Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
303 words
An apparatus for injection molding a product having a partly thin portion comprising: a molding die including a male die and a female die for defining a cavity therebetween, said cavity having a volume larger than a volume of the product, and said molding die further including a gate for injecting a molten resin material from an injection molding machine into said cavity; a slide block disposed in one of said male die and said female die and having in cross section a dimension corresponding to a dimension of the thin portion of the product, and said slide block being movable between a retracted position whereat the volume of said cavity is substantially maintained and an advanced position to project into said cavity thereby reducing the volume of said cavity for forming the thin portion; drive means for moving said slide block, said drive means being adapted to advance said slide block before the resin material injected into said cavity is solidified; a hollow space formed in said molding die and communicating with said cavity for permitting an excess of the resin material to be discharged from said cavity into said hollow space during the advance of said slide block; a closure member fitted in said hollow space for normally closing the same; and closure member drive means comprising spring means for urging said closure member to a retracted position and a power drive unit for maintaining said closure member in an advanced position against said spring means, said closure member driving said closure member in synchronism with said slide block drive means, whereby said closure member is retracted to open said hollow space substantially simultaneously with the advance of said slide block and is advanced to reduce a volume of said hollow space immediately after said slide block reaches said advanced position.
Claim 2
Independent Claim
303 words
An apparatus for injection molding a product having a partly thin portion comprising: a molding die including a male die and a female die for defining a cavity therebetween, said cavity having a volume larger than a volume of the product, and said molding die further including a gate for injecting a molten resin material from an injection molding machine into said cavity; a slide block disposed in one of said male die and said female die and having in cross section a dimension corresponding to a dimension of the thin portion of the product, and said slide block being movable between a retracted position whereat the volume of said cavity is substantially maintained and an advanced position to project into said cavity thereby reducing the volume of said cavity for forming the thin portion; drive means for moving said slide block, said drive means being adapted to advance said slide block before the resin material injected into said cavity is solidified; a hollow space formed in said molding die and communicating with said cavity for permitting an excess of the resin material to be discharged from said cavity into said hollow space during the advance of said slide block; a closure member fitted in said hollow space for normally closing the same; and closure member drive means comprising spring means for urging said closure member to a retracted position and a power drive unit for maintaining said closure member in an advanced position against said spring means, said closure member driving said closure member in synchronism with said slide block drive means, whereby said closure member is retracted to open said hollow space substantially simultaneously with the advance of said slide block and is advanced to reduce a volume of said hollow space immediately after said slide block reaches said advanced position.
Claim 3
Dependent Claim
45 words
An apparatus as claimed in claim 1, wherein said gate comprising a pin point gate opening substantially at a center of said cavity and said hollow space is formed adjacent said cavity, and further comprising a passage for connecting said cavity to said hollow space.
Claim 4
Dependent Claim
14 words
An apparatus as claimed in claim 2, wherein said passage is an inverted L-shape.
Claim 5
Dependent Claim
41 words
An apparatus as claimed in claim 1, wherein said gate comprises a side gate opening at a periphery of said cavity and connected to the injection molding machine through a runner, and wherein said hollow space is formed adjacent said runner.
Claim 6
Dependent Claim
45 words
An apparatus as claimed in claim 4, further comprising a passage for connecting said runner to said hollow space, said passage having a dimension smaller than a dimension of said side gate for increasing resistance to flow of the resin material into said hollow space.
Claim 7
Dependent Claim
37 words
An apparatus as claimed in claim 1, wherein said slide block drive means comprises a shaft connected to said slide block at the end opposite to said cavity and an actuator for causing said shaft to reciprocate.
Claim 8
Dependent Claim
74 words
An apparatus as claimed in claim 1, wherein said slide block drive means comprises spring means for urging said slide block to said retracted position, a beveled end surface of said slide block, a rod member extending perpendicularly to said slide block and having a slant surface abutting said beveled end surface whereby the forward movement of said rod member advances said slide block, and an actuator for causing said rod member to reciprocate.
Claim 9
Dependent Claim
58 words
An apparatus as claimed in claim 1, wherein said drive means includes a reciprocating rod member having a first slant surface adapted to advance said slide block upon forward movement of said rod member and a second slant surface of said rod member for permitting said closure member to retract upon said forward movement of said rod member.
Claim 10
Dependent Claim
36 words
An apparatus as claimed in claim 1, wherein said power drive unit includes a hydraulic cylinder and a piston connected at one end of said hydraulic cylinder and at the other end to said closure member.