Spool feed mechanism for line fed grass trimmer

• US 4,285,128 A
• Filed: 11/16/1979
• Issued: 08/25/1981
• Est. Priority Date: 11/16/1979
• Status: Expired due to Term

• Current Assignee: Benchmark Tool Company
• Original Assignee: Benchmark Tool Company
• Inventors: Schnell, John W., Haenel, Max K.
• Primary Examiner(s): Peters, Jimmy C.
• Application Number:
  US06/095,604
• Time in Patent Office: 648 Days
• Field of Search: 30/276, 30/347, 56/12.7, 56/295
• US Class Current: 30/276
• CPC Class Codes: A01D 34/4161 Means for feeding cutter line

Abstract

A spool feed mechanism for a non-metallic, line grass trimmer wherein the free end of the cutting line is spun at high speed for cutting vegetation, includes a spool of cutting line mounted for rotation about the central axis thereof. The spool has first and second ratchet wheels located at respective ends. Each ratchet wheel includes a set of ratchet teeth, one set of which is angularly displaced with respect to the other. A U-shaped, resilient member having first and second pawls provided on the legs thereof is mounted adjacent the spool with the pawls positioned for alternate engagement and disengagement of the respective ratchet wheels. A manually operated trigger assembly coupled to the member moves the latter from a normal position to disengage the first pawl and ratchet wheel and to engage the second pawl and ratchet wheel, whereby the spool is permitted to rotate incrementally to feed a predetermined length of cutting line. Movement of the member back to the normal position feeds out a second predetermined length of line. A force applied at the center of the resilient member disengages both pawls and respective ratchet wheels to permit free rotation of the spool to load a fresh spool of cutting line.

Claims

1. In apparatus for cutting vegetation with the free end of a flexible, non-metallic line played out from a spool, including a rotatably driven cutting head for spinning the free end of the line, a spool feed mechanism mounted on said apparatus for incrementally feeding a predetermined length of line from said spool, said mechanism including in combination;

a spool about which said flexible cutting line is wound, said spool being mounted for rotation about the central axis thereof at a position remote from said rotatably driven cutting head and including first and second ends with first and second spool indexing means, respectively, actuating means including first and second engagement means positioned for cooperative engagement with said first and second spool indexing means, respectively, one of said spool and actuating means being mounted for movement relative to the other for alternate engagement of said first spool indexing means and said first engagement means and said second spool indexing means and said second engagement means, respectively, one of said first and second engagement means and said first and second indexing means being displaced with respect to the other of said first and second engagement means and the other of said first and second indexing means, respectively, to provide successive incremental rotation of said spool in response to the alternate engagement of said corresponding engagement means and indexing means whereby successive predetermined lengths of cutting line are fed from said spool, and means for biasing one of said spool and actuating means to a first position whereby said first engagement means and first indexing means are normally engaged.

2. Vegetation cutting apparatus as claimed in claim 1 wherein said first and second indexing means include first and second ratchet wheels, respectively, each having a set of radially extending, circumferentially spaced teeth and wherein said first and second engagement means include first and second pawls, respectively.

3. Vegetation cutting apparatus as claimed in claim 2 wherein said set of teeth of said first ratchet wheel of said spool are displaced angularly about the axis of rotation of said spool from said set of teeth of said second ratchet wheel and wherein said first and second pawls are aligned with respect to the axis of rotation of said spool for engagement of respective ones of said sets of teeth of said ratchet wheels.

4. In apparatus for cutting vegetation with the free end of a flexible, non-metallic line played out from a spool, including a rotatably driven cutting head for spinning the free end of the line, a spool feed mechanism mounted on said apparatus for incrementally feeding a predetermined length of line from said spool, said mechanism comprising:

a spool about which said flexible cutting line is wound, said spool being mounted for rotation about the central axis thereof and including first and second ends with first and second ratchet wheels, respectively, each having a set of radially extending, circumferentially spaced teeth;

actuating means including

first and second pawls positioned for cooperative engagement with said first and second ratchet wheels, respectively, one of said ratchet wheels and pawls being mounted for movement relative to the other for alternative engagement of said first ratchet wheel and said first pawl and said second ratchet wheel and said second pawl, respectively, one of said first and second pawls and said first and second ratchet wheels being displaced with respect to the other of said first and second pawls and the other of said first and second ratchet wheels, respectively, to provide successive incremental rotation of said spool in response to the alternate engagement of said corresponding pawls and ratchet wheels whereby successive predetermined lengths of cutting line are fed from said spool,

a resilient, generally U-shaped member, each of the legs of the U including one of said first and second pawls, respectively, said resilient member being mounted with the bight thereof in parallel alignment with the axis of rotation of said spool, said pawls being positioned for engagement with respective ones of said ratchet wheels, and further including manually operated trigger means engageable with the bight of said member for bending said member and simultaneously disengaging both said pawls from respective ones of said ratchet wheels, whereby said spool is permitted to rotate freely; and

means for biasing one of said ratchet wheels and pawls to a first position whereby said first pawl and first ratchet wheel are normally engaged.

5. Vegetation cutting apparatus as claimed in claim 4 wherein said manually operated trigger means is coupled to said U-shaped member, wherein movement of said manually operated trigger means in a first direction disengages said first pawl and ratchet wheel and engages said second pawl and ratchet wheel, thereby permitting said spool to be rotated a first incremental amount, said biasing means returning said member and said manually operated trigger means to re-engage said first pawl and ratchet wheel and to disengage said second pawl and ratchet wheel, whereby said spool is permitted to be rotated a second incremental amount.

6. Apparatus for cutting vegetation with the free end of a flexible, non-metallic line played out from the spool, including in combination:

a cutting head including rotatably mounted means for spinning the free end of said line;

a handle including means operably coupled to said cutting head for controlling the rotation of said rotatably mounted means;

an elongated, hollow support shaft joining said cutting head and said handle, said shaft defining an aperture providing communication with the interior of said shaft; and

a spool feed mechanism for feeding flexible cutting through said shaft to said cutting head, said spool feed mechanism comprising a housing mounted on said support shaft near said handle, said housing defining a compartment therein located adjacent said aperture in said hollow support shaft, a spool about which said cutting line is wound, mounted in said compartment for rotation about the central axis thereof to feed cutting line from said spool into said aperture, through said support shaft to said cutting head, said spool having first and second ends including first and second spool indexing means, respectively, actuating means including first and second engagement means, mounted in said housing for cooperative engagement with said first and second spool indexing means, said actuating means being mounted for movement relative to said spool between first and second positions for alternate engagement of said first spool indexing means and said first engagement means and said second spool indexing means and second engagement means, respectively, whereby successive, predetermined, incremental rotation of said spool is permitted, thereby to feed successive predetermined lengths of cutting line to said cutting head, resilient biasing means coupled to said actuating means for biasing said actuating means to said first postion and manually operated trigger means coupled to said actuating means for moving said actuating means from said first to said second position.

7. Vegetation cutting apparatus as claimed in claim 6 wherein said first and second indexing means include first and second ratchet wheels, respectively, each said wheel having a set of radially extending, circumferentially spaced teeth, wherein said actuating means includes a resilient, u-shaped member, wherein said first and second engagement means include first and second pawls respectively, extending from opposite legs of said u-shaped member and wherein said manually operated trigger means is mounted for engagement of the bight portion of said resilient u-shaped member upon moving said manually operated trigger means in a predetermined direction, whereby said first and second pawls are both disengaged from respective ratchet wheels to permit said spool to rotate freely.

8. Vegetation cutting apparatus as claimed in claim 7 wherein said set of teeth of said first ratchet wheel is displaced angularly about the axis of rotation of said spool from said set of teeth of said second ratchet wheel and wherein said first and second pawls are aligned with respect to the axis of rotation of said spool for alternate engagement of said sets of teeth of said respective ratchet wheels.

9. Vegetation cutting apparatus as claimed in claim 8 wherein said u-shaped member is mounted adjacent said spool with the bight of said member in generally parallel alignment with the axis of rotation of said spool and wherein said u-shaped member is moveable in a direction parallel to the axis of rotation of said spool for alternate engagement and disengagement of said pawls and ratchet wheels, respectively.

10. Vegetation cutting apparatus as claimed in claim 7 further including spaced support members disposed adjacent said spool and wherein said u-shaped member is mounted on said support members with the bight of said u-shaped member positioned in slidable engagement therewith for alternate engagement and disengagement of said pawls and ratchet wheels, respectively said u-shaped member being bendable on said support members in response to the movement of said manually operated trigger means in said predetermined direction for disengagement of both said pawls and respective ratchet wheels.