초록 ▼

A mechanism for converting rotary motion to back and forth motion. The present mechanism is disclosed in conjunction with a jig saw having a blade mounted in a holder which is moved back and forth by a rotary eccentric. A stack of leaf springs is cantilevered on the frame of the saw and is attached

A mechanism for converting rotary motion to back and forth motion. The present mechanism is disclosed in conjunction with a jig saw having a blade mounted in a holder which is moved back and forth by a rotary eccentric. A stack of leaf springs is cantilevered on the frame of the saw and is attached rigidly to the holder to cause the blade to move in a substantially elliptical orbit.

대표청구항 ▼

1. Mechanism for converting rotary motion to back and forth motion, said mechanism comprising a support, a power driven shaft mounted on said support to rotate about a predetermined axis, a driven member operably connected to said shaft, and means for causing said driven member to move back and fort

1. Mechanism for converting rotary motion to back and forth motion, said mechanism comprising a support, a power driven shaft mounted on said support to rotate about a predetermined axis, a driven member operably connected to said shaft, and means for causing said driven member to move back and forth in response to rotation of said shaft in one direction, said means comprising a resiliently yieldable strap connected between said support and said driven member and positioned to flex resiliently in the general direction of said back and forth motion thereby to dampen vibration of said driven member, said resiliently yieldable strap comprising a stack of leaf springs disposed in face-to-face relation, each of said springs having one end cantilevered on said support and having an opposite end connected to said driven member. 2. Mechanism as defined in claim 1 in which said driven member is moved back and forth along a predetermined path, said resiliently yieldable strap being positioned so as to be stressed in one direction when said driven member is at one end of said path and to be stressed in the reverse direction when said driven member is at the other end of said path. 3. Mechanism as defined in claim 2 in which said resiliently yieldable strap is positioned so as to flex toward and away from said shaft. 4. Mechanism as defined in claim 1 in which said means further comprises an eccentric rotatable with said shaft and having an axis spaced radially from and extending parallel to the axis of the shaft whereby the axis of the eccentric moves in an orbit around the axis of the shaft when the shaft is rotated, said driven member being connected to said eccentric and being turnable relative to the shaft about the axis of the eccentric. 5. Mechanism as defined in claim 4 in which said eccentric coacts with said strap to move said driven member back and forth along a predetermined path, said strap being positioned so as to be stressed in one direction when said driven member is at one end of said path and to be stressed in the reverse direction when said driven member is at the other end of said path. 6. Mechanism for producing back and forth motion, said mechanism comprising a support, a power operated driving member on said support, a driven member, means connecting said driven member to said driving member and operable to move said driven member back and forth along a predetermined path in response to operation of said driving member, and a resiliently yieldable strap extending between and connected to said support and said driven member and positioned to flex cyclically in the general direction of said path thereby to dampen vibration of said driven member while assisting said driving member in moving said driven member, said strap being located so as to be stressed in one direction when said driven member is at one end of said path and to be stressed in the reverse direction when the driven member is at the opposite end of the path, said resiliently yieldable strap comprising a stack of leaf springs disposed in face-to-face relation, each of said springs having one end cantilevered on said support and having an opposite end connected to said driven member. 7. Mechanism as defined in claim 6 in which said driving member comprises a shaft mounted on said support to rotate about an axis coinciding with the axis of the shaft, said connecting means comprising an eccentric rotatable with said shaft and having an axis spaced radially from and extending parallel to the axis of the shaft whereby the axis of the eccentric moves in an orbit around the axis of the shaft when the shaft is rotated, said driven member being connected to said eccentric and being turnable relative to the shaft about the axis of the eccentric. 8. Mechanism for converting rotary motion to back and forth motion, said mechanism comprising a support, a power driven shaft mounted on said support to rotate about a predetermined axis coinciding with the axis of the shaft, an eccentric rotatable with said shaft and having an axis spaced radially from and extending parallel to the axis of the shaft whereby the axis of the eccentric moves in a circular orbit around the axis of the shaft when the shaft is rotated, a driven member, means connecting said driven member to said eccentric and permitting said driven member to turn relative to said shaft about the axis of the eccentric, and a resiliently yieldable strap for causing said driven member to move back and forth in response to rotation of said eccentric in one direction, said strap being connected between said support and said driven member and being flexed cyclically by said driven member in the general direction of said back and forth motion thereby to resiliently dampen vibration of said driven member, said resiliently yieldable strap comprising a stack of leaf springs disposed in face-to-face relation, each of said springs having one end cantilevered on said support and having an opposite end connected to said driven member. 9. Mechanism as defined in claim 8 in which said driven member is moved back and forth along a predetermined path, said resiliently yieldable strap being positioned so as to be stressed in one direction when said driven member is at one end of said path and to be stressed in the reverse direction when said driven member is at the other end of said path. 10. Mechanism for converting rotary motion to back and forth substantially elliptical orbital motion, said mechanism comprising a support, a power driven shaft mounted on said support to rotate about a predetermined axis coinciding with the axis of the shaft, an eccentric rotatable with said shaft and having an axis spaced radially from and extending parallel to the axis of the shaft whereby the axis of the eccentric moves in an orbit around the axis of the shaft when the shaft is rotated, a driven member, means connecting said driven member to said eccentric and permitting said driven member to turn relative to said shaft about the axis of the eccentric, said eccentric being operable to move said driven member back and forth along a path extending transversely of the axis of said shaft when said shaft is rotated in one direction, a stack of resiliently yieldable elongated leaf springs disposed in face-to-face relation and connected between said driven member and said support to cause said driven member to travel in a substantially elliptical orbit as said driven member is moved back and forth by said eccentric, each of said springs extending transversely of the axis of said shaft and extending transversely of the path of said driven member, said springs being substantially stiff edgewise and being capable of flexing resiliently back and forth in the general direction of said path, and said springs being located so as to be stressed in one direction when said driven member is at one end of said path and to be stressed in the reverse direction when the driven member is at the other end of said path.