US3705932A - Method for the manufacture of hollow plastic articles - Google Patents

Method for the manufacture of hollow plastic articles Download PDF

Info

Publication number
US3705932A
US3705932A US3705932DA US3705932A US 3705932 A US3705932 A US 3705932A US 3705932D A US3705932D A US 3705932DA US 3705932 A US3705932 A US 3705932A
Authority
US
United States
Prior art keywords
sheet
table tennis
ball
tennis ball
halves
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
Inventor
Norman Ashcroft Hurst
Thomas Edward Horace Gray
James Jones-Hinton
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Application granted granted Critical
Publication of US3705932A publication Critical patent/US3705932A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
    • B29C65/78—Means for handling the parts to be joined, e.g. for making containers or hollow articles, e.g. means for handling sheets, plates, web-like materials, tubular articles, hollow articles or elements to be joined therewith; Means for discharging the joined articles from the joining apparatus
    • B29C65/7858—Means for handling the parts to be joined, e.g. for making containers or hollow articles, e.g. means for handling sheets, plates, web-like materials, tubular articles, hollow articles or elements to be joined therewith; Means for discharging the joined articles from the joining apparatus characterised by the feeding movement of the parts to be joined
    • B29C65/7861—In-line machines, i.e. feeding, joining and discharging are in one production line
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
    • B29B13/00—Conditioning or physical treatment of the material to be shaped
    • B29B13/02—Conditioning or physical treatment of the material to be shaped by heating
    • B29B13/023—Half-products, e.g. films, plates
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C51/00—Shaping by thermoforming, i.e. shaping sheets or sheet like preforms after heating, e.g. shaping sheets in matched moulds or by deep-drawing; Apparatus therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C51/00—Shaping by thermoforming, i.e. shaping sheets or sheet like preforms after heating, e.g. shaping sheets in matched moulds or by deep-drawing; Apparatus therefor
    • B29C51/26—Component parts, details or accessories; Auxiliary operations
    • B29C51/44—Removing or ejecting moulded articles
    • B29C51/445—Removing or ejecting moulded articles from a support after moulding, e.g. by cutting
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
    • B29C65/02—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
    • B29C65/78—Means for handling the parts to be joined, e.g. for making containers or hollow articles, e.g. means for handling sheets, plates, web-like materials, tubular articles, hollow articles or elements to be joined therewith; Means for discharging the joined articles from the joining apparatus
    • B29C65/7841—Holding or clamping means for handling purposes
    • B29C65/7847—Holding or clamping means for handling purposes using vacuum to hold at least one of the parts to be joined
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/01—General aspects dealing with the joint area or with the area to be joined
    • B29C66/05—Particular design of joint configurations
    • B29C66/10—Particular design of joint configurations particular design of the joint cross-sections
    • B29C66/13—Single flanged joints; Fin-type joints; Single hem joints; Edge joints; Interpenetrating fingered joints; Other specific particular designs of joint cross-sections not provided for in groups B29C66/11 - B29C66/12
    • B29C66/131—Single flanged joints, i.e. one of the parts to be joined being rigid and flanged in the joint area
    • B29C66/1312—Single flange to flange joints, the parts to be joined being rigid
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/50—General aspects of joining tubular articles; General aspects of joining long products, i.e. bars or profiled elements; General aspects of joining single elements to tubular articles, hollow articles or bars; General aspects of joining several hollow-preforms to form hollow or tubular articles
    • B29C66/51—Joining tubular articles, profiled elements or bars; Joining single elements to tubular articles, hollow articles or bars; Joining several hollow-preforms to form hollow or tubular articles
    • B29C66/54—Joining several hollow-preforms, e.g. half-shells, to form hollow articles, e.g. for making balls, containers; Joining several hollow-preforms, e.g. half-cylinders, to form tubular articles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/80—General aspects of machine operations or constructions and parts thereof
    • B29C66/81—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps
    • B29C66/814—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps characterised by the design of the pressing elements, e.g. of the welding jaws or clamps
    • B29C66/8141—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps characterised by the design of the pressing elements, e.g. of the welding jaws or clamps characterised by the surface geometry of the part of the pressing elements, e.g. welding jaws or clamps, coming into contact with the parts to be joined
    • B29C66/81411—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps characterised by the design of the pressing elements, e.g. of the welding jaws or clamps characterised by the surface geometry of the part of the pressing elements, e.g. welding jaws or clamps, coming into contact with the parts to be joined characterised by its cross-section, e.g. transversal or longitudinal, being non-flat
    • B29C66/81421—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps characterised by the design of the pressing elements, e.g. of the welding jaws or clamps characterised by the surface geometry of the part of the pressing elements, e.g. welding jaws or clamps, coming into contact with the parts to be joined characterised by its cross-section, e.g. transversal or longitudinal, being non-flat being convex or concave
    • B29C66/81423—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps characterised by the design of the pressing elements, e.g. of the welding jaws or clamps characterised by the surface geometry of the part of the pressing elements, e.g. welding jaws or clamps, coming into contact with the parts to be joined characterised by its cross-section, e.g. transversal or longitudinal, being non-flat being convex or concave being concave
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/80—General aspects of machine operations or constructions and parts thereof
    • B29C66/81—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps
    • B29C66/816—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps characterised by the mounting of the pressing elements, e.g. of the welding jaws or clamps
    • B29C66/8161—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps characterised by the mounting of the pressing elements, e.g. of the welding jaws or clamps said pressing elements being supported or backed-up by springs or by resilient material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/80—General aspects of machine operations or constructions and parts thereof
    • B29C66/82—Pressure application arrangements, e.g. transmission or actuating mechanisms for joining tools or clamps
    • B29C66/822—Transmission mechanisms
    • B29C66/8221—Scissor or lever mechanisms, i.e. involving a pivot point
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/80—General aspects of machine operations or constructions and parts thereof
    • B29C66/83—General aspects of machine operations or constructions and parts thereof characterised by the movement of the joining or pressing tools
    • B29C66/832—Reciprocating joining or pressing tools
    • B29C66/8322—Joining or pressing tools reciprocating along one axis
    • B29C66/83221—Joining or pressing tools reciprocating along one axis cooperating reciprocating tools, each tool reciprocating along one axis
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/80—General aspects of machine operations or constructions and parts thereof
    • B29C66/84—Specific machine types or machines suitable for specific applications
    • B29C66/843—Machines for making separate joints at the same time in different planes; Machines for making separate joints at the same time mounted in parallel or in series
    • B29C66/8432—Machines for making separate joints at the same time mounted in parallel or in series
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C2793/00—Shaping techniques involving a cutting or machining operation
    • B29C2793/0009—Cutting out
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
    • B29C65/02—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
    • B29C65/04—Dielectric heating, e.g. high-frequency welding, i.e. radio frequency welding of plastic materials having dielectric properties, e.g. PVC
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/01—General aspects dealing with the joint area or with the area to be joined
    • B29C66/05—Particular design of joint configurations
    • B29C66/10—Particular design of joint configurations particular design of the joint cross-sections
    • B29C66/11—Joint cross-sections comprising a single joint-segment, i.e. one of the parts to be joined comprising a single joint-segment in the joint cross-section
    • B29C66/114—Single butt joints
    • B29C66/1142—Single butt to butt joints
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/80—General aspects of machine operations or constructions and parts thereof
    • B29C66/84—Specific machine types or machines suitable for specific applications
    • B29C66/843—Machines for making separate joints at the same time in different planes; Machines for making separate joints at the same time mounted in parallel or in series
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
    • B29L2031/00—Other particular articles
    • B29L2031/54—Balls
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
    • B29L2031/00—Other particular articles
    • B29L2031/54—Balls
    • B29L2031/542—Christmas balls

Definitions

  • ABSTRACT l4 I966, abandoned, and Ser. No. 601,592, A method for manufacturing table tennis balls. The Dec. 14, 1966, abandoned.
  • PATENTEDnEc 12 I972 SHEET lUUF18 SHEET IBUF 18 PKTE'N'TEDHH: 12 m2 METHOD FOR THE MANUFACTURE OF HOLLOW PLASTIC ARTICLES
  • This invention relates to methods for the manufacture of hollow plastic articles particularly table tennis balls and is a continuation in part of our US. patent applications Nos. 601,591 and 601,592, both now abandoned.
  • Table tennis balls of the best quality are a precision product which must meet strict standards of weight and diameter and must be as nearly perfectly spherical as possible.
  • table tennis balls have generally been made from cellulose nitrate by a method which involved forming ball halves from sheets of that material and attaching the ball halves together by treating the edges of the halves with solution one half being provided with a lip which fits inside the other half.
  • a method of manufacturing table'tennis balls comprises forming the two halves of a table tennis ball in a sheet of thermoplastic material, dividing the sheet into two separate parts each of which contains one half of said table tennis ball, invening one part of the sheet relative to the other part of the sheet by means of movable sheet gripping means and locating said two parts adjacent one another in superposed relationship so that the two halves of said table tennis ball are aligned in substantially the relative positions they occupy in the finished table tennis ball, joining said two parts together to form the table tennis ball and removing the table tennis ball from the sheet.
  • apparatus for use in the manufacture of hollow plastics articles comprises parting means for dividing the sheet into two separate parts each containing one half of the article, supporting means for the parts of the sheet, means for gripping one part of the sheet, means for producing relative movement between said one part of the sheet and its supporting means to move said one part of the sheet out of contact with its supporting means, means for inverting said one part of the sheet while it is out of contact with its supporting means, and means for locating the two parts together on the supporting means so that the halves of the article are in substantially the relative positions they occupy in the finished article.
  • the supporting means for the parts of the sheet is formed in two sections, one for each of the parts of the sheet, and the two sections are relatively movable to enable one part of the sheet to be moved out of contact with its supporting means to permit that part of the sheet to be inverted.
  • the method of this invention enables table tennis balls to be made to very high standards of precision economically and with a lower proportion of sub-standard balls than has previously been achieved.
  • FIGS. 1A, 1B, 1C together are a plan view of an apparatus for carrying out the method of invention.
  • FIG. 2 is a partial view of the apparatus in the direction of Arrow A of FIG. 1.
  • FIG. 3 is a partial view of the apparatus in the direction of Arrow B of FIG. 1.
  • FIGS. 4A, 48 together are a partial view in cross-section of the apparatus taken along the line C-C of FIG. 1
  • FIG. 5 is partial front elevation, partly in section, of the apparatus taken along the line D-D of FIG. 1.
  • FIG. 6 is a view partly shown looking in the direction of Arrow E of FIG. 5.
  • FIG. 7 is a cross-sectional view of the apparatus shown in FIG. 1 and looking in the direction of Arrow F of FIG. 1.
  • FIG. 8 is a partial view, partly broken away and sectional, taken in the direction of Arrow G of FIG. 7.
  • FIGS. 9A, 93 together are a partial view in cross-section, taken along the line H-H of FIG. 1.
  • FIG. 10 is a partial front view of the apparatus of FIG. 9 in the direction of Arrow K of FIG. 9.
  • FIGS. 11A, 11B and 11C together are views, partly in cross-section, of the apparatus, viewed along the line L-L of FIG. I and FIGS. 12A, 12B together are a view on Arrow M of FIG. 1 1B.
  • a table-tennis ball making machine is mounted on a rigid floor mounted frame 1 which has an invented T- shape cross-section.
  • Located on the front face 2 of the vertical leg 3 of the frame are eight stations at equidistant centers.
  • each station is apparatus for performing one or more operations required during the manufacture of a table-tennis ball from a sheet of thermoplastic material.
  • the stations are definitively titled feed station 100, heating station 200, forming station 300, cutting and doubling station 400, welding station 500, idle station 600, cropping and trimming station 700, and discharge station 800.
  • Transferring means are provided for moving a sheet of material from one station to the next.
  • Rotatably mounted on the base 4 of the frame at the rear of the central leg 3 is a camshaft 5 which extends the length of the frame.
  • a plurality of cams is mounted on the camshaft and these are connected by cam followers to the apparatus and the transferring means to control the sequence of operations of the machine during manufacture.
  • the camshaft is connected to a reduction gearbox 6 which is driven by a constant speed electric motor 7 so that the camshaft 5 rotates at a constant angular velocity.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)

Abstract

A method for manufacturing table tennis balls. The halves of a ball are formed in a single sheet and the sheet is separated to separate the formed halves of the ball. One of the portions of the sheet containing a ball half is inverted relative to the other and the portions are aligned so as to align the ball halves the rein. The sheet portions are then welded together to join the ball halves and the completed ball is removed from the joined sheet portions.

Description

United States Patent Hurst et al.
[56] References Cited UNITED STATES PATENTS METHOD FOR THE MANUFACTURE OF HOLLOW PLASTIC ARTICLES WXXX M MM M 0 II I "/46 x5 1 m m "nu mnu m m "m um v H mm m b e m a 0W TRSJ 7048 3526 9999 11]] NN 11 [22] Filed: May 12, 1970 Primary Examiner-Robert F. White Assistant Examiner-J. H. Silbaugh Attorney-Rauber & Lazar [21] Appl. No.: 36,507
Related (1.8. Application Data [63] Continuation-impart of Ser. Nos. 601,591, Dec.
ABSTRACT l4, I966, abandoned, and Ser. No. 601,592, A method for manufacturing table tennis balls. The Dec. 14, 1966, abandoned.
halves of a ball are formed in a single sheet and the sheet is separated to separate the formed halves of the 7 Claims, 19 Drawing Figures mmmtmm 3105.932
SHEET 01 0F 18 AIM/my Auk-Ron" A an-w li msfbwmo Home! GRAY WMLM FATENTEDBEB 12 m2 SHEET DZUF 18 PATENIEDumzm 3.705.932 saw our 18 PMENTEDHEB 12 1912 SHEET DSBF 18 PATENTED DEC 1-2 1912 SHEET IUUF 18 FIG. 8
P'A'TENTED nEc 12 m2 SHEET 130F 18 FIG. 10
PATENTEDnEc 12 I972 SHEET lUUF18 SHEET IBUF 18 PKTE'N'TEDHH: 12 m2 METHOD FOR THE MANUFACTURE OF HOLLOW PLASTIC ARTICLES This invention relates to methods for the manufacture of hollow plastic articles particularly table tennis balls and is a continuation in part of our US. patent applications Nos. 601,591 and 601,592, both now abandoned.
Table tennis balls of the best quality are a precision product which must meet strict standards of weight and diameter and must be as nearly perfectly spherical as possible.
In the past table tennis balls have generally been made from cellulose nitrate by a method which involved forming ball halves from sheets of that material and attaching the ball halves together by treating the edges of the halves with solution one half being provided with a lip which fits inside the other half.
The fitting together of the halves is carried out largely by hand and the method suffers from the disadvantages that the cellulose nitrate and solvent used are highly inflammable and the accuracy of the method is poor so that a high proportion of low standard balls is produced, the balls having to be carefully graded.
Other types of ball which do not need to be made to a precise standard, e.g., hollow rubber balls, have been made by pressing ball halves in sheets of rubber and folding the sheets of rubber to bring the halves together.
This method cannot be applied, however, to the manufacture of table tennis balls since the stiff plastics materials needed to be used cannot be folded satisfactorily to give the required precision.
It has been proposed to make other low precision products, e.g., Christmas tree balls, by forming halves of the article in separate sheets of material and placing together the separate sheets to unite the halves of the article. This method produces inferior table tennis balls, however, since small differences in the thickness of the separate plastic sheets used cause the balls to be unbalanced.
According to the invention a method of manufacturing table'tennis balls comprises forming the two halves of a table tennis ball in a sheet of thermoplastic material, dividing the sheet into two separate parts each of which contains one half of said table tennis ball, invening one part of the sheet relative to the other part of the sheet by means of movable sheet gripping means and locating said two parts adjacent one another in superposed relationship so that the two halves of said table tennis ball are aligned in substantially the relative positions they occupy in the finished table tennis ball, joining said two parts together to form the table tennis ball and removing the table tennis ball from the sheet.
According to the invention also apparatus for use in the manufacture of hollow plastics articles comprises parting means for dividing the sheet into two separate parts each containing one half of the article, supporting means for the parts of the sheet, means for gripping one part of the sheet, means for producing relative movement between said one part of the sheet and its supporting means to move said one part of the sheet out of contact with its supporting means, means for inverting said one part of the sheet while it is out of contact with its supporting means, and means for locating the two parts together on the supporting means so that the halves of the article are in substantially the relative positions they occupy in the finished article.
Preferably the supporting means for the parts of the sheet is formed in two sections, one for each of the parts of the sheet, and the two sections are relatively movable to enable one part of the sheet to be moved out of contact with its supporting means to permit that part of the sheet to be inverted.
The method of this invention enables table tennis balls to be made to very high standards of precision economically and with a lower proportion of sub-standard balls than has previously been achieved.
The invention will now be described, by the way of example only with reference to the accompanying drawings in which:
FIGS. 1A, 1B, 1C together are a plan view of an apparatus for carrying out the method of invention.
FIG. 2 is a partial view of the apparatus in the direction of Arrow A of FIG. 1.
FIG. 3 is a partial view of the apparatus in the direction of Arrow B of FIG. 1.
FIGS. 4A, 48 together are a partial view in cross-section of the apparatus taken along the line C-C of FIG. 1
FIG. 5 is partial front elevation, partly in section, of the apparatus taken along the line D-D of FIG. 1.
FIG. 6 is a view partly shown looking in the direction of Arrow E of FIG. 5.
FIG. 7 is a cross-sectional view of the apparatus shown in FIG. 1 and looking in the direction of Arrow F of FIG. 1.
FIG. 8 is a partial view, partly broken away and sectional, taken in the direction of Arrow G of FIG. 7.
FIGS. 9A, 93 together are a partial view in cross-section, taken along the line H-H of FIG. 1.
FIG. 10 is a partial front view of the apparatus of FIG. 9 in the direction of Arrow K of FIG. 9.
FIGS. 11A, 11B and 11C together are views, partly in cross-section, of the apparatus, viewed along the line L-L of FIG. I and FIGS. 12A, 12B together are a view on Arrow M of FIG. 1 1B.
A table-tennis ball making machine is mounted on a rigid floor mounted frame 1 which has an invented T- shape cross-section. Located on the front face 2 of the vertical leg 3 of the frame are eight stations at equidistant centers. In each station is apparatus for performing one or more operations required during the manufacture of a table-tennis ball from a sheet of thermoplastic material. The stations are definitively titled feed station 100, heating station 200, forming station 300, cutting and doubling station 400, welding station 500, idle station 600, cropping and trimming station 700, and discharge station 800. Transferring means are provided for moving a sheet of material from one station to the next. Rotatably mounted on the base 4 of the frame at the rear of the central leg 3 is a camshaft 5 which extends the length of the frame. A plurality of cams is mounted on the camshaft and these are connected by cam followers to the apparatus and the transferring means to control the sequence of operations of the machine during manufacture. The camshaft is connected to a reduction gearbox 6 which is driven by a constant speed electric motor 7 so that the camshaft 5 rotates at a constant angular velocity.
The transferring means and the apparatus located in each station will now be described in more detail.
Transferring Means

Claims (7)

1. A method of manufacturing a table tennis ball comprising forming the two halves of a table tennis ball in a single, generally planar sheet of stiff thermoplastic material, dividing the sheet into two separate parts each of which contains one half of said table tennis ball, inverting one part of the sheet relative to the other part of the sheet by means of movable sheet gripping means and locating said two parts adjacent one another in superposed relationship so that the two halves of said table tennis ball are aligned in substantially the relative positions they occupy in the finished table tennis ball, joining said two parts together to form the table tennis ball and removing the table tennis ball from the sheet.
2. A method according to claim 1 in which the sheet is divided into two equal parts by means of a knife.
3. A method according to claim 1 in which one part of the sheet is held by sheet gripping means and inverted relative to the other part of the sheet by rotating said gripping means.
4. A method according to claim 3 in which the inverted one part of the sheet is located on a support member by engagement of at least one ball half with a corresponding sized hole in the support member.
5. A method according to claim 3 in which the other part of the sheet is located in superposed relationship with said inverted one part of the sheet by moving said other part of the sheet in the plane of said sheet relative to said inverted one part of the sheet by means of a pusher member.
6. A method according to claim 5 in which a locating means is provided up to which said other part of the sheet is pushed by the pusher member to locate said other part of the sheet in superposed relationship with said inverted one part of the sheet.
7. A method according to claim 6 in which the locating means is a stop.
US3705932D 1970-05-12 1970-05-12 Method for the manufacture of hollow plastic articles Expired - Lifetime US3705932A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US3650770A 1970-05-12 1970-05-12

Publications (1)

Publication Number Publication Date
US3705932A true US3705932A (en) 1972-12-12

Family

ID=21888965

Family Applications (1)

Application Number Title Priority Date Filing Date
US3705932D Expired - Lifetime US3705932A (en) 1970-05-12 1970-05-12 Method for the manufacture of hollow plastic articles

Country Status (1)

Country Link
US (1) US3705932A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2004026562A1 (en) * 2002-09-18 2004-04-01 Dart Container Corporation Method and apparatus for assembling a closure tab to a lid
US10351308B1 (en) 2016-09-22 2019-07-16 Lidworks, Co. Disposable cup lid
US10940980B1 (en) 2016-09-22 2021-03-09 Lidworks, Co Disposable cup lid
US11472614B2 (en) 2016-09-22 2022-10-18 Lidworks, Co. Disposable cup lid

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1514183A (en) * 1922-06-19 1924-11-04 Miller Rubber Co Machine for making hollow rubber articles
US2081777A (en) * 1934-01-10 1937-05-25 Talalay Josef Anton Manufacture of hollow rubber articles
US2513052A (en) * 1945-12-11 1950-06-27 Roberts Robert Eldon Method and apparatus for making hollow plastic articles
US3411974A (en) * 1964-10-14 1968-11-19 Dunlop Co Ltd Apparatus for forming hollow plastic articles

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1514183A (en) * 1922-06-19 1924-11-04 Miller Rubber Co Machine for making hollow rubber articles
US2081777A (en) * 1934-01-10 1937-05-25 Talalay Josef Anton Manufacture of hollow rubber articles
US2513052A (en) * 1945-12-11 1950-06-27 Roberts Robert Eldon Method and apparatus for making hollow plastic articles
US3411974A (en) * 1964-10-14 1968-11-19 Dunlop Co Ltd Apparatus for forming hollow plastic articles

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2004026562A1 (en) * 2002-09-18 2004-04-01 Dart Container Corporation Method and apparatus for assembling a closure tab to a lid
US20040111858A1 (en) * 2002-09-18 2004-06-17 Dart Container Corporation Method and apparatus for assembling a closure tab to a lid
JP2005538875A (en) * 2002-09-18 2005-12-22 ダート コンテナー コーポレーション Method and apparatus for assembling a lid tab into a lid
US20060005369A1 (en) * 2002-09-18 2006-01-12 Dart Container Corporation Method and apparatus for assembling a closure tab to a lid
US20070294886A1 (en) * 2002-09-18 2007-12-27 Dart Container Corporation Method and Apparatus for Assembling a Closure Tab to a Lid
US7353582B2 (en) 2002-09-18 2008-04-08 Dart Container Corporation Method for assembling a closure tab to a lid
AU2003272508B2 (en) * 2002-09-18 2008-11-20 Dart Container Corporation Method and apparatus for assembling a closure tab to a lid
US7523534B2 (en) * 2002-09-18 2009-04-28 Whirlpool Corporation Method for assembling a closure tab to a lid
US7676909B2 (en) 2002-09-18 2010-03-16 Dart Container Corporation Apparatus for assembling a closure tab to a lid
US10351308B1 (en) 2016-09-22 2019-07-16 Lidworks, Co. Disposable cup lid
US10940980B1 (en) 2016-09-22 2021-03-09 Lidworks, Co Disposable cup lid
US11472614B2 (en) 2016-09-22 2022-10-18 Lidworks, Co. Disposable cup lid

Similar Documents

Publication Publication Date Title
ES409752A1 (en) Machine for producing a plastic-covered glass container
CA2632546A1 (en) Heat-insulating container and apparatus for producing the same
IE44215B1 (en) A process and apparatus for the manufacture of filled,closed containers
US3705932A (en) Method for the manufacture of hollow plastic articles
EP0336988A3 (en) Apparatus for forming a blown bottle with a handle and method of forming the same
JPS605164B2 (en) Injection molding machine
US2454194A (en) Method for making a holder of plastic material for pocket combs and the like
US3071812A (en) Rotary molding machine
US3377899A (en) Plastic bottle trimming machine
US3853655A (en) Method of and fixture for welding flexible members into a frame
FR2175227B3 (en)
US3608146A (en) Apparatus for forming plastic tubular articles
CN208375883U (en) Flashing lamp lens process units
US2470638A (en) Apparatus for working plastic material
JPH0516815B2 (en)
US3635636A (en) Apparatus for forming hollow bodies
US4208955A (en) Container manufacturing apparatus and method
US3153433A (en) Method of making bowls and the like
US3627505A (en) Glass tube cutting machine with end polisher
US3936345A (en) Apparatus for welding flexible members into a frame
US2942532A (en) Apparatus for forming and affixing a divider in a box
JPH0780895A (en) Cutting device for gate of molded member
GB2205269A (en) Apparatus for trimming a tubular article
US2558318A (en) Apparatus for trimming appendages for pottery ware
US1485590A (en) Machine for shaping sheet materials