For want of knowledge I have called this a Sliding Blind Tapered Dovetail mortise & tenon, is there a better known name?
Recovering the teak timber from an old Indian planter chair (where the arms are in 2 parts, the upper part being fixed and the lower part can be swung forward as leg rests) I was intrigued by the secret joint that had been used between the upper armrest and front leg. The top of the front leg is cylindrical (to allow the lower arm rest to swing round) and on the top there is a tapered dovetail tenon, getting wider towards the rear.
In the underside of the armrest there is a long blind mortise, the rear section able to take the whole of the tenon on the leg, with the front part being the female equivalent of the male tenon.
When assembling the lower arm is placed over the cylindrical section of the chair leg, then the upper arm is placed forward of its final position and dropped onto the tenon. It is then pushed backwards to its final location so that the tapered dovetail tenon engages with the tapered dovetail section of the mortise and is held in this position by a blind mortise and tenon joint pinned with wooden dowels at the junction of the back of the armrest and chair back. Indeed, originally all joints of this chair were hand cut glue free pinned motise and tenon of some sort and only later repairs introduced the screws, nail, pins and glue which made restoration out of the question.
I hope that the attached poor sketch can be viewed.
Recovering the teak timber from an old Indian planter chair (where the arms are in 2 parts, the upper part being fixed and the lower part can be swung forward as leg rests) I was intrigued by the secret joint that had been used between the upper armrest and front leg. The top of the front leg is cylindrical (to allow the lower arm rest to swing round) and on the top there is a tapered dovetail tenon, getting wider towards the rear.
In the underside of the armrest there is a long blind mortise, the rear section able to take the whole of the tenon on the leg, with the front part being the female equivalent of the male tenon.
When assembling the lower arm is placed over the cylindrical section of the chair leg, then the upper arm is placed forward of its final position and dropped onto the tenon. It is then pushed backwards to its final location so that the tapered dovetail tenon engages with the tapered dovetail section of the mortise and is held in this position by a blind mortise and tenon joint pinned with wooden dowels at the junction of the back of the armrest and chair back. Indeed, originally all joints of this chair were hand cut glue free pinned motise and tenon of some sort and only later repairs introduced the screws, nail, pins and glue which made restoration out of the question.
I hope that the attached poor sketch can be viewed.
