Patent GB-923005-A (GB)
Title: Improvements relating to toggle fasteners
Inventor: NEILSON WILLIAM
IPC: E05C19/14
Filed: 1959-11-19
Abstract: 923,005. Toggle fastenings. H. K. PORTER CO. (GREAT BRITAIN) Ltd. Oct. 19, 1960 [Nov. 19, 1959], No. 39353/59. Addition to 838,561. Class 44. A toggle fastener comprises a recessed housing adapted to be carried by one of two members to be secured together by the fastener with its front flush with the front surface of such member, a locking lever 5 pivoted near one of its ends to the housing and rockable between a locking position in which its front surface lies flush with the front of the housing and closes part of the recess therein and an unlocked position in which the free end of the lever projects forwardly out of the housing recess, a link 8 pivoted at one of its ends to the locking lever, a connecting member 12 articulated to the other end of the link, the member 12 being rockable about an axis perpendicular of its length and parallel with the front of the housing, the connecting member also being movable longitudinally with respect to the housing and having a hook-like extremity extending from an end of the housing for engaging a complementary element 16 adapted to be carried by the second of said two members and co-operating guide means 19, 20 on the housing and connecting member at a position displaced from the rocking axis for the connecting member and so arranged that relative movement between the connecting member and the housing as a result of rocking of said locking lever from its unlocked to its locking position is confined to a path in which the connecting member extremity first swings in the direction of its mouth and thereafter move towards the housing, the locking lever and link passing over centre as the locking lever approaches its locking position. The housing consists of a pair of spaced parallel side plates and tubular spacer elements 3, 4 uniting the side plates. Bores in the spacer elements receive elements for securing the housing to one of the members to be secured together. The lever 5 consists of two parts 5a, 5b, the part 5b straddling the part 5a and both parts being pivoted to the housing by means of the spacer element 3. The link 8 is pivoted to the locking lever part 5a near its free end by means of a pivot pin 9 and this pivot pin extends through side cheeks of the part 5a into slots 10 in the side cheeks of the part 5b so that the part 5b is connected to the part 5a by the pin 9 but has limited relative angular movement relative to it. A leaf spring 11 on the inner face of the part 5b urges the two parts apart. The connecting member 12 is of channel section and its flanges are provided with longitudinal slots 18 through which the spacer element 3 passes; it is connected to the link 8 by means of a pin 19 and the pin 19 also engages L-shaped slots 20 in the side plates 1, 2 of the housing, the pin 19 and slots 20 constituting the guide means. The hook-like extremity of the connecting member is bifurcated to receive the complementary element 16 which as shown is a T-bolt. In use when the locking lever 5 is swung from its unlocked to its locking position the connecting member 12 is first swung about the spacer element 3, being guided in this movement by the pin 19 engaging the arms 20b of the slots 20 and it is then moved longitudinally this movement being permitted by the slots 18 and being guided by the engagement of the pin 19 with the limbs 20a of the slots 20. A spring-urged latch plate 22 is provided which engages the free end of the locking lever part 5b in its locking position in which position the pivot pin 9 is over dead-centre as compared with the pivot pin 19 and spacer element 3.