12 and an adhesive layer 13. The tempered glass layer 11 has a predetermined shape, thickness and width size and a central hole 111 provided thereon. The protection layer 12 is made of polyvinyl chloride or polyester sheet having a thickness of 0.3 to 0.8 mm and a shape and width size identical to that of the tempered glass layer 11.

[0024] The tempered glass layer 11 is generally made of figured glass that has an uneven top surface 112 having specific decorative pattern. The protection layer 12 is integrally attached on the top surface 112 of the tempered glass layer 11 and has a center hole 121 formed thereon, wherein the center hole 121 of the protection layer 12 has an identical diameter of the central hole 111 and is coaxially aligned with the central hole 111 of the tempered glass layer 11. The adhesive layer, which has a preferred thickness between 0.1 to 0.2 mm and is made of acrylic adhesive and the like, is evenly applied between the top surface 112 of the tempered glass layer 11 and a bottom surface 122 of the protection layer 12 so as to integrally adhere the protection layer 12 with the tempered glass layer 11 to form an one piece body. Moreover, the tension of a periphery portion 123 of the protection layer 12 is increased to form a protective edge 124, i.e. the round edge of the center hole 121, which is made to extend around the central hole of the tempered glass layer which is the most weakened area because of the high concentrate stress occurred around the central hole, and to ensure the periphery portion 123 of the protection layer 12 around the center hole 121 securely attached around the central hole 111 on the tempered glass layer 11.

[0025] For mass production, as shown in FIGS. 1 to 5, the structure of patio tabletop glass 10 as described above can be made according to the following steps:

[0026] (a) Provide a plurality of the tempered glass layers 11 each having the predetermined shape and width size as well as the central hole 111 provided thereon.

[0027] The step (a) further comprises the steps of cutting large piece of glass board to form a circular shaped glass layer having the specific decorative pattern provided on at least the top surface 112, drilling the central hole 111 on the glass layer and tempering the glass layer by heating the glass layer to about 500° C.-550° C. and then immediately cooling down to 0° C.-40° C. to form the tempered glass layer 11.

[0028] (b) Fully clean at least the top surface 112 of each of the tempered glass layers 11 with neutral water having a pH of 7 so as to remove any possible oil thereon.

[0029] (c) Dry all cleaned tempered glass layers 11.

[0030] (d) Heat each of the tempered glass layers 11 entirely to a temperature between 45° C. to 65° C.

[0031] (e) Attach the protection layer 12 having a thickness of 0.3 to 0.8 mm and a width size larger than the tempered glass layer 11 on the top of the adhesive layer 13 of the tempered glass layer 11 by pressing the protection layer 12 against the top surface 112 of the tempered glass layer 11 which is maintained at the temperature of 45° C. to 65° C. until the protection layer 12 is integrally attached on the tempered glass layer 11, wherein the protection layer 11 has a circular center portion 120 formed above the central hole 111 of the tempered glass layer 11.

[0032] As shown in FIG. 2, the step (e) further comprises the following steps:

[0033] (e-1) Evenly apply a layer of acrylic adhesive or the like on the top surface 112 of each of the tempered glass layers 11 which temperature is maintained between 45° C. to 65° C. to form the adhesive layer 13 having the thickness of 0.1 to 0.2 mm.

[0034] (e-2) Provide a roll of continuous protection layer 12′ having the thickness of 0.3 to 0.8 mm and a width size larger than that of the tempered glass layers 11.

[0035] The bottom surface of the continuous protection layer 12′ may also provided with a layer of acrylic adhesive or the like to facilitate the continuous protection layer 12′ to adhere to the tempered glass layers 11.

[0036] (e-3) Feed one end of the protection layer 12′ and the plurality of tempered glass layers 11 one after one between a pair of parallel rubber rollers 21, 22, wherein the continuous protection layer 12′ is attached on the top of the adhesive layers 13 of the tempered glass layers 11 in overlapped manner. The pair of parallel rubber rollers 21, 22 are arranged to press the continuous protection layer 12′ against the top surfaces 111 of the tempered glass layers 11, which are still maintained at the temperature of 45° C. to 65° C., until the continuous protection layer 12′ is integrally adhered on the top surface 112 of each of the tempered glass layers 11.

[0037] (e-4) As shown in FIG. 3, cut off the continuous protection layer 12′ according to the number of the tempered glass layers 11 into a plurality of the protection layers 12.

[0038] (f) As shown in FIG. 3. cut away the excessive edges of each of the protection layers 12 to a size identical to the respective tempered glass layer 11.

[0039] (g) As shown in FIGS. 2 and 3, form the center hole 121 on each of the protection layers 12 to coaxially align with the central hole 112 of the respective tempered glass layer 11 to form the patio tabletop glass 10.

[0040] According to the present invention, the step (g) further comprises the steps of:

[0041] (g-1) pressing the center portion 120 of the protection layer 12 toward the central hole 111 of the tempered glass layer 11 that increases the tension of a peripheral portion 123 of the protection layer 12 attached around the central hole 111 of the tempered glass layer 11 to ensure the peripheral portion 123 of the protection layer 12 extending and attaching to an upper edge of the central hole 111 of the tempered glass layer 11; and

[0042] (g-2) grinding the upper edge of the central hole 111 of the tempered glass layer 11 until the center portion 120 of the protection layer 12 is separated from the protection layer 12 to form a center hole 121 coaxially aligned with the central hole 111 of the tempered glass layer 11.

[0043] The step (g), as shown in FIG. 5, is a specific step designed to form the center hole 121 for the present invention. It should be noted that the center portion 120 is not directly cut from the protection layer 12 to form the center hole 121. It is because if the center portion 120 is directly cut out from the protection layer 12, the peripheral edge of the center hole 121 will not be fittedly attached to the upper edge of the central hole 111, so that further grinding step may be required to remove the cutting edge of the center hole 121. Moreover, to directly cut out the center portion 120 from the protection layer 12 will frequently cause an elongated bubble popping up between the tempered glass layer 11 and the protective layer 12 and extending from the edge of the central hole to the peripheral edge of the tabletop glass.

[0044] According to the present invention, no cutting is required to form the center hole 121, wherein in the step (g-1), as shown in FIG. 5, a press mold 20, which has a round shaped presser head 21 at one end thereof, is used to coaxially press against the center portion 120 by pressing into the center portion 120 into the central hole 111 of the tempered glass layer 11. The inward pressing force of the pressing head 21 increases the tension of the peripheral portion 123 of the protection layer 12. Also, since the bottom surface 122 of the protection layer 12 may also provided with adhesive layer, the inward pressing force of the pressing head 21 will further press the peripheral portion 123 of the protection layer 12 to extend and attach to the upper edge of the central hole 111 of the tempered glass layer 11.

[0045] Then, in the step (g-2), a rotating sand wheel is used to grind at the position of the corresponding upper edge of the central hole 111 so as to reduce the thickness of the peripheral edge of the center portion 120 until the center portion 120 of the protection layer 12 is separated from the protection layer 12 to form a center hole 121 coaxially aligned with the central hole 111 of the tempered glass layer 11. To form the center hole 121 by the pressing and grinding steps in step (g) can, at the same time, substantially eliminate uneven adhering tension of the protection layer 12 to prevent the elongated bubbles popping up between the tempered glass layer 11 and the protective layer 12.

[0046] Alternatively, since the protection layer 12 is a thin film and most of the tempered glass layers 11 to be used to make the patio tabletop glass contain decorative patterns on the surfaces, as shown in FIG. 4, in order to ensure the protection layer 12 being completely attached on the tempered glass layer 11 under even tension, the step (e-3) can be modified to used a pair of hard rollers 21″, 22″ to substitute the pair of rubber rollers 21, 22. However, a pressure board 30, such as a cardboard or a soft pad made of foam or rubber material having a thickness of about 2 mm, should be placed on top of the protection layer 12 before feeding between the pair of hard rollers 21″, 22″, wherein the pressure board 30 can not only protect the protection layer 12 but also transfer the greater pressing force applied by the hard rollers 21″, 22″ to even pressure for attaching the protection layer 12 on the tempered glass layer 11.

[0047] In view of above, when the patio tabletop glass 10 is broken into pieces and particles, the top surfaces of each of the broken glass pieces and particles will still be individually attached to the protection layer 12 so as to prevent the broken glass pieces and particles from breaking apart and falling down. In other words, the present invention provides an effective way to solve the conventional glass breaking problem. Moreover, the manufacturing process of the patio tabletop glass is fast and inexpensive adapted for mass production.