Vacuum forming machine modular clamping frames

Claim 2

In a vacuum forming machine for molding a thermoplastic sheet about a suitable die and including a vacuum table adapted to support a die thereon and heating means positioned above said table and defining an oven adjacent which the plastic sheet is positioned for heating prior to forming; the combination therewith of a clamping frame assembly for securely supporting different sizes of thermoplastic sheets therein, one at a time, during heating and forming; said clamping frame assembly comprising a pair of complementary first and second substantially rectangular main clamping frames, means pivotally interconnecting said main clamping frames adjacent one edge portion thereof, a pair of complementary first and second auxiliary clamping frames within the respective first and second main clamping frames, said auxiliary clamping frames each comprising a first pair of front and rear spaced substantially parallel modular rails, and a second pair of spaced substantially parallel modular rails secured to and extending transversely of and between said first pair of rails, means releasably securing opposite ends of said first pair of modular rails of said first auxiliary clamping frame to opposite side portions of said first main clamping frame, means pivotally connecting said rear modular rail of said second auxiliary clamping frame to the adjacent rear modular rail of said first auxiliary clamping frame so that said second auxiliary clamping frame is movable about its pivot relative to said first auxiliary clamping frame and relative to both of said main clamping frames, and means for releasably clamping said first and second auxiliary clamping frames together for clampingly securing a thermoplastic sheet therebetween.

Claim 3

A vacuum forming machine according to claim 1, including means matingly releasably connecting one end portion of at least one of the rails of one of said second pairs to a respective one of the rails of the corresponding first pair, the other rail of said corresponding first pair having at least one cavity therein, and movable latch means carried by the other end portion of said one rail of said one second pair and adapted to fit in said cavity for releasably maintaining said last-named other end portion in predetermined relation to said other rail of said corresponding first pair.

Claim 4

A vacuum forming machine according to claim 1, including a pair of of pins projecting from one end of each of said second modular rails of said first auxiliary clamping frame, a corresponding one of said first modular rails having a plurality of pairs of apertures therein for selectively receiving corresponding pairs of said pins projecting from said last-named second rails, the other end of each last-named second rail having a longitudinally movable plunger thereon, and the other of said first modular rails of said first auxiliary clamping frame having a row of cavities therein for selectively receiving therein said plungers on said second rails of said first auxiliary clamping frame.

Claim 5

A vacuum forming machine according to claim 3, wherein each of said last-named second rails comprises an angle bar having substantially vertical and substantially horizontal flanges extending longitudinally thereof, said vertical flanges of said last-named second rails facing inwardly toward each other, each of said pairs of apertures in about one-half the length of said first modular rail of said first auxiliary clamping frame having a different positional relationship than each of said pairs of apertures in the other half of the length of the last-named first rail, the pair of pins of one of said last-named second rails also having a different positional relationship than the pair of pins of the other last-named seCond rail, and the positional relationship of the pairs of pins of said one and said other last-named second rails corresponding to that of the pairs of apertures in the respective one and other halves of the length of the last-named first rail.

Claim 6

In a vacuum forming machine for molding a thermoplastic sheet about a suitable die and including a vacuum table adapted to support a die thereon, and heating means positioned above said table and defining an oven adjacent which the plastic sheet is positioned for heating prior to forming; the improvement comprising a clamping frame assembly for securely supporting a thermoplastic sheet during heating and forming comprising upper and lower complementary substantially rectangular clamping frames adapted to clamp edge portions of a thermoplastic sheet therebetween, each frame including main front and rear rails, a pair of main opposing side rails connected to said front and rear rails, and means pivotally interconnecting said rear rails of said upper and lower frames, a plurality of modular structural members for adapting said rectangular clamping frames to accommodate smaller thermoplastic sheets therein of less area than the area encompassed by said rectangular clamping frames, said modular structural members comprising first and second lower modular rails for said lower clamping frame, means for releasably connecting each of said first and second lower modular rails to said lower clamping frame so as to extend between said main side rails and substantially parallel with said main front and rear rails and including a. means releasably connecting one end portion of each of said first and second lower modular rails to the inner surface of one of said main side rails of said lower clamping frame, b. a plurality of cavities in the inner surface of the opposite main side rail of said lower clamping frame, and c. movably latch means carried by the other end portion of each of said first and second lower modular rails, each of said latch means being adapted to fit in one of said cavities for releasably maintaining the associated lower modular rail in predetermined relation with respect to said opposite main side rail of said lower clamping frame, a pair of transverse lower modular rails extending transversely between said first and second lower modular rails, means detachably connecting opposite ends of said transverse lower modular rails to proximal surfaces of said first and second lower modular rails, first and second upper modular rails, means pivotally connecting said second upper modular rail to said second lower modular rail, a pair of transverse upper modular rails extending between and connected to said first and second upper modular rails such that said first and second upper rails and said pair of transverse upper rails respectively overlie said first and second lower modular rails and said pair of transverse lower modular rails, and means carried by said clamping frame for releasably clamping said upper modular rails toward said lower modular rails for clamping portions of a thermoplastic sheet therebetween.

Claim 7

In a vacuum forming machine for molding a thermoplastic sheet about a suitable die and including a vacuum table adapted to support a die thereon, and heating means positioned above said table and defining an oven adjacent which the plastic sheet is positioned for heating prior to forming; the improvement comprising a clamping frame assembly for securely supporting a thermoplastic sheet during heating and forming comprising upper and lower complementary substantially rectangular clamping frames adapted to clamp edge portions of a thermoplastic sheet therebetween, each frame including main front and rear rails, a pair of main opposing side rails connected to said front and rear rails, and means pivotally interconnecting said rear rails of said upper and lower frames, a plurality of modular structural members for adapting said rectangular clamping frames to accommodate smaller thermoplastic sheets therein of less area than the area encompassed by said rectangular clamping frames, said modular structural members comprising first and second lower modular rails for said lower clamping frame, means for releasably connecting each of said first and second lower modular rails to said lower clamping frame so as to extend between said main side rails and substantially parallel with said main front and rear rails and including a. means releasably connecting one end portion of each of said first and second lower modular rails to the inner surface of one of said main side rails of said lower clamping frame, b. a plurality of cavities in the inner surface of the opposite main side rail of said lower clamping frame, and c. movably latch means carried by the other end portion of each of said first and second lower modular rails, each of said latch means being adapted to fit in one of said cavities for releasably maintaining the associated lower modular rail in predetermined relation with respect to said opposite main side rail of said lower clamping frame, a pair of transverse lower modular rails extending transversely between said first and second lower modular rails, means detachably connecting opposite ends of said transverse lower modular rails to proximal surfaces of said first and second lower modular rails, first and second upper modular rails, means pivotally connecting said second upper modular rail to said second lower modular rail, a pair of transverse upper modular rails extending between and connected to said first and second upper modular rails such that said first and second upper rails and said pair of transverse upper rails respectively overlie said first and second lower modular rails and said pair of transverse lower modular rails, and means carried by said clamping frame for releasably clamping said upper modular rails toward said lower modular rails for clamping portions of a thermoplastic sheet therebetween.

Claim 8

A vacuum forming machine according to claim 5 wherein said means releasably connecting one end portion of each of said first and second lower modular rails to the inner surface of one of said main side rails includes a pair of pins projecting from said one end portion of each of said first and second lower modular rails, and a plurality of longitudinally spaced pairs of apertures in the inner surface of said one of said main side rails for selectively matingly receiving said pair of pins therein.

Claim 9

A vacuum forming machine according to claim 5 wherein said means releasably connecting one end portion of each of said first and second lower modular rails to the inner surface of one of said main side rails includes a pair of pins projecting from said one end portion of each of said first and second lower modular rails with the pair of pins of said first lower modular rail having a positional orientation different from that of the pair of pins of said second lower modular rail, and a plurality of longitudinally spaced pairs of apertures in said inner surface of said one of said main side rails for selectively matingly receiving said pair of pins therein and with each of said pairs of apertures in about a first half of the length of said one main side rail having a positional orientation different from that of the pairs of apertures in about the second half of the length of said one main side rail, said positional orientation of said pairs of pins of said first and second lower modular rails corresponding to that of the pairs of apertures in the respective first and second halves of the length of said one main side rail.