Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23B—TURNING; BORING
  • B23B31/00—Chucks; Expansion mandrels; Adaptations thereof for remote control
  • B23B31/02—Chucks
  • B23B31/10—Chucks characterised by the retaining or gripping devices or their immediate operating means
  • B23B31/12—Chucks with simultaneously-acting jaws, whether or not also individually adjustable
  • B23B31/1207—Chucks with simultaneously-acting jaws, whether or not also individually adjustable moving obliquely to the axis of the chuck in a plane containing this axis
  • B23B31/1238—Jaws movement actuated by a nut with conical screw-thread
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23B—TURNING; BORING
  • B23B2231/00—Details of chucks, toolholder shanks or tool shanks
  • B23B2231/38—Keyless chucks for hand tools
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23B—TURNING; BORING
  • B23B2231/00—Details of chucks, toolholder shanks or tool shanks
  • B23B2231/44—Nose pieces

Definitions

• This invention relates to a tool chuck which grips tools such as the drill bit of an electric drill or the driver bit of an electric screwdriver.
• Prior Art There are various examples in prior art of tool chucks which can be powerfully clamped using the grip of a hand and without using a chuck handle (for example, Japanese Patent Application Nos. 2- 80395 and 2-213245) , but if these are exposed to continuous strong vibration during work, the grip of the chuck is frequently loosened.
• This invention has the purpose of providing a tool chuck which in addition to being able to clamp powerfully using the grip of a hand only, does not loosen its grips with a vibrating load.
• This invention is characterized in being a tool chuck which in addition to being a tool chuck provided at the center of the chuck body with a plurality of chuck jaws set obliquely and able to slide open and shut, has a partial male thread engraved around the outside of said chuck jaws, and is provided with a nut ring which screws onto this partial male thread and which screw feeds said chuck jaws in the direction of opening and closing, the rotational force of an operating ring fitted onto said chuck body being transmitted to said nut ring, each chuck jaw sliding in the direction of opening and closing, the tool being gripped by the closing of said chuck jaws, an input ring being fitted into and fixed to the inner surface of said operating ring facing the nut ring, a thrust ring being fitted between the inner side of said input ring and the chuck body which positions a ball holder on the chuck body side, a ball thread being formed between the inner face of said input ring and the outer face of the nut
• the rolling movement of the balls in said ball thread involves rolling of the balls, so with screw feed of the nut ring carried out with balls rotated with a 1/2 rotation of the input ring, since the balls roll around there is no loss in the rotation input from the input ring (the efficiency of rotation transmission is good) and a great increase in torque can be obtained.
• the above effect means that the tool can be powerfully clamped without using a chuck handle due to the enhanced power of the nut ring.
• this enhanced power allows a strong torque to be obtained since the thread angle of the ball threads is small and the ratio of the amount of nut ring screw feed to the amount of rotation of the input ring is large.
• power is enhanced by the efficient transmission of rotation and absence of rotational loss due to the rolling of the balls in the ball thread, thus creating a powerfully enhanced grip.
• Figure 1 is a cross section of tool chuck
• Figure 2 is an exploded cross section of tool chuc ;
• Figure 3 is a cross section seen through line A-A in Figure 1;
• Figure 4 is a developmental diagram of retainer;
• Figure 5 is a rear view of locking ring; and Figure 6 is a cross section seen through line B-B in Figure 5.
• a tool chuck which grips the drill bit of an electric drill or the driver bit of an electric screwdriver or the like, and moreover show a tool chuck which can be clamped without using a chuck handle.
• tool chuck 10 is provided with three chuck jaws 12 at the center of the tip of chuck body 11, these being provided in an oblique shape which come together at the tip with respect to the shaft of chuck body 10 and moreover are able to slide open and shut.
• said three chuck jaws 12 are inserted so as to only slide freely within slide grooves 13 formed respectively in an oblique shape with respect to the axis of chuck body 11.
• On the outside of the inner end of said chuck jaws 12 are engraved partial male threads 14 in such a way that they are respectively continuous, these partial male threads 14 engaging with a female thread 16 engraved on the inner surface of the conical part of a cylindrical nut ring 15, said nut ring 15 being supported so as to rotate around the outer surface of chuck body 11, and by applying a forward and reverse rotation to this nut ring 15, chuck jaws 12 are slid open and shut by screw feed, thus enabling the tool to be gripped or released.
• thrust bearing 22 which positions ball holder 21 on the side of chuck body 11.
• the outer diameter of ball holder 21 is fixed at a gauge which allows rotation relative to operating ring 17.
• a locking ring 40 for operating ring 17 is fitted between ball holder 21 and chuck body 11.
• ball thread 23 which screw feeds in the direction of the forward thrust of nut ring 15 with rotation of input ring 18 in the direction of clamping.
• This ball thread 23 is comprised of thread grooves 24 formed on the inside surface of input ring 18, thread grooves 25 formed on the outer surface of nut ring 15, and balls 27 housed within said thread grooves 24, 25 and retained so as to be able to rotate in retainer 26.
• Balls 27, as shown in Figure 4, are distributed in a zigzag pattern between adjacent screw lines, and formed so that a number of balls 27 can be retained with the screw pitch kept small, and moreover the thread angle ⁇ of the screw lines is made small, it being made smaller than the thread angle of female thread 16 of nut ring 15.
• On the inner periphery of said nut ring 15 are formed latch claws 28 of uneven shape in the axial direction, and moreover on the inner surface of ball holder 21 are formed latch claws 29 corresponding to these of uneven shape in a longitudinal direction which engage with said latch claws 28, and when ball holder 21 is fixed, it is possible to lock the rotation of nut ring 15 through the engagement of these latch claws 28, 29.
• Said locking ring 40 is provided with four elastic members 32 on the outer surface of ring base 31, heads 33 being formed on their free ends, with heads 33 engaging elastically with concave grooves 19 formed on the inner surface of said operating ring 17, and when this locking ring 40 is fixed integrally to chuck body 11 it braces the position of operating ring 17 elastically, and prevents it from loosening.
• Friction surfaces 34 with an irregular surface are formed on the inside and outside of said ring base 31, the frictional resistance with corresponding parts in contact with these being great and giving a locking effect.
• friction surfaces are formed on the surfaces in contact with ring base 31 of said ball holder 21.
• 35 is a retainer ring which is pressed into chuck body 11 and acts as a retainer for the attached parts
• 36 is a protector ring for return spring 30 which is pressed into chuck body 11
• 37 is a rear cover for chuck body 11.
• Nut ring 15 is formed as an integral ring, but even if the conventional two part ring is used, since it can beheld in one piece by the structure of ball thread 23, it is also possible to use this two-part nut ring.
• a tool is inserted with chuck jaws 12 withdrawn inside, and operating ring 17 is manually rotated in the direction of gripping.
• the rolling movement of balls 27 in ball thread 23 involves rolling of balls 27, so with screw feed of the ring 15 carried out with balls 27 rotated with a 1/2 rotation of input ring 18, since balls 27 roll around there is no loss in the rotation input from input ring 18 (the efficiency of rotation transmission is good) and a great increase in torque can be obtained.
• nut ring 15 enters a state where its rotation is locked, and thus even if vibration is applied to tool chuck 10, and even if applied continuously, nut ring 15 will not rotate and loosen its grip due to this rotation, thus enabling a powerful clamping state to be maintained.
• locking ring 40 is braced against operating ring 17, operating ring 17 will also not loosen with vibration.
• Nut ring 15 may be constructed so that the front end of its inner diameter and the screw head of female thread 16 is directly supported by the outer diameter of chuck body 11, and moreover, although thrust bearing 22 combines the outer retainer in the inner edge of input ring 18, this structure may be formed such that there is a separate and independent thrust bearing 22.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Gripping On Spindles (AREA)

Applications Claiming Priority (3)

Publications (2)

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Family Applications (1)

Country Status (3)

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• 1997
  • 1997-01-06 AU AU17453/97A patent/AU1745397A/en not_active Abandoned
  • 1997-01-06 EP EP97904736A patent/EP0876236A4/de not_active Withdrawn
  • 1997-01-06 WO PCT/US1997/000227 patent/WO1997027020A1/en not_active Application Discontinuation

Non-Patent Citations (2)

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