US3207406A

US3207406A - Center closing press

Info

Publication number: US3207406A
Application number: US251632A
Authority: US
Inventors: Theodore J Bowman
Original assignee: Automated Building Components Inc
Current assignee: Automated Building Components Inc
Priority date: 1963-01-15
Filing date: 1963-01-15
Publication date: 1965-09-21
Anticipated expiration: 1982-09-21

Description

Sept 21, 1965 T. J. BowMAN 3,207,406

CENTER CLOSING PRESS Filed Jan. 15, 1965 Wim I'Il,

.11 TTOR NE V5,

United States Patent O 3,207,406 CENTER CLOSING PRESS Theodore J. Bowman, Opa-locka, Fla., assignor to Automated Building Components Inc., Miami, Fla., a corporation of Florida Filed Jan. 15, 1963, Ser. No. 251,632 12 Claims. (Cl. 227-152) This invention relates to a center closing press and more particularly to a hydraulically operated C-clamp press for driving metal connectors into structural wood joints.

Fluid operated C-clamps or vises are well known and are used in a great many operations for holding workpieces or material to be operated upon. In most instances. the C-clamp is itself portable and is provided with a single movable jaw, the stationary jaw being initially placed against one surface of the workpiece. In instances where the C-clamp is stationary or secured to a support such as a work bench or table, the workpiece is usually brought into engagement with the stationary jaw and the movable jaw then drawn into engagement with the other surface of the workpiece.

The present invention relates to a C-clamp type press wherein both jaws are movable to drive metal connectors into the opposite sides of a structural wood joint. The novel press of the present invention is of particular utility in situations where the workpiece or material to be operated upon is either relatively heavy or not otherwise easily moved into engagement with the surface of one jaw of the lixed or stationary press. In addition a novel adjustable compensating spring arrangement is provided to assure rapid and ,uniform movement of both press jaws into driving engagement with the workpiece. The press of the present invention is particularly adapted for conveyorized operation in forming the joints of relatively large structural elements such as house roof trusses and the like.

It is therefore one. object of the present invention to provide a novel center closing press.

Another object of the present invention is to provide a novel C-clamp type fluid operated press.

Another object of the present invention is to provide a novel uid operated press for driving metal connectors into wooden joints.

Another object of the present invention is to provide a novel compensating spring arrangement for a center closing C-clamp press.

These and further objects :and advantages of the invention will be more apparent upon reference to the following specification, claims and appended drawings wherein:

FIGURE 1 is an elevational View of the novel press of the present invention;

FIGURE 2 is a side view of the press of FIGURE l; and

FIGURE 3 is a side view similar to that of FIGURE 2 with parts in section.

Referring to the drawings, the novel press of the present invention generally indicated at in each of FIG- lURES 1 through 3 comprises a C-shaped frame 12, an

upper movable jaw 14 and a lower movable jaw 16. Frame 12 is made of a pair of

side plates

18 and 20 both of identical C-shape joined by a cross bar 21 and screws 22. The cross bar 21 receives screws 24 and 26 which removably support the upper jaw 14 as shown in FIG- URE l. j

Resting on a table 28 or other suitable support are a pair of

boards

30 and 31 to be joined in an end type butt joint at 33. The boards are joined by a pair of metal connectors such as upper connector 34 and lower connect- 3,207,406 Patented Sept. 21, 1965 ICC or 36 which may be of the type disclosed in U.S. Patent No. 2,877,520. The portions of the

boards

30 and 31 to be joined extend over a cut-out section 29 in the edge of the table 28 which provides clearance for the

jaws

14 and 16.

The

connectors

34 and 36 are manually placed against the jaws and held in the proper position by suitable magnets such as

permanent magnets

35 and 37 embedded in the jaws.

Lower jaw 16 is secured by screws 38 shown in FIG- URE 3 to a collar 40 press fitted or otherwise rigidly connected to the top of a plunger or piston 42. Piston 42 is received in a cylinder 44 in turn slidably mounted in a support tube 46. Welded to the support tube is a supporting ange 48 having apertures 50 for connection by screws, bolts or the like to a rigid, stationary base indicated by the hatching at 52.

Support tube 46 is provided with a transverse pin 54 upon which rests one end of a relatively heavy compression spring 56. The upper end of compression spring 56 engages the bottom 58 of cylinder 44. A supply pipe 60 passes through a suitable aperture in the wall of the cylinder 44 and communicates with the interior of the cylinder. The space between the bottom 58 of the cylinder and the bottom of the piston 42 is shown as filled with hydraulic iluid such as oil 62. It is apparent that other liquids or gases such as water or air can be used to drive the press.

Pipe 60 is rigidly secured in the wall of cylinder 44 and the support tube 46 is provided with an elongated vertical slot 64 to permit upward and downward movement of the supply pipe 60 with upward and downward movement of the cylinder 44. A socket 66 internally threaded as at 68 is secured to the pipe 60 for the reception of a flexible hydraulic line indicated diagrammatically at 70. Line 70 is connected through a three-way valve 72 to the high pressure output line 74 of a hydraulie pump 76 and to a return line 78 leading either to the sump of the hydraulic system or to the low pressure input side of the pump 76. It is understood that valve 72 alternatively connects the line 70 either to line 74 or to line 78, so that hydraulic fluid is alternatively supplied to and exhausted from the oil chamber between the piston 42 and the bottom of cylinder 44.

The lower side of the C-shaped frame 12 is welded or otherwise suitably attached to the opposite sides of a ring 80 having internal teeth 81 engaging similar teeth on the upper end of cylinder 44. In this way the frame 12 is rigidly attached to and carried by the cylinder. As a result, upward and downward movement of the cylinder 44 results in upward and downward movement of the upper jaw 14.

As best seen in FIGURES 1 and 2, a pair of

tension springs

82 and 84 are connected between the lower jaw 16 and the support flange 48. The tension of these two springs may be adjusted by turning the locking nuts 88 on the lower ends of hook bolts 90. If desired, a suitable indicia strip 92 may be secured to one of the plates such as plate 20 for aligning the press with the top of table 28.

In operation, connector 34 is first placed against upper jaw 14 and held in place by magnet 35. The lower connector 36 is placed on the lower jaw 16 directly beneath the upper connector 34. Valve 72 is then actuated either manually or automatically to connect high pressure line 74 with input'line 70 so as to supply high pressure fluid to the underside of pist-on 42. The action of the pressure fluid is to drive the piston 42 upwardly with respect to the cylinder 44and at the same time drive the cylinder 44 itself downwardly in the support pipe 46.

Upward movement of the piston 42 carrying lower jaw 16 is resisted by the tension springs 82 while downward movement of the cylinder 44 carrying the frame 12 and hence uppper jaw 14 is at the same time resisted by the larger compression spring 56. It is preferred that the springs be chosen so that the resistance of spring 56 is equal to the combined resistance of both

springs

82 and 84 although the selection of the springs is not critical. The springs acting against the opposite movable jaws of the press provide a compensating action to assure that both jaws will move simultaneously towards each other to drive the

plates

34 and 36 from the solid line position to the dashed line position illustrated in FIGURE 3 into the opposite surfaces of the

boards

30 and 31. Once the connectors are completely driven, valve 72 is again actuated, disconnecting supply line 70 from high pressure line 74 and connecting to low pressure line 78. With the oil 62 in the cylinder connected to the exhaust side of the hydraulic system, the compensating

springs

56, 82 and 84 serve the dual purpose of return springs drawing the piston 42 downwardly and pushing the cylinder 44 upwardly to squeeze oil from the chamber and back out through the pipe 60 and valve 72 to the return line 78. This return movement or opening of the jaws is limited by the equilibrium position of the spring system indicated by the rest position of the press illustrated in the respective figures of the drawing.

It is apparent from the above that the present invention provides a novel center closing press, particularly suited for use in driving metal connectors into structural lumber. While the press as shown is illustrated for use in conjunction with a table supported wood structure, it is apparent that the table 28 could be replaced by a movable conveyor with the press position adjacent the conveyor edge. Likewise, although shown utilizing hydraulic fluid, the press may be operated with liquids other than oil -and may be pneumatically operated if desired. Novel features of the press include movement of both jaws with respect to a stationary support so as to make it possible to drive connectors into both the upper and lower surfaces of the wood elements to be joined, which action is particularly advantageous for the construction of structural timber such as roof trusses and the like which are of relatively large size and are not easily movable into engagement with one of the press jaws.

Additional important features include the provision of an adjustable compensating spring arrangement, which springs function not only as return springs for the two movable jaws, but act to automatically compensate for the different resistant forces acting on the jaws to insure simultaneous movement of both jaws toward and away from the workpiece. Adjustment of the tension springs 82 and 84 by means of nuts 88 makes it possible to easily modify the position at which the jaws will completely close so as to insure uniform closing movement of the jaws when lumber of a different thickness is joined in the press. The device is of relatively simple, rugged construction requiring a minimum of upkeep and repair.

The simultaneous movement of both jaws provides for a minimum of joint distortion during pressing and makes possible a strong, tight joint.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive,

the scope of the invention being indicated by the appended `claims rather than by the foregoing description, and all y means for supplying pressure uid between one end of said 4 cylinder and said piston to move said jaws substantially simultaneously toward each other. v

2. A press according to claim 1 wherein at least one of said jaws is provided with magnetic means for holding a metal connector.

3. A press comprising a rigidly mounted support tube, a cylinder having a closed end slidable in said support tube, a frame including a first press jaw carried by the other end of said cylinder, a piston slidable in said cylinder and carrying a second press jaw, and means for introducing a pressure fluid between said piston and said closed end of said cylinder to produce closing movement of said jaws.

4. A press comprising first movable means supporting a first jaw, second movable means spaced from said first means and carrying a second jaw, means for introducing a pressure fluid between said first and second means to move said jaws substantially simultaneously toward each other, and resilient means acting against both said first and second movable means to resist the movement of said jaws.

5. A press for driving metal connectors comprising a movable cylinder and piston, a C-shaped frame carrying a first jaw mounted on said cylinder, a second jaw mounted on said piston, means for moving said cylinder and piston to move said jaws substantially simultaneously toward each other, and spring means acting against both said cylinder and said piston to resist the movement of said jaws.

6. A center closing press for driving metal connectors comprising a stationary support, ya hollow cylinder having a closed end slidable in said support, a C-shaped frame carrying a first jaw mounted on the other end of said cylinder, a piston having one end slidable in said cylinder, a second jaw mounted on the other end of said piston, and means for introducing pressure fluid between said closed end of said cylinder and said one end of said piston to produce closing movement of said jaws.

7. A press according to claim 6 including compression spring means between said closed end of said cylinder and a portion of said support for resisting closing movement of said first jaw, and tension spring means for resisting closing movement of said second jaw.

8. A press according to claim 7 wherein the resistive forces of said tension and compression spring means are equal.

9. A center closing press` for driving metal connectors comprising a support tube having a flange for rigidly connecting said tube to a stationary support, a hollow cylinder having a closed end slidable in said support tube, a C-shaped frame carrying a first jaw mounted on the other end of said cylinder, a piston having one end slidable in said cylinder, a second jaw mounted on the other end of said piston, means for introducing pressure between said closed end of said cylinder and said one end of said piston to produce closing movement of said jaws, ,a compression spring bearing against said closed end of said cylinder for resisting closing movement of said first jaw, and a pair of tension springs coupling said flange to said second jaw for resisting closing movement of said second jaw.

10. A press according to claim 9 including permanent magnets in said jaws for holding metal connectors.

11. A center closing press for driving metal connectors comprising a vertical support tube having a flange for rigidly connecting said tube to a stationary support, a hollow cylinder having a closed lower end telescopingly received in the upper end of said support tube, a vertically extending C-shaped frame mounted on the upper end of said cylinder and carrying an upper press jaw, a piston having its lower end telescopingly received in the upper end of said cylinder, a lower press jaw mounted on the upper end of said cylinder in vertical alignment with said upper press jaw, means for introducing la hydraulic pressure fluid between the lower ends of said piston and cylinder to produce closing movement of both said jaws, stop means in the lower end of said support tube, a compression spring between said stop means and the lower end of said cylinder for resisting downward movement of said upper press jaw, land a pair of tension springs connected between said lower jaw and said ange for resisting upward movement of said lower jaw.

12. A press according to claim 11 wherein said support tube is provided with an elongated vertical slot, and said hydraulic pressure iluid introducing means comprises a feed tube communicating with the interior of said cylinder and passing through said slot.

References Cited by the Examiner UNITED STATES PATENTS Spaulding 100--264 X Purcell 1GO- 269 Osborne et al. 1-44.4 Juilfs 1-44.4 Moehlenpah et al. 1 149 10 GRANVILLE Y. CUSTER, JR., Primary Examiner.

Claims

6. A CENTER CLOSING PRESS FOR DRIVING METAL CONNECTORS COMPRISING A STATIONARY SUPPORT, A HOLLOW CYLINDER HAVING A CLOSED END SLIDABLY IN SAID SUPPORT, A C-SHAPED FRAME CARRYING A FIRST JAW MOUNTED ON THE OTHER END OF SAID CYLINDER, A PISTON HAVING ONE END SLIDABLE IN SAID CYLINDER A SECOND JAW MOUNTED ON THE OTHER END OF SAID PISTON, AND MEANS FOR INTRODUCING PRESSURE FLUID BETWEEN SAID CLOSED END OF SID CYLINDER AND SAID ONE END OF SAID PISTON TO PRODUCE CLOSING MOVMENT OF SAID JAWS.