JAW ASSEMBLY

Abstract

The present disclosure provides a jaw assembly for mounting to a lathe spindle. The jaw assembly comprises a first jaw set with at least one axially extending jaw portion which comprises a channel extending in the same axial direction as the jaw portion, and a second jaw set locatable within and releasably attached to the first jaw set via at least one fastener locatable in the channel.

Claims

1. A jaw assembly for mounting to a lathe spindle, comprising; a first jaw set comprising at least one axially extending jaw portion, wherein the at least one jaw portion comprises a channel that extends in the same axial direction as the jaw portion, a second jaw set, wherein the second jaw set is locatable within and releasably attached to the first jaw set via at least one fastener locatable in the channel.

2. The jaw assembly according to claim 1, comprising a first condition where the first jaw set is arranged to be mounted to a lathe chuck.

3. The jaw assembly according to claim 2, wherein the at least one jaw portion of the first jaw set is suitable for clamping a workpiece to be machined in the first condition.

4. The jaw assembly according to claim 2, comprising a second condition wherein the second jaw set is suitable for clamping a material to be machined, whilst being mounted to the first jaw set.

5. The jaw assembly according to claim 1, wherein the channel comprises an open-end suitable for receiving the fastener.

6. The jaw assembly according to claim 1, wherein the channel comprises a recess suitable for receiving a portion of the fastener.

7. The jaw assembly according to claim 6, wherein the recess is tapered.

8. The jaw assembly according to claim 6, wherein a depth of the channel is reduced in the recess with respect to a remainder of the channel.

9. The jaw assembly according to claim 5, wherein the fastener comprises a stem that is suitable for locating through the open-end of the channel of the first jaw set.

10. The jaw assembly according to claim 6, wherein the fastener comprises a bolt and bolt-head, wherein the bolt-head is suitable for being received in the recess of the channel.

11. The jaw assembly according to claim 9, wherein the bolt-head is tapered.

12. The jaw assembly according to claim 1, wherein the fastener comprises a captive fastener that remains held on the second jaw set when released from the first jaw set.

13. The jaw assembly according to claim 12, wherein the fastener comprises a cap that is configured to hold the fastener captive with the second jaw set.

14. The jaw assembly according to claim 1, wherein the first jaw set comprises a plurality of first jaw members, each comprising an axially extending jaw portion and channel, preferably four first jaw members.

15. The jaw assembly according to claim 14, wherein the second jaw set comprises a plurality of second jaw members, preferably four second jaw members.

16. The jaw assembly according to claim 15, wherein each of the first jaw members are releasably attached to a second jaw member via a respective fastener in its channel.

17. The jaw assembly according to claim 16, wherein the second jaw members each comprise an aperture, and where the fastener is threadedly engaged into the aperture.

18. A jaw assembly according to claim 1, where the at least one jaw portion of the first jaw set comprises a ledge, and the second jaw set comprises at least one engagement surface, wherein the ledge and engagement surface engage when clamping a workpiece to be machined.

19. A jaw assembly according to claim 1, comprising a plurality of second jaw sets, wherein the plurality of second jaw sets are interchangeable such that any one of the second jaw sets may be releasably attached and coaxially locatable within the first jaw set via a respective fastener, and wherein the plurality of second jaw sets each comprise a unique jaw portion such as to provide a specific jaw profile for clamping workpieces to be machined.

20. A method of using a jaw assembly according to claim 1, comprising the steps of, mounting the first jaw set to a lathe chuck, locating a second jaw set with a captive fastener coaxially within the first jaw set, such that the fastener locates into the channel, and fastening the fastener such that the first and second jaw sets are locked together.

Description

[0088] Workable embodiments of the invention are described in further detail below, by way of example only, with reference to the accompanying drawings, of which:

[0089] FIG. 1 shows a 3D view of a first jaw set.

[0090] FIG. 2 shows a side-view of a first jaw set.

[0091] FIG. 3 shows a 3D view of a second jaw set.

[0092] FIG. 4 shows an exploded 3d view of a fastener.

[0093] FIG. 5 shows a 3D view of an assembly comprising a kit of parts.

[0094] FIG. 6 shows a schematic view of a lathe showing the location of the jaw assembly.

DETAILED DESCRIPTION OF FIGURES

[0095] FIGS. 1-5 show a jaw assembly comprising a first jaw set, a second jaw set and a fastener according to a preferred embodiment of the invention.

[0096] The first jaw set 10 is shown in FIG. 1 in isolation. The first jaw set 10 is suitable for being mounted to a chuck lathe and is comprised of four first jaw members 11. Each of the first jaw members 11 are identical in size & shape and thus the first jaw set will be described by reference to one of the first jaw members 11.

[0097] Each first jaw member 11 comprises a back plate 12 which is suitable for being mounted to a lathe chuck. First 13 and second 14 mounting apertures are located in the back plate and are suitable for receiving an engagement member, such as a bolt, to mount onto a chuck. However, other forms of engagement between the chuck and first jaw members are envisioned (e.g. screws, clips, bayonets etc)

[0098] A jaw portion 15 extends axially from the back plate between the first 13 and second 14 mounting apertures and is arched in shape, such that the collection of jaw portions 15 is suitable for clamping an item. The jaw portion further comprises a ledge 19 that protrudes radially inwardly and is proximal to the open-end 17 of the channel 16.

[0099] Best shown in FIG. 2, the jaw portion 15 further comprises a channel 16 that extends from an open-end 17 to a tapered recess 18. The depth of the channel 16 varies along the length and is lower in the recess with respect to the open-end 17.

[0100] The back plate 12 comprises a circular rib 21 and grooves (not shown) that engage with complementary profiles on the chuck.

[0101] FIG. 3 shows a second jaw set 30 comprised of four second jaw members 31. Each second jaw member 31 comprises a base 32 and jaw portion 33 extending therefrom. A threaded aperture 34 is located in the side wall of the base portion 32. The upper rim of the base portion 32 forms an engagement surface 37 that is complementary shaped to the ledge 19 of the first jaw set 10. The inner surface 35 of the jaw portion 33 is suitable to clamp around the periphery an object.

[0102] A fastener 40 is shown in FIG. 4 and comprises a bolt 41 and cap 42. The bolt 41 has a bolt-head 43 and stem portion 44. A recess 45 can be seen at the bottom end of the stem 44, opposite the bolt-head 43 end. The cap 42 comprises a cap member 46 and washer 47 and locates into the recess in the bolt stem portion 44. The cap member 46 comprises a screw portion 48 that is threadedly engaged to the stem recess 45. Similarly at least a portion of the outer surface of the stem is threaded (threads not shown in figures). The bolt-head 43 is tapered in shape.

[0103] FIG. 5 shows a jaw assembly. The second jaw members 31 are located coaxially within the first jaw set 10. Each first jaw member 11 is engaged to a second jaw member 31 via a fastener 40. The engagement surface 37 of the second jaw member 31 complements the shape of the ledge 19 of the first jaw member 31.

[0104] The fastener 40 is threaded to the aperture 34 located on the side wall of the second jaw member 31 and fastened, such as to attach the first 11 and second 31 jaw members. The tapered angle of the bolt-head 43 complements the shape of the recess 18. The bolt-head 43 has a recess 49 for receiving a key to fasten the parts together. The cap 42 prevents the fastener 40 from being disengaged completely from the second jaw member 31.

Operation

[0105] The jaw assembly defines two operational conditions for use in a lathe.

[0106] The first condition is substantially shown in FIG. 1 and comprises the first jaw set 10 only. In this condition, each of the first jaw members 11 are mounted to the slider-jaws of a chuck (not shown) via bolts in the first 13 and second 14 mounting apertures. The rib 21 and grooves on the back plate 12 engage with complementary shaped portions of the chuck. Once mounted, an item such as cylindrical wood stock may be inserted within the axially extending jaw portions and clamped by adjusting the slider-jaws on the chuck.

[0107] The second condition is shown in FIG. 5, with the first 10 and second 30 jaw sets attached together via the fastener 40. The stem portion 44 of each fastener 40 is threaded to the aperture 34 of the second jaw members 31. The cap 42 is then screwed into the recess 45 of the stem 44 preventing disengagement of the second jaw member 31 and cap 42. A substantial portion of the stem 44 remains exposed on the outer side wall of the second jaw member 31, such as to allow for the fastener 40 to be inserted into the channel 16.

[0108] With the first jaw set 10 being pre-mounted to the chuck (i.e. in the first condition), the exposed portion of the stem 44 is located into the open-end 17 of the channel and moved into the recessed section 18 such that the second jaw members are coaxially located within the axially extending first jaw members. The fastener 40 is then fastened by a key in the bolt-head 43 such that the first 11 and second 31 jaw members are locked in place together.

[0109] The bolt-head prevents the fastener 40 from sliding out of the channel 16 when the lathe is in operation. Similarly, the ledge 19 and engagement surface 37 prevent the first and second jaw members disengaging.

[0110] Once the first and second jaw sets are mounted together, an item such as a cylindrical piece of wood stock may be inserted into the second jaw members and clamped by inner surface 35 by adjusting the slider-jaws of the chuck.

[0111] It will be understood that the second jaw set is suitable for clamping objects with a smaller diameter than those on the first jaw set. This allows for smaller objects to be machined without swapping the chuck for one suitable for mounting the second jaw set 30 directly thereto, or dismounting the first jaw set 10. This saves both time and cost as it is quicker to assemble and requires less parts.

[0112] The jaw assembly may further comprise a plurality of interchangeable second jaw sets that are suitable for being mounted to the first jaw set in the second condition. The additional jaw sets may be substantially the same but each comprise distinct jaw portions such that they are each specialised for clamping different objects from one another in the second condition (for example, sizes or profiles). This allows for a range of jaw sets to be mounted to the lathe without needing to dismount the first jaw set or requiring multiple chucks. This saves time as jaw sets may require upwards of eight bolts for securing to a chuck, whereas mounting the second jaw sets only require four (for a four piece set) for mounting to the first jaw set. As only one chuck is needed to mount the whole range of second jaw sets, this also saves costs. Furthermore, the fasteners on the second jaw members are more accessible as they protrude radially and are held captive, such that they cannot be dropped.

[0113] The channel 16 also serves as a guide and quick release/attachment mechanism between the parts that can be easily done with one person only. When the fastener 40 is loosely inserted into the channel 16, the operator can let go of the second jaw member 31 which is fully supported by the first jaw member 11 mounted to the lathe (via the chuck). The operator can then use both hands to fasten the parts together.

[0114] In alternative embodiments, the first jaw set is not suitable for clamping an item to be machined in the first condition. The first jaw set serves only as an intermediate member between the lathe chuck and second jaw set such that the second jaw set can be easily mounted and dismounted to a chuck.

[0115] In further embodiments, the first and/or second jaw sets may comprise engagement members that are suitable for engaging with a spigot on an item to be machined.