Patent GB-793932-A (GB)
Title: Improvements relating to a method of and a tool for driving in pins, nails, studs, or other anchoring pins
IPC: B25C1/02
Filed: 1954-04-28
Abstract: 793,932. Nailing. ANSTALT FUR MONTAGE-TECHNIK. April 28, 1954 [May 8, 1953: Aug. 31. 1953; Nov. 2. 1953; April 15, 1954], No. 12336/54. Class 89(3) In a tool having a nail driving punch slidable in a hand held sleeve, the nail, whilst being driven, is held against lateral deflection by two spaced guides, one of which acts on the shank of the nail adjacent the workpiece into which the nail is being driven, and the other of which comprises a shaped surface on the nail-engaging end of the punch which co-operates with a correspondingly shaped surface on the rear end of the nail in such a manner that the rear end of the nail is centred with respect to the punch. The centring surfaces on the punch and rear end of the nail may comprise a recess in one of these members which receives a correspondingly shaped projection or appendage on the other of these members. Such surfaces preferably are a surface of revolution about the longitudinal axis of the punch or nail, which surface slopes towards that axis, for example, the surface of a cone or part of a sphere. The guide adjacent the workpiece may have a laterally movable part to facilitate the insertion of a headed nail and the removal of the tool after driving a headed nail. The end of the sleeve engaging the workpiece is provided with an enlarged base plate to prevent tilting of the tool. In Fig. 1, a part spherical centring recess 21 in the punch 5 receives the head 22 of a nail 6, the upper surface of the head being of part spherical shape to correspond with the recess 21. The shank of the nail 6 is guided by a washer 19 received in a recess 18 in the bottom surface of the base plate 3. A friction element 10<SP>1</SP>, which may be a spring ring received in an annular groove in the inner wall of the sleeve, prevents recoiling of the punch after the hammer blows. The lower guide may be formed in two relatively movable parts 24, Fig. 4, each having a shaped part which enters a conical recess 25 in the bottom of the sleeve 4. Modified constructions of lower guide members formed in two parts with projections to engage in a conical recess 25 in the sleeve 4 are described with reference to Figs. 3 and 5 (not shown). In the embodiment shown in Figs. 7 and 8, a sleeve 34 having a radial slot 40 at its lower end is rotatably mounted within the handle 32 and can be rotated into the position shown in Fig. 7 in which the slot 40 is aligned with a slot 39 in the handle 32 and base 33 so that a headed nail can be inserted into, or removed from, the tool. The slot 40 has a constriction, Fig. 9, (not shown), which receives the shank of the nail. When the sleeve 34 is rotated to the position shown in Fig. 8 guiding of the shank of the nail is effected. A spring clip 47 locates the sleeve in its two positions. In the embodiment of Fig. 12, the lower guide is comprised by opposed grooves 55, 54 in the base plate 33 and in the lower end of a pivoted catch 48 which is urged inwardly when the tool is held by the operator. In the construction of Fig. 16 the lower recessed ends of centrally pivoted levers 62 are caused to open by upward displacement of a ring 64. When the ring is moved downwardly to the position in Fig. 15 (not shown) the recessed lower ends of the levers 62 come together to form the lower guide. In Fig. 16, the handle is covered by a rubber tube 50<SP>1</SP>. The nails used with the tool may have slightly tapered shanks as described and claimed in Specification 793,933 [Group XXV]. Specification 589,219 also is referred to.