Thread-rolling machine with rotatable rolling plates

Abstract

A thread-rolling machine includes a vertical rotating shaft journalled on a machine base, and a thread-rolling unit. The thread-rolling unit includes a plurality of angularly equidistant rotatable rolling plates fixed on the rotating shaft, and a plurality of angularly equidistant fixed rolling plates fixed on the machine base and disposed around the rotatable rolling plates. During rotation of the rotating shaft, nail-shaped blanks are fed simultaneously onto the thread-rolling unit. Each of the blanks is rolled between a respective one of the rotatable rolling plates and a respective one of the fixed rolling plates, thereby forming a bolt.

Description

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to a thread-rolling machine, and more particularly to a rotating type thread-rolling machine, which includes a plurality of rotatable rolling plates and a plurality of fixed rolling plates, between which a plurality of blanks can be processed simultaneously.

[0003] 2. Description of the Related Art

[0004] Referring to FIGS. 1 and 2, a reciprocating type conventional thread-rolling machine 1 is shown to include a machine base 11 a vibrating unit 12, a channel member 13 that has a U-shaped cross-section, a flywheel 14, a linkage 15, a push plate 16, a driving wheel 17, a link 18, a movable rolling plate 19, a mounting member 20 and a fixed rolling plate 21. A plurality of headed nail-shaped blanks 121 are fed from the vibrating unit 12 into the channel member 13 so as to move into a space between the mounting member 20 and the movable rolling plate 19. When the flywheel 14 is driven, the driving wheel 17 rotates to reciprocate the movable rolling plate 19 along a guiding member 110 that has an inverted U-shaped cross-section. Under such conditions, the flywheel 14 activates the linkage 15 such that the push plate 16 pushes the blanks 121 from the channel member 13 onto the movable rolling plate 19 one by one at a time interval. Subsequently, one of the blanks 121 is carried on and moves with the movable rolling plate 19 each time to press against the fixed rolling plate 21. Each of the movable rolling plate 19 and the fixed rolling plate 21 is formed with a plurality of inclined parallel ribs (not shown) that can press into the blanks 121, thereby forming helical grooves (not shown) on the blanks 121.

[0005] Some of the disadvantages of the aforesaid conventional thread-rolling machine 1 are as follows:

[0006] (1) The production rate of the machine 1 is severely limited:

[0007] During reciprocal movement of the movable rolling plate 19, the blanks 121 are processed only when the former moves from the position shown by the solid lines in FIG. 2 to that shown by the phantom lines in FIG. 2. That is to say, no thread-rolling action is performed during movement of the movable rolling plate 19 from the position shown by the phantom lines in FIG. 2 to that shown by the solid lines in FIG. 2, thereby resulting in a low production rate of the machine 1.

[0008] (2) There is a need for a relatively high power during the thread rolling operation:

[0009] In order to form bolts from the blanks 121, it is necessary to drive the flywheel 14, the linkage 15, the push plate 16, the driving wheel 17, the link 18 and the movable rolling plate 19, thereby resulting in a power-consuming process.

[0010] (3) The structure of the machine 1 is relatively complex:

[0011] The machine 1 consists of numerous elements, thereby resulting in a relatively complex structure, which will increase the manufacturing costs.

[0012] (4) It is dangerous to check if the blanks 121 are processed well:

[0013] In the art, a person responsible for quality control is required to check the quality of the bolt products during the thread rolling operation, and usually receives the bolts dropping from the movable rolling plate 19 and the fixed rolling plate 21 with one hand that wears a glove. The glove may come onto contact with and be drawn by the movable rolling plate 19 to move, thereby hurting the hand of the person.

[0014] (5) The height of the movable rolling plate 19 is also limited:

[0015] The machine 1 can process the blank 121 to form a bolt with a threaded section, which has a length that is not longer than the height of the movable rolling plate 19. However, the height of the movable rolling plate 19 is limited by the size of the guiding member 110, thereby reducing the applicable range of the machine 1.

[0016] (6) The noise incurred during the thread rolling operation is relatively large:

[0017] The moving parts of the machines 1 are numerous, thereby resulting in a comparatively noisy thread rolling operation.

SUMMARY OF THE INVENTION

[0018] An object of this invention is to provide a highly efficient rotating type thread-rolling machine, which has a simple structure, thereby resulting in a power-saving thread rolling operation.

[0019] Another object of this invention is to provide a thread-rolling machine with a plurality of bolt-guiding plates, which can prevent injury to one hand of a person responsible for quality control that accepts the bolt products dropping from the rolling plates when he or she checks the quality of the products during the thread rolling operation of the machine.

[0020] Still another object of this invention is to provide a rotating type thread-rolling machine with replaceable rotatable rolling plates, which have a height that can be selected optionally according to the desired length of the bolt products.

[0021] Yet another object of this invention is to provide a rotating type thread-rolling machine, which can reduce noise incurred during the thread rolling operation of the machine.

[0022] According to this invention, a thread-rolling machine includes a machine base, a vertical rotating shaft journalled on the machine base, a thread-rolling unit and a plurality of feeding units. The thread-rolling unit includes a plurality of angularly equidistant rotatable rolling plates disposed fixedly on the rotating shaft, and a plurality of angularly equidistant fixed rolling plates disposed fixedly on the machine base and disposed around the rotatable rolling plates. Each of the rotatable rolling plates and the fixed rolling plates is formed with a cutting surface that has a rolling-starting side and a rolling-ending side. Each of the feeding units is adapted to feed a row of headed nail-shaped blanks toward a standby position during rotation of the rotating shaft relative to the machine base. Each of the standby positions of the blanks is adjacent to the rolling-starting sides of the cutting surfaces of a respective one of the rotatable rolling plates and a respective one of the fixed rolling plates such that the blanks fed from a respective one of the feeding units can reach a respective one of the standby positions one by one at a time interval so as to permit movement of each of the blanks onto the rotatable rolling plates and subsequent rolling of the blanks between the rotatable rolling plates and the fixed rolling plates, thereby forming simultaneously a plurality of bolts during each thread rolling operation of the thread-rolling unit.

[0023] Preferably, the machine further includes a plurality of stop plates, which are fixed respectively to the fixed rolling plates and which are disposed respectively adjacent to the rolling-ending sides of the cutting surfaces of the fixed rolling plates so as to be adapted to contact the bolts when the bolts separate from the rolling-ending sides of the cutting surfaces of the fixed rolling plates, thereby permitting dropping of the bolts from the stop plates. A plurality of containers are disposed below the stop plates, respectively, and have open upper ends. A plurality of bolt-guiding plates have upper ends that are disposed proximately below the stop plates, respectively, and lower ends that are disposed proximately above the upper ends of the containers, so as to be adapted to permit movement of the bolts on the bolt-guiding plates, thereby guiding the bolts from the stop plates into the upper ends of the containers. Because the bolt-guiding plates are adapted to be located between the rotating shaft and the bolts when the bolts move on the bolt-guiding plates, when a person responsible for quality control accepts one of the bolts dropping from the rotatable rolling plate and the fixed rolling plate with one hand during the thread rolling operation of the machine, the bolt-guiding plates can prevent the hand of the person from coming into contact with the rotating shaft, thereby avoiding injury to the hand.

[0024] Because no guiding means is provided to guide the rotatable rolling plates, the height of the latter is not limited, thereby permitting a wider range of height change.

[0025] Furthermore, because there is no need for a high power and a linkage for driving the rotatable rolling plates, noise incurred during the thread rolling operation is reduced significantly.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] These and other features and advantages of this invention will become apparent in the following detailed description of a preferred embodiment of this inventions with reference to the accompanying drawings, in which:

[0027] FIG. 1 is a fragmentary perspective view of a reciprocating type conventional thread-rolling machine;

[0028] FIG. 2 is a schematic top view of the conventional thread-rolling machine, illustrating how a movable rolling plate is driven in order to form a bolt from a blank that is shaped as a headed nail;

[0029] FIG. 3 is a schematic side view of the preferred embodiment of a thread-rolling machine according to this invention;

[0030] FIG. 3A is a schematic view illustrating cutting surfaces of a rotatable rolling plate and a fixed rolling plate of the preferred embodiment;

[0031] FIG. 4 is a schematic top view of the preferred embodiment, illustrating how a plurality of blanks are fed in rows;

[0032] FIG. 5 is a schematic top view of the preferred embodiment, illustrating how four bolt products are moved onto four stop plates;

[0033] FIG. 6 is a schematic view of a release device of the preferred embodiment, when a blocking plate is disposed at an extended position; and

[0034] FIG. 7 is a schematic view of the release device of the preferred embodiment, when the blocking plate is disposed at a retracted position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0035] Referring to FIGS. 3, 3A and 4, the preferred embodiment of a rotating type thread-rolling machine 5 according to this invention is shown to include a machine base 51, a vertical rotating shaft 52, a thread-rolling unit consisting of four angularly equidistant rotatable rolling plates 531 and four angularly equidistant fixed rolling plates 532, a surrounding plate unit 54, and four angularly equidistant feeding units 55.

[0036] The rotating shaft 52 is journalled and rotates counterclockwise on the machine base 51. Each of the rotatable rolling plates 531 is fixed to an annular surface of the rotating shaft 52, and is formed with a cutting surface (531A) that has a rolling-starting side (531B) and a rolling-ending side (531C).

[0037] The surrounding plate unit 54 is fixed on the machine base 51, is located around the rotating shaft 52, and consists of four curved plates 541, which are arranged in a circle. Each adjacent pair of the plates 541 defines a space 542 therebetween. The fixed rolling plates 532 are fixed respectively to the inner side surfaces of the plates 541. Each of the fixed rolling plates 532 is formed with a cutting surface (532A) that has a rolling-starting side (532B) and a rolling-ending side (532C). Each of the rotatable rolling plates 531 and the fixed rolling plates 532 is formed with a plurality of inclined parallel ribs (R) (see FIG. 3A) in a known manner. Each of the fixed rolling plates 532 is provided with a V-shaped stop plate 533, which is mounted fixedly thereto so as to define a bolt-trapping space 534 therebetween.

[0038] Each of the feeding units 55 includes a funnel-shaped vibrating unit 551 for receiving and feeding a row of blanks 56 that are shaped as headed nails, and a channel member 552, which extends through a respective one of the spaces 542 in the surrounding plate unit 54. Each of the channel members 552 has a U-shaped cross-section, an inner end (552A) that is disposed adjacent to the rolling-starting sides (531B, 532B) of the cutting surfaces (531A, 532A) of a respective one of the rotatable rolling plates 531 and a respective one of the fixed rolling plates 532, an outer end (552B) that is attached to a respective one of the vibrating units 551, and two aligned walls 553 that define a slide slot 554 therebetween so as to permit sliding movement of the heads 561 of the blanks 56 on the top surf aces of the walls 553. The walls 553 have a height that reduces gradually from the outer ends (552B) to the inner ends (552A). As such, when the vibrating units 551 vibrate, the blanks 56 can slide from the vibrating units 551 toward the thread-rolling unit along the channel members 552. The inner end (552A) of each of the channel members 552 is provided with an electromagnetic release device 555, which includes an inverted U-shaped mounting member 556 that is disposed fixedly on the walls 553, and a movable blocking plate 557 (see FIG. 6) that is movable between an extended position shown in FIG. 6, where the blocking plate 557 contacts and prevents the leading one of the blanks 56 from moving on the inner end (552A) of the channel member 552, and a retracted position shown in FIG. 7, where the leading one of the blanks 56 can move from the channel member 552 to a standby position, where the head 561 of the leading blank 56 is supported on a top surface of one rotatable rolling plate 531 so as to permit the leading blank 56 to move into a space between the rotatable rolling plate 531 and one fixed rolling plate 532. The release devices 555 cooperates with the rotating shaft 52 and the rotatable rolling plates 531 under a timing control so that each releasing action of each release device 555 can release only one of the blanks 56. In addition, under the timing control, the blanks 56 always move onto the rolling-starting sides (531B) of the cutting surfaces (531A) of the rotatable rolling plates 531, and will not move into spaces between the rotatable rolling plates 531.

[0039] Subsequently, the blanks 56 roll and rotate clockwise between the rotatable rolling plates 531 and the fixed rolling plates 532, and move on the cutting surfaces (531A, 532A) from the rolling-starting sides (531B, 532B) to the rolling-ending sides (531C, 532C), thereby forming four bolts 561′ (see FIG. 5) simultaneously during each thread rolling operation of the thread-rolling unit, which consists of the rotatable rolling plates 531 and the fixed rolling plates 532. As such, the thread-rolling unit can form sixteen bolts 561′ during each revolution of the rotating shaft 52. The heads 561 of the blanks 56 are supported on the top surfaces of the rotatable rolling plates 531 and the fixed rolling plates 532 during rolling of the blanks 56 between the rotatable rolling plates 531 and the fixed rolling plates 532. Referring to FIG. 5, as soon as the bolts 561′ separate from the rolling-ending sides (532C) of the cutting surfaces (532A) of the fixed rolling plates 532, they contact the stop plates 533, thereby dropping from the bolt-trapping spaces 534.

[0040] Referring again to FIG. 3, four curved bolt-guiding plates 512 (only two are shown) are disposed fixedly on the machine base 51, and are located around the rotating shaft 52. Each bolt-guiding plate 512 has an upper end that is disposed proximately below the corresponding stop plate 533, and a lower end that is disposed proximately above an open upper end 514 of a container 513, so as to permit movement of the bolts 561′ on the bolt-guiding plate 512, thereby guiding the bolts 561′ from the stop plates 533 into the upper ends 514 of the containers 513.

[0041] When a person responsible for quality control accepts the bolts 561′ from the bolt-guiding plates 512 with one hand, because the bolt-guiding plates 512 are located between the rotating shaft 52 and the bolts 561′, they can prevent the hand from coming into contact with the rotating shaft 52, thereby preventing injury to the hand.

[0042] The rotatable rolling plates 531 may be mounted removably on the machine base 51, thereby permitting replacement of the former based on the desired length of the threaded portions of the bolt products 561′.

[0043] Furthermore, the rotating type thread-rolling machine of this invention has the advantages of simple structure, power-saving operation, and reduced noise during the thread rolling operation.

[0044] With this invention thus explained, it is apparent that numerous modifications and variations can be made without departing from the scope and spirit of this invention. It is therefore intended that this invention be limited only as indicated by the appended claims.

Claims

1. A rotating type thread-rolling machine comprising:

a machine base;

a vertical rotating shaft journalled on said machine base;

a thread-rolling unit including

a plurality of angularly equidistant rotatable rolling plates disposed fixedly on said rotating shaft, each of said rotatable rolling plates being formed with a cutting surface that has a rolling-starting side and a rolling-ending side, and

a plurality of angularly equidistant fixed rolling plates disposed fixedly on said machine base and disposed around said rotatable rolling plates, each of said fixed rolling plates being formed with a cutting surface that has a rolling-starting side and a rolling-ending side; and

a plurality of angularly equidistant feeding units disposed on said machine base, each of said feeding units being adapted to feed a row of headed nail-shaped blanks toward a standby position during rotation of said rotating shaft relative to said machine base, each of the standby positions of the blanks being adjacent to said rolling-starting sides of said cutting surfaces of a respective one of said rotatable rolling plates and a respective one of said fixed rolling plates such that the blanks fed from a respective one of said feeding units can reach a respective one of the standby positions one by one at a time interval so as to permit movement of each of the blanks onto said rotatable rolling plates and subsequent rolling of the blanks between said rotatable rolling plates and said fixed rolling plates, thereby forming simultaneously a plurality of bolts during each thread rolling operation of said thread-rolling unit.

2. The thread-rolling machine as claimed in claim 1, further comprising:

a plurality of stop plates fixed respectively to said fixed rolling plates and disposed respectively adjacent to said rolling-ending sides of said cutting surfaces of said fixed rolling plates so as to be adapted to contact the bolts when the bolts separate from said rolling-ending sides of said cutting surfaces of said fixed rolling plates, thereby permitting dropping of the bolts from said stop plates;

a plurality of containers disposed below said stop plates, respectively, and having open upper ends; and

a plurality of bolt-guiding plates having upper ends that are disposed proximately below said stop plates, respectively, and lower ends that are disposed proximately above said upper ends of said containers, so as to be adapted to permit movement of the bolts on said bolt-guiding plates, thereby guiding the bolts from said stop plates into said upper ends of said containers, said bolt-guiding plates being adapted to be located between said rotating shaft and the bolts when the bolts move on said bolt-guiding plates.

3. The thread-rolling machine as claimed in claim 2, wherein said stop plates are generally V-shaped so as to define a bolt-trapping space between a respective one of said stop plates and a respective one of said fixed rolling plates, thereby permitting movement of the bolts into said spaces when the bolts separate from said rolling-ending sides of said cutting surfaces of said fixed rolling plates.