US3910590A

US3910590A - Tool retainer

Info

Publication number: US3910590A
Application number: US482238A
Authority: US
Inventors: Gosta Ivar Ekstrom
Original assignee: Atlas Copco AB
Current assignee: Atlas Copco AB
Priority date: 1973-07-11
Filing date: 1974-06-24
Publication date: 1975-10-07
Anticipated expiration: 1992-10-07
Also published as: SE405328B; CA1001396A; GB1382019A; FR2237426A7; SE7408156L

Abstract

A tool retainer adapted for impacting machines and comprising a latch mounted in a sleeve of resilient material. The latch is releasably locked in a tool securing position by resilient snap action.

Description

United States Patent Ekstriim Oct. 7, 1975 1 TOOL RETAINER [75] Inventor: Giista Ivar Ekstriim, Nacka, Sweden [56] References Cited [73] Assignee: Atlas Copco Aktiebolag, Nacka, UNITED STTES PATENTS Sweden 1,176,343 3/1916 Chnstiansen 279/191 2,298,719 10/1942 OFarrell 279/195 [22] Filed: June 24, 1974 3,525,531 8/1970 Ekstrom et a1. 279/196 1 1. .1 4 2, l [2 1 App NO 8 238 Primary Examiner-G11 We1denfeld Attorney, Agent, or Firm-Flynn & Frishauf [30] Foreign Application Priority Data July 11, 1973 United Kingdom 33159/73 [57] ABSTRACT A tool retainer adapted for impacting machines and [52] 279/l9'l; 279/1 403/300 comprising a latch mounted in a s1eeve of resilient ma- I t C 2 1 3632 terial. The latch is releasably locked in a tool securing n b t 58 Field of Search 279/191, 19.6, 19, 19.2, y Snap ac 279/19.5,1 Q, 77, 78; 403/300, 305, 12 Clalms, 5 a g Figures 3 L Z I II III US. Patent Oct. 7,1975 Sheet 2 of2 3,910,590

TOOL RETAINER This invention relates to a tool retainer, particularly for use with hand-held impacting machines.

SUMMARY OF THE INVENTION According to the invention, there is provided a tool retainer for retaining a tool having a shank with a collar thereon, comprising a sleeve of resilient material, a latch for retaining the tool mounted in the sleeve, the latch having a working surface for abutting the collar of the tool to retain the tool, the latch being movable between an active position where it projects into the axial passage through the sleeve to retain the tool and an inactive position where it is substantially withdrawn from said axial passage to allow withdrawal of the tool, and locking means for locking the latch in the active position by snappingit past a portion of the sleeve.

It is an advantage of this invention that the tool retainer can be made from a small number of parts, and that insertion of the tool and subsequent locking of the latch is a very simple operation.

Preferably, the latch is pivotable about a latch pin mounted in part of the resilient sleeve, so that impacts of the tool collar on the working surface of the latch are at least partly absorbed by the resilient latch mounting.

Preferably, the locking means is provided by a space between two resilient lugs, the space having a wider portion of similar or larger cross-section than a handle of the latch and a narrower portion through which the handle can only pass when the lugs are resiliently displaced relative to each other.

Preferably, the sleeve, locking means and latch pin mounting are all formed from one piece of resilient material.

Preferably, the sleeve rear end portion is secured around a relatively non-resilient tool holder in which the rear end portion of the tool can slide.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be further described, by way ings, in which:

FIG. 1 is a section through the end of an impacting machine incorporating a tool retainer in accordance with the invention;

FIG. 2 is a section on the line II-II of FIG. 1;

FIG. 3 is a section on the line III-III of FIG. 1;

FIG. 4 is a section through a second embodiment of an impacting machine incorporating a tool retainer;

FIG. 5 is a section on the line VV of FIG. 4.

DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS A sleeve 1 of resilient material is fitted tightly around a tool holder 2 forming part of the housing of an impacting machine such as a concrete breaker, a rock drill or the like. At its other end, the sleeve, has an axial passage 3 of larger diameter than the diameter of a collar 4 of a tool shank 5. The sleeve 1 may all be molded as a single piece, and can be a snap fit on the tool holder 2. When it is necessary to separate the two parts,

, a special tool must be used. The tool shank 5 has a suitably shaped, preferably hexagonal portion 6 which is a sliding fit in the tool holder 2.

Referring now to FIG. l-3, a latch 7 with a handle 8 is journalled on a pivot pin 9, the pivot pin being of example, with reference to the accompanying drawmounted in lugs 10 made of resilient material with resilient retaining shoulders 17. The latch 7 has a working surface 11 arranged at right angles to the direction of movement of the tool, and the sleeve 1 has a recess 12 with an abutment surface 16 for the surface 11 to receive the working surface 11 when the latch is opened to allow the tool to be inserted or removed.

The resilient material referred to above may for instance be a plastic material such as caprolactan, polyether urethane, or other materials of the polyeth'er or polyester type.

FIG. 2 shows how the handle 8 is held in the locking means to retain the working surface 11 in the working position. To secure the handle 8,

lugs

13,14 must be pushed apart sufficiently to allow the handle 8 to pass between them, after which they snap back into position, and the handle 8 is secured. The handle 8 can conveniently be operated by the operators foot, and the rigidity of the

lugs

13,14 is designed in accordance with this.

To insert a tool into the impacting machine, the latch 7 is pivoted so that the surface 11 is accommodated in the recess 12. The hexagonal portion 6 of the tool can then be pushed into the tool holder 2, and the collar 4 will be able to pass the latch 7. When the tool is in position, the latch 7 is again pivoted so that the surface 11 projects into the passage 3 and abuts against the collar 4 if the tool moves in the direction of the arrow 15.

A second embodiment of a tool retainer is shown in FIG. 4. In this Figure, similar parts to those shown in FIG. 1 are given the same reference numerals.

In this embodiment, the latch 20 is movable along its own axis between active and inactive positions. The latch 20 has a working surface 21 shaped to fit with the collar 4 of the tool, and a projection 22 for helping to move the latch 20 along its axis. A resilient stop arrangement is indicated at 23. When the narrow or necked down portion of the latch 20 is held by the stop arrangement 23, the surface 21 is in its active position, and will prevent removal of the tool from the sleeve 1.

To move the latch into the inactive position, the projection 22 is pushed away from the sleeve 1 This can be done with the .foot. The stop arrangement 23 disengages and the working surface 21 moves out of the passage 3'. A secondary stop arrangement is shown at 24,25,26 which prevents the latch 20 from falling completely out of the sleeve, and from falling back into the active postion.

As shown at 18 in FIG. 1, lugs are provided on the end of the sleeve 1 which cooperate with correspond ing metal lugs projecting from the tool holder 2. This configuration prevents rotation of the sleeve 1 on the tool holder 2, and also allows the orientation of the latch with respect to the impact machine to be altered, for instance to suit a rightor left-handed operator.

FIG. 5 shows an alternative arrangement for achiev-' ing the same object. Here the tool holder 2 can be placed in four different angular positions relative the sleeve 1.

In operation, the tool is hit at the rear end of the hexagonal portion 6 and the impact thus received is transmitted in the direction shown by the arrow 15 to the working surface against which the tool is urged by the machine operator. Normally, the collar 4 does not hit against the surfaces 11 (FIG. 1) or 21 (FIG. 4) on the outward stroke. However, if the tool runs into a soft patch in the working surface, or if there is no surface for it to work against, then the collar 4 will hit the surface 11 (or 21). If and when the collar 4 reaches the surface 11 (or 21), the tool is stopped and the energy is absorbed partly by the resilient sleeve 1, which may stretch a little along the direction 15 and partly in the FIG. 1 embodiment by the resilient pivot pin lugs which may allow the latch to move a small distance relative to the sleeve 1.

An advantage gained by the use of a resilient sleeve is that the metal latch member can be made of a much harder and more wear-resistant material than was hitherto possible. The shock produced by impacts of the tool collar on the latch is absorbed by the resilient material and there is thus a considerably reduced tendency to crack the latch. The latch may, for instance, be case-hardened. This makes the metal more suscepti ble to cracking, but this is not so important with a resilient sleeve.

A resilient sleeve also makes operation of the impacting machine less noisy, and contributes towards a lower overall weight of the machine.

What I claim is:

l. A tool retainer for retaining a tool having a shank with a collar thereon, comprising:

a sleeve of resilient material having an axial passage therethrough for receiving said tool therein,

a latch movably mounted in the sleeve for retaining the tool in the sleeve, the latch having a working surface for abutting the collar of the tool to retain the tool, the latch being movable between an active position where it projects into the axial passage throughthe sleeve to retain the tool and an inactive position where it is substantially withdrawn from said axial passage to allow withdrawal of the tool, and

locking means including a resilient sleeve portion normally projecting in the path of movement of said latch for lockingly engaging said latch in the active position by moving said latch past said projecting sleeve portion, said projecting sleeve portion snapping substantially back to its normal projecting position after passage of said latch, thereby locking said latch in said active position.

2. A tool retainer for retaining a tool having a shank with a collar thereon, comprising:

a latch pivotally mounted to the sleeve for retaining the tool in the sleeve, the pivotable latch having a working surface movable upon pivoting of said latch to a working position for abutting the collar of the tool to retain the tool, the latch being pivotable to move the working surface towards and away from the axial passage through the sleeve, and

locking means including a resilient sleeve portion normally projecting in the path of movement of said latch for lockingly engaging said latch in the working position by moving said latch past said projecting sleeve portion, said projecting sleeve portion snapping substantially back to its normally projecting position after passage of said latch, thereby locking said latch in said working position.

3. A tool retainer as claimed in claim 2 comprising a latch pin mounted in part of the resilient sleeve and about which said latch is pivotally mounted, so that impacts of the tool collar on the working surface of the latch are, at least partly, absorbed by the resilient latch mounting.

4. A tool retainer as claimed in claim 2 wherein said latch has a handle, and wherein the locking means comprises two resilient lugs having a space therebetween, the space having a wider portion of similar or larger cross-section than the handle of the latch, and a narrower portion through which the handle can only pass when the lugs are resiliently displaced relative to each other.

5. A tool retainer as claimed in claim 3, wherein the sleeve, locking means, and latch pin mounting are all formed from one piece of resilient material.

6. A tool retainer as claimed in claim 2, wherein the end portion of the sleeve which is more distant from the latch includes means for receiving a relatively nonresilient tool holder in which the rear end portion of the tool can slide.

7. A tool retainer as claimed in claim 1 wherein the latch is movable along its own axis.

8. A tool retainer as claimed in claim 3 wherein said latch has a handle, and wherein the locking means comprises two resilient lugs having a space therebetween, the space having a wider portion of similar or larger cross-section than the handle of the latch, and a narrower portion through which the handle can only pass when the lugs are resiliently displaced relative to each other.

9. A tool retainer as claimed in claim 4, wherein the sleeve, locking means and latch pin mounting are all formed from one piece of resilient material.

10. A tool retainer as claimed in claim 2 wherein said sleeve of resilient material has an opening therethrough to permit said working surface of said pivotable latch to pass through said opening into said axial passage.

11. A tool retainer as claimed in claim 7 wherein said sleeve of resilient material has a further passage therethrough, said further-passage extending at an angle relative to said axial passage, said latch being slideably engaged in said further passage and being movable along said further passage between said active and inactive position.

12. A tool retainer as claimed in claim 11 wherein said locking means comprises a first locking means for locking said latch in said active position and a second locking means for locking said latch in said inactive position.

Claims

1. A tool retainer for retaining a tool having a shank with a collar thereon, comprising: a sleeve of resilient material having an axial passage therethrough for receiving said tool therein, a latch movably mounted in the sleeve for retaining the tool in the sleeve, the latch having a working surface for abutting the collar of the tool to retain the tool, the latch being movable between an active position where it projects into the axial passage through the sleeve to retain the tool and an inactive position where it is substantially withdrawn from said axial passage to allow withdrawal of the tool, and locking means including a resilient sleeve portion normally projecting in the path of movement of said latch for lockingly engaging said latch in the active position by moving said latch past said projecting sleeve portion, said projecting sleeve portion snapping substantially back to its normal projecting position after passage of said latch, thereby locking said latch in said active position.

2. A tool retainer for retaining a tool having a shank with a collar thereon, comprising: a sleeve of resilient material having an axial passage therethrough for receiving said tool therein, a latch pivotally mounted to the sleeve for retaining the tool in the sleeve, the pivotable latch having a working surface movable upon pivoting of said latch to a working position for abutting the collar of the tool to retain the tool, the latch being pivotable to move the working surface towards and away from the axial passage through the sleeve, and locking means including a resilient sleeve portion normally projecting in the path of movement of said latch for lockingly engaging said latch in the working position by moving said latch past said projecting sleeve portion, said projecting sleeve portion snapping substantially back to its normally projecting position after passage of said latch, thereby locking said latch in said working position.

11. A tool retainer as claimed in claim 7 wherein said sleeve of resilient material has a further passage therethrough, said further passage extending at an angle relative to said axial passage, said latch being slideably engaged in said further passage and being movable along said further passage between said active and inactive position.