GB1599047A

GB1599047A - Bolts

Info

Publication number: GB1599047A
Application number: GB2107377A
Authority: GB
Original assignee: Newman Tonks Ltd
Current assignee: Allegion UK Ltd
Priority date: 1978-04-13
Filing date: 1978-04-13
Publication date: 1981-09-30

Description

(54) BOLTS (71) We, NEWMAN-TONKS LIMITED, a British Company of Hospital Street, Birmingham, B19 2YG, do hereby declare the invention for which we pray that a Patent may be granted to us and the method by which it is to be performed to be particularly described in and by the following statement: This invention relates generally to bolts and in particular to bolts for doors, such bolts being known as flush bolts.

Where a pair of doors are provided across an opening or passage, the doors being mounted on respective hinges at opposite sides of the opening or passage, one of the doors is often normally positively retained in its closed position by means of a pair of flush bolts. The normally closed door can however be opened, when required, by releasing the flush bolts.

The flush bolts are received in respective vertically extending, recesses, for example, in the edge surface of the door remote from the hinges and each has an outer surface which lies flush with said edge surface of the door. The bolts are disposed adjacent the top and bottom of the door respectively with ends of the bolts respectively terminating substantially flush with respective upper and lower surfaces of the door.

In the closed position of the door, a shoot of the lower bolt extends beyond said lower surface of the door into engagement with a socket received in a surface below the door and a shoot of the top bolt is similarly engaged in a upper frame of the door. Each bolt has an operating knob or lever for moving its shoot into or out of engagement with its associated socket. Alternatively the bolts can be disposed in either the front or rear face of the door, again adjacent the top and bottom of the door respectively.

The object of the invention is to provide a bolt in a simple, convenient and effective manner.

According to the invention a bolt comprises a body portion, an operating lever assembly mounted on the body portion by means of a pivot, a connecting member in the form of a strip extending from said lever towards a shoot, and being operatively connected, at or near one of its ends, to said shoot, and the connecting member being provided at or near its other end with an integral loop defined by a portion of the strip bent up from the surface thereof, part of said operating lever assembly, spaced from said pivot, passing through said loop so that pivotal movement of the operating lever causes linear movement of said shoot away from or towards the body of the bolt.

Conveniently the loop extends over only part of the width of the connecting member.

Most preferably the connecting member is directly operatively connected at or near said one of its ends to said shoot.

The invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a longitudinal, part-sectional view of a bolt constructed in accordance with the present invention, an operating lever of the bolt being in one position, Figure 2 is a similar view to Figure 1, but showing the operating lever in another position, and Figure 3 is a plan view of the bolt with the operating lever in its figure 2 position, a spring of the bolt having been removed for clarity.

The bolt shown in the drawings has an elongate body portion 10 of generally lipped-channel form in transverse crosssection, comprising a front wall 11 defining a flat front face 1 la, and a pair of side walls 12, 13 with lips 14, 15 respectively. At one end of the bolt, the respective end surfaces of the side walls 12, 13 are disposed perpendicular to the front wall 11, but at the other end they are cut away at an angle.

Near said other end of the bolt, a rectangular aperture 16 is provided through the front wall 11. The width of the aperture 16 is equal to the distance between interior surfaces of the walls 12, 13 respectively.

The body portion is made, for example, of brass or aluminium and is produced in several lengths. Moreover, it can be provided with respective short flanges extending normally outwardly from the side walls 12, 13 and providing a continuation of the surface 1 la, if a bolt with a wider front surface is required.

A pivot pin 17 is fixed between the side walls 12, 13 of bolt, the pin 17 extending perpendicularly to the side walls, and having Its respective ends flush with the external surfaces of the side walls 12, 13. The pin is disposed approximately mid-way along the length of the aperture 16 and spaced a short distance from the front face 1 la.

The pin 17 passes through a generally rectangular operating lever 18 of an operaing lever assembly comprising the operating lever 18 and a pivot pin 19. The lever 18 has a width substantially equal to the distance between interior surfaces of the side walls respectively and is of a length approximately equal to one half of the length of the aperture 16. One end of the lever 18 is bifurcated, and the pin 19 passes through the width of the lever from one fork 20 to the other fork 21 of the bifurcated part, as shown in Figure 3. The respective axes of the pivot pins 17, 19 are parallel.

Between the forks 20, 21 is disposed a looped portion 22 of a connecting member 23 which extends in the body portion from the lever 18 to a shoot 29 at the end of the bolt at which the end surfaces of the side walls are disposed perpendicularly to the front wall 11. The pivot pin 19 passes through the looped portion 22.

The connecting member 23 is an elongate strip of sheet metal material of constant thickness. The member 23 has a flat portion 24 which rests upon the interior surface of the front wall 11, a curved portion 25 and a further shorter substantially flat portion 26 joined to the portion 24 by the portion 25.

The flat portion 24 has its free end bent up as at 27 to engage a groove 28 in the shoot 29. Adjacent its end 27, the member 23 is provided with an elongate parallelsided slot 30 having radiused ends. Part of the slot overlies a screw hole 31 in the front wall 11, which in use receives a fixing screw to secure the bolt to the door.

As will be explained, the lever 18 can be moved between the two extreme positions shown in Figures 1 and 2 respectively, to cause the shoot to move linearly out of the end of the bolt. In the position of Figure 2, with the shoot retracted, the position where the flat part 24 of the member joins the radiused part 25 approximately coincides with a transverse edge of the aperture 16.

When in its first position (the shoot 29 being retracted), the operating lever 18 is disposed parallel to the length of the bolt, with one of its surfaces 32 substantially flush with the front surface 1 1a. In this position the flat portion 26 of the connecting member 23 contacts the opposite surface 33 of the lever 18. However, a part of the flat portion 26 disposed centrally between the side walls 12, 13, is bent out of the plane of the portion 26, to form a loop 22 around the pivot pin 19. The loop has an interior surface 34, part of which contacts the pivot pin 19 over approximately one half of its circumference, as shown in Figures 1 and 2.

An end surface 35 of the loop portion 22 lies flush with the surface of the flat portion 26 remote from the lever 18.

A spring 36, in the form of a shaDed sheet-metal strip, is provided in the bolt body to bias the operating lever 18 to one of its two extreme positions. One end 37 of the spring is flat and has a hole 38 therein. A screw hole 39 is formed in the front wall 11 at a position adjacent the end of the bolt remote from the shoot. The hole 39 is of countersunk form, but is formed by displacement of material inwardly to form an annular projection 40. The hole 38 in the spring fits over this projection so that when a fixing screw is passed through the holes 38 and 39, the spring is firmly held in position.

A curved part 41 of the spring extends upwardly, as viewed in Figures 1 and 2, from the end 37 to join, by means of a radiused portion, a vertically upwardly extending part 42. The radiused portion contacts the surface 32 of the operating lever 18 when the lever is in its second position, that is, with the shoot extended.

The part 42 is joined to a slightly curved, downwardly extending part 43 of the spring which has a slightly-upturned, short end portion 44 bearing on the surface of the flat portion of the member 33. The width of each of the parts 37 and 42 of the spring is approximately equal to the distance between the side walls 12, 13 but the part 43 is slightly narrower than the distance between the lips 14, 15. The upper portion of the part 42 has a pair of ears extending from it, at either side of the part 43, one such ear 45 being shown in Figures 1 and 2. The ears fit under the lips 14, 15 respectively and assist introduction of the spring into the body portion.

The shoot 29 comprises a shoot proper 46, extending from a transverse wall part 47, which extends fully between the side walls 12, 13. The shoot proper 46, is generally cylindrical, but the part thereof adjacent the wall part 47 has four equiangularly spaced, sector-shaped cut-outs 48. The groove 28 extends into the lower two cutouts at a position adjacent the wall part 47.

The end 27 of the member 23 is tightly held in the groove so that movement of the part 24 causes linear movement of the shoot 29.

An end cap 49, fitted into the end of the bolt, has a hole for the shoot proper to pass through. An extension 50 of the cap 49 extends in a direction away from the front wall 11 and perpendicularly thereto. A countersunk screw hole 51 for a fixing screw is provided in the extension.

In use, the flush bolt is fitted in a prepared recess in a door so that it is disposed vertically, the surface 1 lea lying flush with the surface of the door in which the recess is provided and the external surface of the end cap 49 and extension 50 lying flush with the upper or lower surface of the door, depending on whether the bolt is fitted at the top or bottom of the door.

A pair of the flush bolts may, for example, be fitted at the top and bottom respectively of a door which is one of a pair of doors closing an opening, for example to a fire exit. One door has no flush bolts and can be opened merely by operating a form of latch, whilst the other door is normally held closed by the bolts. When extended the shoot of the top bolt extends into a socket in the upper frame of the door and the shoot of the lower bolt extends into a socket in the surface below the door. With the shoots extended, the operating lever of each bolt is in the position shown in Figure 1.

To secure the bolt to the door, one screw is passed through the holes 38 and 39 into the door, thus also fixing the spring in position in the body portion of the bolt, and a further screw is passsed through the hole 31 into the door. This further screw passes through the slot 30. The length of the slot is slightly longer than the amount of shoot movement so that the hole 31 is at opposite ends of the slot 30 in the extended and retracted positions of the shoot respectively.

A further screw is passed through the hole 51.

To retract the shoot of a bolt, the lever 18 is pivoted about its pivot pin 17 from the Figure 1 to the Figure 2 position. It is possible for an operator to place his or her finger into the space between the end of the lever and the end of the aperture 16, since the part 41 of the spring is in the form of a concave curve, as viewed from the front of the bolt.

As the lever is pivoted from its Figure 1 position, the forks 20, 21 thereof press on the portions of the member 33 at respective opposite sides of the loop 22. This pressure together with the angular rotation of the lever, forces the portions 25 and 26 of the member to move arcuately about the pivot pin 17, the pivot pin 19 pulling the member 33 together with the shoot 29 to the right, as viewed in Figure 1.

Although the end of the portion 24 of the connecting member is lifted slightly from the wall 11 driving the pivotal movement of the lever 18, its movement is mostly linear, and thus the cylindrical shoot proper 46 moves linearly into the bolt.

The pivotal movement of the lever takes place against the force of the spring, in particular the part 43 thereof. The spring prevents the lever swinging freely and serves to bias it to either one of its extreme positions.

The loop 22 is easily and conveniently formed in the sheet metal strip constituting the connecting member, and obviates the need to attach a further component to the connecting member to provide a hole for a pivot pin to attach the operating lever of the bolt to the member attached directly or indirectly to the shoot.

As stated the width of the front surface of the bolt can be increased if required by providing short flanges extending therefrom.

WHAT WE CLAIM IS: 1. A bolt comprising a body portion, an operating lever assembly mounted on the body portion by means of a pivot, a connecting member in the form of a strip extending from said lever towards a shoot, and being operatively connected, at or near one of its ends, to said shoot, and the connecting member being provided at or near its other end with an integral loop defined by a portion of the strip bent up from the surface thereof, part of said operating lever assembly, spaced from said pivot, passing through said loop so that pivotal movement of the operating lever causes linear movement of said shoot away from or towards the body of the bolt.

2. A bolt as claimed in claim 1 in which said loop extends over only part of the width of the connecting member.

3. A bolt as claimed in claim 1 or claim 2 in which the operating lever assembly comprises an operating lever and a pivot pin, said loop being disposed between a pair of forks defined at one end of said operating lever and said pivot pin passing through said loop and having its respective ends received in said forks.

4. A bolt as claimed in any one of the preceding claims in which the connecting member is directly operatively connected at or near said one of its ends to the shoot.

5. A bolt as claimed in any one of the preceeding claims in which spring means is disposed in the body portion, said spring means acting on said operating lever assembly to resist movement thereof to move the shoot away from or towards the body of the bolt.

6. A bolt as claimed in claim 5 wherein the spring means is a sheet metal strip, one end of which is intended to be fixed to the body and the other end of which bears on

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. countersunk screw hole 51 for a fixing screw is provided in the extension. In use, the flush bolt is fitted in a prepared recess in a door so that it is disposed vertically, the surface 1 lea lying flush with the surface of the door in which the recess is provided and the external surface of the end cap 49 and extension 50 lying flush with the upper or lower surface of the door, depending on whether the bolt is fitted at the top or bottom of the door. A pair of the flush bolts may, for example, be fitted at the top and bottom respectively of a door which is one of a pair of doors closing an opening, for example to a fire exit. One door has no flush bolts and can be opened merely by operating a form of latch, whilst the other door is normally held closed by the bolts. When extended the shoot of the top bolt extends into a socket in the upper frame of the door and the shoot of the lower bolt extends into a socket in the surface below the door. With the shoots extended, the operating lever of each bolt is in the position shown in Figure 1. To secure the bolt to the door, one screw is passed through the holes 38 and 39 into the door, thus also fixing the spring in position in the body portion of the bolt, and a further screw is passsed through the hole 31 into the door. This further screw passes through the slot 30. The length of the slot is slightly longer than the amount of shoot movement so that the hole 31 is at opposite ends of the slot 30 in the extended and retracted positions of the shoot respectively. A further screw is passed through the hole 51. To retract the shoot of a bolt, the lever 18 is pivoted about its pivot pin 17 from the Figure 1 to the Figure 2 position. It is possible for an operator to place his or her finger into the space between the end of the lever and the end of the aperture 16, since the part 41 of the spring is in the form of a concave curve, as viewed from the front of the bolt. As the lever is pivoted from its Figure 1 position, the forks 20, 21 thereof press on the portions of the member 33 at respective opposite sides of the loop 22. This pressure together with the angular rotation of the lever, forces the portions 25 and 26 of the member to move arcuately about the pivot pin 17, the pivot pin 19 pulling the member 33 together with the shoot 29 to the right, as viewed in Figure 1. Although the end of the portion 24 of the connecting member is lifted slightly from the wall 11 driving the pivotal movement of the lever 18, its movement is mostly linear, and thus the cylindrical shoot proper 46 moves linearly into the bolt. The pivotal movement of the lever takes place against the force of the spring, in particular the part 43 thereof. The spring prevents the lever swinging freely and serves to bias it to either one of its extreme positions. The loop 22 is easily and conveniently formed in the sheet metal strip constituting the connecting member, and obviates the need to attach a further component to the connecting member to provide a hole for a pivot pin to attach the operating lever of the bolt to the member attached directly or indirectly to the shoot. As stated the width of the front surface of the bolt can be increased if required by providing short flanges extending therefrom. WHAT WE CLAIM IS:

1. A bolt comprising a body portion, an operating lever assembly mounted on the body portion by means of a pivot, a connecting member in the form of a strip extending from said lever towards a shoot, and being operatively connected, at or near one of its ends, to said shoot, and the connecting member being provided at or near its other end with an integral loop defined by a portion of the strip bent up from the surface thereof, part of said operating lever assembly, spaced from said pivot, passing through said loop so that pivotal movement of the operating lever causes linear movement of said shoot away from or towards the body of the bolt.

the end of the connecting member adjacent said other end thereof.

7. A bolt substantially as hereinbefore described with reference to and as shown in the accompanying drawings.