WO2001027422A1

WO2001027422A1 - Scissor arm

Info

Publication number: WO2001027422A1
Application number: PCT/US2000/027950
Authority: WO
Inventors: Nicholas Weiland
Original assignee: Southco, Inc.
Priority date: 1999-10-11
Filing date: 2000-10-11
Publication date: 2001-04-19
Also published as: AU8005500A; TW496924B

Abstract

A scissor arm having push-push operation is disclosed. The scissor arm comprises a first arm (12) and a second arm (14) which are pivotally connected to one another such that the arms can be moved relative to one another between a closed and an open configuration. A biasing means (18) biases the first and second arms toward the open configuration. One of the arms is provided with a receptacle (28) for housing a latch mechanism while the other arm is provided with a keeper (42) which is releasably engaged by the latch mechanism to hold the scissor arm in the closed configuration.

Description

SCISSOR ARM

BACKGROUND OF THE INVENTION

1. Field of Invention

This invention relates generally to a scissor arm with push-push operation.

2. Brief Description of the Related Art

Latches having Push-push operation are known in the art. An example of this type of latch is shown in U.S. Patent No. 4,655,489, issued on April 7, 1987, to Robert H. Bisbing. The latch disclosed in this patent operates by capturing a keeper attached to a door or panel when the keeper is initially pushed into the latch housing. The keeper is released by again pushing the keeper into the housing to disengage the keeper from a catch within the housing, hence the term push-push latch.

SUMMARY OF THE INVENTION

The present invention relates generally to a scissor arm with push-push operation. The scissor arm comprises a first arm and a second arm which are pivotally connected to one another such that the arms can be moved relative to one another between a closed and an open configuration. A biasing means biases the first and second arms toward the open configuration. One of the arms is provided with a receptacle for housing a latch mechanism, while the other arm is provided with a keeper which is releasably engaged by the latch mechanism to hold the scissor arm in the closed configuration. In a preferred embodiment, the latch mechanism is of the push- push type, although other types of latches may also be used with the scissor arm of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a perspective view of an embodiment of a scissor arm in accordance with the present invention, the scissor arm being shown in an open position. Fig. 2 is a front elevational view of the scissor arm of Fig. 1. Fig. 3 is a perspective view of the scissor arm of Fig. 1 shown in a position just prior to a closed position.

Fig. 4 is a front elevational view of the scissor arm of Fig. 3.

Figs. 5-8 are perspective, front elevational, left side and top plan views of a gear arm of the scissor arm of Fig. 1.

Figs. 9-12 are perspective, front elevational, left side and top plan views of a damper arm of the scissor arm of Fig. 1.

Figs. 13-16 are perspective, front elevational, left side and top plan views of a linkage of the scissor arm of Fig. 1. Fig. 17 is a perspective view of a second embodiment of the scissor arm of the present invention, shown in the closed configuration.

Fig. 18 is a perspective view of a second embodiment of the scissor arm of the present invention, shown in the open configuration.

Fig. 19 is a left side view of a second embodiment of the scissor arm of the present invention, shown in the open configuration.

Fig. 20 is a right side view of a second embodiment of the scissor arm of the present invention, shown in the open configuration.

Fig. 21 is a left side view of a second embodiment of the scissor arm of the present invention, shown in the closed configuration.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings in detail, wherein the same reference numerals are used consistently to refer to the corresponding structural element throughout the appended drawings, in Figs. 1-16 is illustrated a scissor arm in accordance with an embodiment of the present invention. The scissor arm 10 as shown in the perspective view of Fig. 1 includes in the present embodiment, as portions thereof, first and second arms 12 and 14 comprising a gear arm and a damper arm, a linkage member or linkage bar 16, and a biasing means comprising a compression spring 18. The details of the scissor arm of the present embodiment will be described in more detail below.

The gear arm 12 is illustrated in detail in Figs. 5-8. The gear arm 12 in this embodiment includes a pair of opposing walls 20 and 22 proximate a first end. The walls 20 and 22 include a pair of aligned apertures 24 and 26 and with the wall 22 also including a length of teeth or serrations 27 along a bottom surface that is generally arcuate in configuration. The gear arm 12 also includes an extension 28 generally boxlike in configuration in this embodiment and positioned proximate a second end and extending from its bottom surface. The extension 28 includes a cavity 30 within its terminating end and which extends in a direction of the bottom surface, as is illustrated in dotted lines. The gear arm 12 in this embodiment also includes at its second end a through opening 32 and an extension arm or curved portion 34 terminating in a peg or boss 36.

The damper arm 14 is illustrated in detail in Figs. 9-12. The damper arm 14 includes in this embodiment a through opening 40 and a keeper 42 proximate a first end. The damper arm 14 also includes proximate a second end a through opening 44 and four bosses 46a-46d arranged in pairs of two attached to opposing sides.

The linkage bar in accordance with the present embodiment is illustrated in detail in Figs. 13-16. The linkage bar 16 includes a pair of walls 50 and 52 at a first end and the walls 50 and 52 including a pair of aligned apertures 54 and 56. The linkage 16 further includes a boss or peg 57 at a second end and a projection or abutment 58 extending from its bottom surface positioned between the first and second ends.

The gear arm 12, damper arm 14 and linkage 16 in the present embodiment are preferably made from reinforced nylon, however, it should be understood that other materials and/or manufacturing processes can also be utilized for the same purpose. The assembly of the scissor arm 10 will now be described. The gear arm 12 is attached to the damper arm 14 by the bosses 46b and 46d which extend in the aligned apertures 24 and 26. The damper arm 14 is attached to the linkage 16 by the bosses 46a and 46c which extend in aligned apertures 54 and 56. In the present embodiment, the resiliency of the opposing walls 20 and 22 of the gear arm 12 and the resiliency of the opposing walls 50 and 52 of the linkage 16 allow the portions to be snap fit together without additional tools or retainers. The compression spring 18 is mounted by having its terminating ends attached to the bosses 36 and 57 of the gear arm 12 and linkage 16, respectively. As should be understood, other types of biasing means can also be used for the same purpose, such as a torsion spring or elastomeric spring, to name a few. In addition, in the present embodiment, the gear arm 12 further includes a latch assembly 60 positioned in the cavity 30 of extension 28 and which is adapted to operate with the keeper 42 of the damper arm 14, such as illustrated in dotted lines in Fig. 3. Thus the extension 28 acts as the housing for the latch assembly 60. Preferably, the latch 60 is of the push-push type requiring a pushing motion for both latching and unlatching. One type of push-push latch is disclosed in U.S. Patent No. 4,655,489, the complete disclosure of which is incorporated by reference. Any other known type of push-push latch may also be used. In addition, other latches which may be accessed for actuation when the scissor arm 10 is in the closed configuration may also be employed depending upon the intended application. Such latches include but are not limited to latches actuated by a solenoid which is operated either remotely or by hardwire connection. The damper arm 14 further includes a damper 62 preferably of the rotary type having a pinion gear wheel 63 positioned in opening 40, such as illustrated in Fig. 1. Such types of dampers are commercially available and use a thick viscous substance to dampen the rotation of the gear wheel 63. Also, friction clutches may be used to dampen the rotation of the gear wheel 63. Damping the pivotal movement of the second arm 14 relative to the first arm 12 is advantageous in that it allows the scissor arm 10 to open in a slow and controlled manner so as not to startle or injure a user.

The operation of the scissor arm 10 of the present embodiment will now be described. The scissor arm 10 is adapted for any of a number of different applications, such as to secure one member relative to another member, for example, pop-out trays, sliding ashtrays and the like. As an example, the arm may be pivotally connected at the opening 32 to a support structure (not shown) while the arm 14 is pivotally connected at the opening 40 to a sliding tray (not shown) slidably supported by the support structure. The sliding tray can then be moved between a retracted and an extended position by a push-push action. Thus, the scissor arm 10 can, for example, be used to provide a concealed pop-out tray in the dashboard of a vehicle. The scissor arm 10 in use can have the gear arm 12 attached to one member, such as by a fastening member extending in opening 32, and the damper arm 14 attached to a second member, such as by a fastening member extending in opening 40. As will be described below, one advantage of the scissor arm 10 is that it provides in a single device the features of a push-push latch, a spring to bias to an open position and a damping of the opening motion.

The scissor arm 10 is shown in an open position in Figs. 1 and 2 and in a position near a closed position in Figs. 3 and 4. As discussed above, the keeper 42 is fastened with the latch 60 in a closed position. The scissor arm 10 is moved into the closed position by application of force preferably on the member attached to the damper arm 14. However, it should be understood that the force can be applied directly to the damper arm 14 or to the gear arm 12 or member attached to gear arm 12. The connection of the damper arm 14 and gear arm 12 provides for the pivotal motion of the arms 12 and 14 relative to one another. The connection of the damper arm 14 and the linkage 16 allows for pivotal motion of the linkage bar 16 relative to the arm 14. The provision of the linkage bar 16 allows the moment arm of the force exerted by the spring 18 about the pivotal attachment of the arms 12 and 14 to remain relatively constant. Thus a user will not have to overly exert him or her self when initially moving the scissor arm 10 from the open to the closed configuration. Also the linkage bar 16 provides a geometry which prevents the bending of the spring 18 as the scissor arm 10 from the open to the closed configuration. The projection 58 provides an abutment for the engagement of the arm 14. At some point during the movement of the scissor arm 10 from the open to the closed configuration, the platform 58 of the linkage 16 will engage the arm 14 and be kept in that position, relative to the arm 14, by the spring 18. Thereafter, the arm 14 and the linkage bar 16 will pivot as a unit relative to the arm 12. The arrangement of the arm 14, the linkage 16, and the spring 18 allows the range of the pivotal motion of the arm 14 relative to the arm 12 to exceed 90 degrees. As shown in Figs. 1 and 3, the projection 58 of linkage 16 is only brought into contact with damper arm 14 as the damper arm 14 is moved into the closed position. The damping gear 63 is engaged to the gear teeth 27 of the gear arm 12 such that as the damping arm 14 is moved between the open and closed positions, the pinion gear 63 rotates about its own axis and thus dissipates the energy of the spring 18 in the viscous substance which resists the rotation of the gear 63.

The movement to the closed position is against the spring force of biasing member 18. Once the arm 14 is in the near closed position of Figs. 3 and 4, the keeper 42 is pushed into the latch assembly 60 to releasably retain the scissor arm 10 in the closed configuration. Movement from the closed position to the open position of Fig. 1 is accomplished by pushing the keeper 42 further into the latch assembly 60 to unfasten the latch 60 and keeper 42 and allow the arm 14 to move to the open position under the power of the spring 18. The force of spring 18 biases the damper arm 14 to the open position. The damping gear 63 provides damping or resistance to the opening motion of the damper arm 14 by engagement with the gear teeth 27 of gear arm 12. In this embodiment, the damping gear is bi-directional, in that damping is provided on both opening and closing motions of the damping arm 14. In other embodiments, the damping gear 63 can be modified to provide a single direction damping as the damping arm 14 is moved to the closed position.

Referring to Figs. 17 to 21 , a second embodiment of the scissor arm 10a can be seen. The scissor arm mechanism 10a includes a first arm 12a and a second arm 14a pivotally attached to the first arm 12a. The second arm 14a is movable relative to the first arm 12a between a closed position and an open position. The scissor arm mechanism 10a also includes means 18a for biasing the second arm 14a toward the open position, and means 60a for releasably holding the second arm 14a in the closed position.

The means 60a for releasably holding the second arm 14a in the closed position includes a keeper 42a attached to the second arm 14a and a latch assembly 60 provided in a latch assembly housing 28a fixed to the first arm 12a, although the positions of the keeper 42a and the latch assembly 60 may be reversed. The latch assembly 60 releasably engages the keeper 42a when the second arm 14a is in the closed position. As with the first embodiment, the latch assembly 60 is preferably of a push-push type. The means 18a for biasing the second arm 14a toward the open position includes a coil spring 18 having a first end and a second end. The first end of the coil spring 18 is engaged to the peg 36. The means 18a for biasing the second arm 14a toward the open position further includes a linkage bar 16a having a first end and a second end. The second end of the linkage bar 16a is pivotally connected to the second arm 14a. The first end of the linkage bar 16a is connected to the second end of the coil spring 18.

The first arm 14a and the second arm 12a are attached to one another at a pivotal attachment 64. The first arm 12a has a substantially straight portion 12b and a curved portion 12c located distally from the pivotal attachment 64. The substantially straight portion 12b has a longitudinal axis and the curved portion 12c terminates at an end offset from the longitudinal axis of the straight portion 12b so as to form an offset end. A peg 36 is provided at the offset end of the curved portion 12c. The first end of the coil spring 18 is engaged to the peg 36. As with the first embodiment, the scissor arm mechanism 10a includes means 65 for providing controlled movement of the second arm 14a from the closed position to the open position. The means 65 for providing controlled movement includes means 62 for damping pivotal movement of the second arm 14a relative to the first arm 12a. The means 65 for providing controlled movement further includes a plurality of gear teeth 27a arranged along a circular arc having a center of curvature that is coincident with the pivotal attachment 64. The plurality of gear teeth 27a are in a fixed position relative to the first arm 12a. The means 62 for damping are supported by the second arm 14a. As before, the means 62 for damping include pinion gear wheels 63 supported for rotational motion about an axis fixed in position relative to the second arm 14a. The pinion gear wheels 63 are in engagement with the plurality of gear teeth 27a and the rotation of the pinion gear wheels 63 is viscously damped.

The embodiments 10 and 10a are identical in nearly all respects, the important differences being noted below. The embodiment 10a has two damping pinion gears 63. The embodiment 10a has its plurality of gear teeth 27a formed in an arcuate member 66 which is attached to the first arm 12a. The embodiment 10a has means 68 for guiding the keeper 42a into the latch assembly 60 even when the scissor arm 10a is subjected to loads transverse to a plane defined by pivotal motion of the second arm 14a relative to the first arm 12a. The means 68 for guiding includes a rod 70 projecting from the second arm 14a and means 72 provided proximate the latch assembly 60 for receiving the rod 70. The means 72 defines an opening 74 for receiving and guiding the rod 70.

In addition, the linkage bar 16a lacks the projection 58. In embodiment 10a the function of the projection 58 is performed by the abutment 76 attached to the second arm 14a. The abutment 76 engages the linkage bar 16a as the arm 14a gets nearer to the closed position. Further, the arm 14a has a bracket 78 which partially surrounds the arcuate member 66. An abutment 80 is provided on the arcuate member 66. The bracket 78 engages the abutment 80 to limit the amount of opening of the arm 14a relative to the arm 12a. It is understood that the above description of the present invention is susceptible to considerable modifications, changes and adaptations by those skilled in the art, and that such modifications, changes and adaptations are intended to be considered within the scope of the present invention.

Claims

What is claimed is:

1. A scissor arm mechanism comprising:

(a) a first arm;

(b) a second arm pivotally attached to said first arm, said second arm being movable relative to said first arm between a closed position and an open position;

(c) means for biasing said second arm toward said open position; and

(d) means for releasably holding said second arm in said closed position.

2. The scissor arm mechanism of claim 1 , wherein said means for releasably holding said second arm in said closed position includes a keeper attached to one of said first and second arms and a latch assembly provided in a fixed position relative to another one of said first and second arms, such that said latch assembly releasably engages said keeper when said second arm is in said closed position.

3. The scissor arm mechanism of claim 2, wherein said means for releasably holding said second arm in said closed position further includes a latch assembly housing fixed to said another one of said first and second arms, said latch assembly being received within said latch assembly housing.

4. The scissor arm mechanism of claim 2 or 3, wherein said latch assembly is of a push-push type.

5. The scissor arm mechanism of claim 1 , wherein said means for biasing said second arm toward said open position includes a coil spring having a first end and a second end, said first end of said coil spring being operably linked to said first arm and said second end of said coil spring being operably linked to said second arm.

6. The scissor arm mechanism of claim 5, wherein said means for biasing said second arm toward said open position further includes a linkage bar having a first end and a second end, said second end of said linkage bar being pivotally connected to said second arm and said first end of said linkage bar being connected to said second end of said coil spring.

7. The scissor arm mechanism of claim 6, wherein said first arm and said second arm are attached to one another at a pivotal attachment, said first arm has a substantially straight portion and a curved portion located distally from said pivotal attachment, said substantially straight portion has a longitudinal axis, said curved portion terminating at an end offset from said longitudinal axis so as to form an offset end, and said means for biasing said second arm toward said open position further includes a peg provided at said offset end, said first end of said coil spring being engaged to said peg.

8. The scissor arm mechanism of claim 1 , further comprising means for providing controlled movement of said second arm from said closed position to said open position.

9. The scissor arm mechanism of claim 8, wherein said means for providing controlled movement includes means for damping pivotal movement of said second arm relative to said first arm.

10. The scissor arm mechanism of claim 9, wherein said means for providing controlled movement further includes a plurality of gear teeth arranged along a circular arc, said plurality of gear teeth being in a fixed position relative to said first arm, wherein said means for damping is supported by said second arm and comprises at least one pinion gear wheel supported for rotational motion about an axis fixed in position relative to said second arm, said pinion gear wheel being in engagement with said plurality of gear teeth, and wherein rotation of said pinion gear wheel is viscously damped.

11. The scissor arm mechanism of claim 10, wherein said means for damping comprises a second pinion gear wheel supported for rotational motion about an axis fixed in position relative to said second arm, said second pinion gear wheel being in engagement with said plurality of gear teeth, and wherein rotation of said second pinion gear wheel is viscously damped.

12. The scissor arm mechanism of claim 10 or 11 , wherein said plurality of gear teeth are integral with said first arm.

13. The scissor arm mechanism of claim 10 or 11 , wherein said plurality of gear teeth are formed in an arcuate member attached to said first arm.

14. The scissor arm mechanism of claim 2, further comprising means for guiding said keeper into said latch assembly even when the scissor arm mechanism is subjected to loads transverse to a plane defined by pivotal motion of said second arm relative to said first arm.

15. The scissor arm mechanism of claim 14, wherein said means for guiding includes a rod projecting from said second arm and means provided proximate said latch assembly for receiving said rod.